Figure 1-1: Measuring voltage using 10 channels ADC and displaying it through the LCD.
Download demo file ADC10Ch.7z
Purpose
To measure the voltage with a 10-channel analog to digital module and display the reading on the LCD display. With the help of a switch, readings from different channels can be seen as in Figure 1‑1.
Figure 1-1: Measuring voltage using 10 channels ADC and displaying it through the LCD.
Figure 1‑2 shows a Simulink Model for 10 channels ADC and displaying the voltage readings through LCD display. Subsystem model consists of a following attributes.
Figure 1-2: Simulink Model for reading voltage using 10-channel and displays the results through the LCD
After downloading the model into STM32F4DISCOVERY, the module will start reading the voltage at 10 channels every 0.1 seconds. The values of the voltages will be stored in 10 variables (V1, V2, … , V10). This is shown in Figure 1‑3.
Figure 1-3: Subsystem for reading the voltage from 10 channel analog input
There are 10 readings which need to be displayed on a single LED screen and this is not possible. Therefore subsystem is made so to display readings from 0 to 3 at the start-up page. With the help of the switch, the display can be changed.
Figure 1-4: Subsystem for displaying the readings of the channels (0 to 3) on the LCD display
Figure 1‑5 shows the subsystem for adjusting the page number on display and receive input signal from two switching ports to see the next page and previous page. The subsystem will not work if no swtich is pushed.
Figure 1-5: Subsystem for adjusting the LCD display
MATLAB is a programming platform designed specifically for engineers and scientists. The heart of MATLAB is the MATLAB language, a matrix-based language allowing the most natural expression of computational mathematics.
Simulink® is a block diagram environment for multidomain simulation and Model-Based Design. It supports system-level design, simulation, automatic code generation, and continuous test and verification of embedded systems. Simulink provides a graphical editor, customizable block libraries, and solvers for modeling and simulating dynamic systems. It is integrated with MATLAB®, enabling you to incorporate MATLAB algorithms into models and export simulation results to MATLAB for further analysis.
Waijung 2 is Aimagin's 2nd generation Simulink blockset. Waijung 2 blockset currently supports ESP32 microcontrollers by Espressif. Waijung 2 can be used to develop programs for ESP32 using Matlab / Simulink environment.
For more information visit,
What is Matlab?
What is Simulink?
Simulink documentation
Getting started with Matlab
Getting started with Simulink for controls
Waijung 2
Previous: System Requirements
Next: How to get Waijung 2?
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| ADC Module | 1--2 | The ADC driver API supports ADC1 (8 channels, attached to GPIOs 32 - 39), and ADC2 (10 channels, attached to GPIOs 0, 2, 4, 12 - 15 and 25 - 27). |
| ADC Resolution | 9Bit--10Bit--11Bit--12Bit | Specify sample time for the block |
| ADC attenuation | 0DB--2.5DB--6DB--11DB | Select attenuation |
| Select ADC channels | Select channel pins |
Use this block for the application which need to process analog signal by software. Example, reading level of analog sensor (Temperature, Pressure, etc.), measure voltage and current from sensing circuit.
This block will setup ADC reading function and return the reading value in every time step.
Previous : I2C Block
Next : DAC Block
Demo file : esp32_adc_demo.slx
This demo shows how to read ADC value and control a digital output pin according to the ADC value using ADC Block and Digital Output Block.
Connect the variable resistance output to the ADC pin(GPIO33) and connect the digital output pin (GPIO2) to a LED.
When the input voltage to the ADC pin is below 1.65V the LED will OFF and if it is above 1.65V the LED will turn ON.
Previous : I2C demo
Next : DAC demo
ตัว module อยู่ที่ amgApi.coreLib.analytics.advancedTable2
Quick start
const tableContainer = document.querySelector('.table-container')
tableController = await amgApi.coreLib.analytics.advancedTable2({
container: tableContainer,
data: [
['col1', 'col2', 'col3', 'col4'],
["c1r1", "c2r1", "c3r1", "1"],
["c1r2", "c2r2", "c3r2", "2"],
["c1r3", "c2r3", "c3r3", "3"],
["c1r4", "c2r4", "c3r4", "4"],
["c1r5", "c2r5", "c3r5", "5"],
["c1r6", "c2r6", "c3r6", "6"]
],
//columnLabel : ['customcol1', 'customcol2', 'customcol3', 'customcol4'],
//init : false
})
const tableContainer = document.querySelector('.table-container')
tableController = await amgApi.coreLib.analytics.advancedTable2({
container: tableContainer,
data: {
callback_getData: function (config, callback) {
amgApi.sqlite.all({
sql: `SELECT * FROM ${tableName} ${config.getFullSQL()}`
}, (getDataResponse) => {
callback(getDataResponse.rows)
})
},
callback_getColumn: function (columnName, callback) {
amgApi.sqlite.all({
sql: `SELECT ${columnName} FROM ${tableName}`
}, (getDataResponse) => {
callback(getDataResponse.rows)
})
},
callback_getCount: function name(config, callback) {
amgApi.sqlite.all({
sql: `SELECT COUNT(*) FROM ${tableName} ${config.getWhereSQL()} `
}, (countResponse) => {
const rowCount = Object.values(countResponse.rows[0])[0]
callback(rowCount)
})
}
}
})
const tableContainer = document.querySelector('.table-container')
tableController = await amgApi.coreLib.analytics.advancedTable2({
container: tableContainer,
data: [
['col1', 'col2', 'col3', 'col4'],
["c1r1", "c2r1", "c3r1", "1"],
["c1r2", "c2r2", "c3r2", "2"],
["c1r3", "c2r3", "c3r3", "3"],
["c1r4", "c2r4", "c3r4", "4"],
["c1r5", "c2r5", "c3r5", "5"],
["c1r6", "c2r6", "c3r6", "6"]
]
}, {
tableUI: {
checkbox: false,
sortFilter: false,
columnFilter: false,
responsive : false
}
})
const tableContainer = document.querySelector('.table-container')
tableController = await amgApi.coreLib.analytics.advancedTable2({
container: tableContainer,
data: [
['col1', 'col2', 'col3', 'col4'],
["c1r1", "c2r1", "c3r1", "1"],
["c1r2", "c2r2", "c3r2", "2"],
["c1r3", "c2r3", "c3r3", "3"],
["c1r4", "c2r4", "c3r4", "4"],
["c1r5", "c2r5", "c3r5", "5"],
["c1r6", "c2r6", "c3r6", "6"]
]
}, {
buttonBar: {
additionButton: [{
id: "add1",
side: "right",
getDOM: function () {
return $(`<button class="btn btn-secondary btn-sm " data-toggle="title" title="addition 1" >ADD!</button>`)[0]
}
}]
},
tableUI: {
checkbox: false,
sortFilter: false,
columnFilter: false,
responsive: false
}
})
const tableContainer = document.querySelector('.table-container')
tableController = await amgApi.coreLib.analytics.advancedTable2({
container: tableContainer,
data: [
['col1', 'col2', 'col3', 'col4'],
["c1r1", "c2r1", "c3r1", "1"],
["c1r2", "c2r2", "c3r2", "2"],
["c1r3", "c2r3", "c3r3", "3"],
["c1r4", "c2r4", "c3r4", "4"],
["c1r5", "c2r5", "c3r5", "5"],
["c1r6", "c2r6", "c3r6", "6"]
]
}, {
buttonBar: {
additionButton: [{
id: "add1",
side: "right",
getDOM: function () {
return $(`<button class="btn btn-secondary btn-sm " data-toggle="title"
title="addition 1" >
ADD!
</button>`)[0]
}
}]
},
tableUI: {
checkbox: false,
sortFilter: false,
columnFilter: false,
responsive: {
toggleIcon: {
expand: () => $(`<span ><i class="fas fa-plus"></i></span>`)[0]
},
visibleColIndex: [2],
collapse: {
container: () => $(`<div class="row bg-danger border-top pt-2 mt-2 ml-0" ></div>`)[0],
col: () => $(`<div class="col-6 bg-success font-weight-bold"></div>`)[0],
row: () => $(`<div class="col-6 bg-warning"></div>`)[0]
}
},
table: ({
preElement,
model
}) => {
return $('<div class="card "></div>')[0]
},
header: {
container: ({
preElement,
model
}) => {
return $('<div class="card-header text-center tableUI-sticky-top p-0 bg-success" ></div>')[0]
},
colContainer: ({
preElement,
data,
model
}) => {
return $('<div class="row "></div>')[0]
},
col: ({
preElement,
data,
colIndex,
model
}) => {
return $(`<div class="col border pt-2" >${data}</div>`)[0]
}
},
body: {
container: ({
preElement,
model
}) => {
return $('<div class="card-body bg-dark"></div>')[0]
},
rowContainer: ({
preElement,
data,
rowIndex,
model
}) => {
return $('<div class="row pb-4 bg-danger" ></div>')[0]
},
row: ({
preElement,
data,
rowIndex,
colIndex,
model
}) => {
const elementContainer = $(` <div class="col border rounded text-center px-3 py-2 bg-white text-dark align-middle"
style="width:100px;cursor:pointer;">
<span>${data}</span>
</div>`)
elementContainer.hover((e) => {
elementContainer.toggleClass(["bg-dark", "text-white"])
elementContainer.toggleClass(["bg-white", "text-dark"])
})
return elementContainer[0]
}
}
}
})
advancedTable2({}, {})
advancedTable2({
container,
data,
initialFilter
}, {})
[
['col1', 'col2', 'col3', 'col4'],
["c1r1", "c2r1", "c3r1", "1"],
["c1r2", "c2r2", "c3r2", "2"],
["c1r3", "c2r3", "c3r3", "3"],
["c1r4", "c2r4", "c3r4", "4"],
["c1r5", "c2r5", "c3r5", "5"],
["c1r6", "c2r6", "c3r6", "6"]
]
[
{col1: "c1r1",col2: "c2r1",col3: "c3r1",col4: "1"},
{col1: "c1r2",col2: "c2r2",col3: "c3r2",col4: "2"},
{col1: "c1r3",col2: "c2r3",col3: "c3r3",col4: "3"}
]
{
callback_getData: function (config, callback) {},
callback_getColumn: function (columnName, callback) {},
callback_getCount: function name(config, callback) {}
}
{
offset: <Number>,
rowPerPage: <Number>,
isFilterChange: <Boolean>,
getWhereSQL: <Function> ,
getFullSQL: <Function>,
filter: {
haveFilter: <Boolean>,
filterNumber: <Number>,
columnFilter: {
excludedValue: <Array[String]>,
SQL: <String>,
tester: <Function>,
haveFilter: <Boolean>
},
searchFilter: {
mode: <Number>,
modeString: <String>,
keyword: <Array[String]>,
SQL: <String>,
tester: <Function>,
haveFilter: <Boolean>
},
advFilter: {
setting: <Object>,
SQL: <String>,
tester: <Function>,
haveFilter: <Boolean>
}
},
sort: {
order: <String>,
mode: <String>,
colIndex: <Number>,
colName: <String>,
dateFormat: <Number>,
SQL: <String>,
sort: <Function>
isSort: <Boolean>,
}
}
callback_getData: function (config, callback) {
//fetch data
callback(data)
}
// columnName = "col2"
[
{col2: "c2r1"},
{col2: "c2r2"},
{col2: "c2r3"},
{col2: "c2r4"},
{col2: "c2r5"},
{col2: "c2r6"}
]
const tableName = "GW000001"
callback_getCount: function name(config, callback) {
amgApi.sqlite.all({
sql: `SELECT COUNT(*) FROM ${tableName} ${config.getWhereSQL()} `
}, (countResponse) => {
const rowCount = Object.values(countResponse.rows[0])[0]
callback(rowCount)
})
}
advancedTable2({}, {
buttonBar,
tableUI
})
additionButton: [{
id: "add1",
side: "right",
getDOM: function () {
return $(`<button class="btn btn-secondary btn-sm " data-toggle="title"title="addition 1" > ADD!</button>`)[0]
}
},
{
id: "add2",
side: "left",
getDOM: function () {
return $(`<button class="btn btn-success " data-toggle="title" title="addition 2" >create!</button>`)
.on('click', () => {
alert("create!")
})[0]
}
}
]
tableUI: {
checkbox: <Boolean>,
sortFilter: <Boolean>,
columnFilter: <Boolean>,
responsive: <Boolean || Object>,
table : <Function>,
header :<Object>,
body : <Object>
}
}
[["col1","col2"],["1","1"],["2","2"],["31","13"],["asf1","asf1"]]
// ตั้งค่าข้อมูลโดยตรง
setParameter("table","Data",{headers:["col1","col2"],data: [["1","1","1","1"],["2","2","12","12"],["31","13","31","31"],["asf1","asf1","ff1","1ff"]]})
// ตั้งค่าข้อมูลโดยดึงข้อมูลมาจากฐานข้อมูล แล้วเลือกแสดงเฉพาะคอลัมป์ที่ชื่อ "ชื่อเรือ"และ "ประเภทเรือ"
AmgCnt.SQLite.read.all({
sql: `SELECT * FROM "ข้อมูลตารางคนขอเข้าประเทศ2"`,
params: []
}, (res) => {
setParameter("table", "Data", {
headers: ["ชื่อเรือ", "ประเภทเรือ"],
data: res.rows
})
});
// ตั้งค่าข้อมูลดึงข้อมูลมาจากฐานข้อมูล แสดงทุกคอลัมป์ แต่มีการเปลี่ยนชื่อคอลัมป์ จาก "ชื่อเรือ" เป็น "header label ชื่อเรือ" และ "จังหวัด" เป็น "จาาหวัดด"
AmgCnt.SQLite.read.all({
sql: `SELECT * FROM "ข้อมูลตารางคนขอเข้าประเทศ2"`,
params: []
}, (res) => {
setParameter("table", "Data", {
headerLabels: [{colName: "ชื่อเรือ",label: "header label ชื่อเรือ"},
{colName: "จังหวัด",label: "จาาหวัดด"}],
data: res.rows
})
});
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Sqlite ชื่อ "ข้อมูลตารางคนขอเข้าประเทศ2"
// โดยทำการซ่อนคอลัมป์ชื่อ "ท่าเรือสุดท้ายก่อนเข้าไทย"
setParameter("table", "Data", {
tableName: "ข้อมูลตารางคนขอเข้าประเทศ2",
hiddenHeaders: ["ท่าเรือสุดท้ายก่อนเข้าไทย"]
})
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Sqlite ชื่อ "ข้อมูลตารางคนขอเข้าประเทศ2"
// โดยทำการซ่อนคอลัมป์ชื่อ "ท่าเรือสุดท้ายก่อนเข้าไทย" และเปลี่ยนชื่อคอลัมป์ "ชื่อเรือ" เป็น "GGG"
setParameter("table", "Data", {
tableName: "ข้อมูลตารางคนขอเข้าประเทศ2",
headerLabels: [{
colName: "ชื่อเรือ",
label : "GGG"
}],
hiddenHeaders: ["ท่าเรือสุดท้ายก่อนเข้าไทย"]
})
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Sqlite ชื่อ "ข้อมูลตารางคนขอเข้าประเทศ2"
// โดยทำการซ่อนคอลัมป์ชื่อ "ท่าเรือสุดท้ายก่อนเข้าไทย" และแสดงเฉพาะคอลัมป์ "ชื่อเรือ" ซึ่งจะถูกเปลี่ยนชื่อที่แสดงเป็น "ชื่อเรือ (custom)"
setParameter("table","Data",{tableName : "ข้อมูลตารางคนขอเข้าประเทศ2"
,headers:[{colName : "ชื่อเรือ",label:"ชื่อเรือ (custom)"}]
,hiddenHeaders:["ท่าเรือสุดท้ายก่อนเข้าไทย"]})
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Clickhouse ชื่อ "FARMER_ONE_AGRICULTUREAREA"
setParameter("table","Data",{tableName : "FARMER_ONE_AGRICULTUREAREA",database:"clickhouse"})
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Clickhouse ชื่อ "FARMER_ONE_AGRICULTUREAREA"
// โดยแสดงเฉพาะคอลัมป์ "AREA_CODE" และ "ZONE"
setParameter("table","Data",{tableName : "FARMER_ONE_AGRICULTUREAREA",database:"clickhouse",headers:["AREA_CODE","ZONE"]})
// ตั้งค่าข้อมูลให้ตารางดึงข้อมูลจาก ฐานข้อมูล Clickhouse ชื่อ "FARMER_ONE_AGRICULTUREAREA"
// โดยแสดงทุกคอลัมป์ แต่เปลี่ยนชื่อคอลัมป์ "AREA_CODE" เป็น "AAARRREEEEAAAA__CCOOODDEE" และเปลี่ยนชื่อคอลัมป์ "ZONE" เป็น "Zone header labels"
setParameter("table", "Data", {
tableName: "FARMER_ONE_AGRICULTUREAREA",
database: "clickhouse",
headerLabels: [{
colName: "AREA_CODE",
label: "AAARRREEEEAAAA__CCOOODDEE"
}, {
colName: "ZONE",
label: "Zone header labels"
}]
})
// กำหนดข้อมูลจาก Sqlite
setParameter("table", "Data", { sql: "SELECT * FROM ข้อมูลตารางคนขอเข้าประเทศ2 LEFT JOIN tool"})
// กำหนดข้อมูลจาก Clickhouse
setParameter("table","Data",{sql : `SELECT * FROM "FARMER_ONE_AGRICULTUREAREA" LIMIT 100`,database:"clickhouse"})
// กำหนดข้อมูลจาก Sqlite โดนกำหนดให้แสดงเฉพาะคอลัมป์ "ชื่อเรือ", "IMO" และ "เครื่องมือ"
setParameter("table", "Data", {
sql: "SELECT * FROM ข้อมูลตารางคนขอเข้าประเทศ2 LEFT JOIN tool",
headers: ["ชื่อเรือ", "IMO", "เครื่องมือ"]
})
{"data":[{"col1":"31","col2":"13"}],"headers":["col1","col2"]}
// เลือกติ๊กแถวที่ 1,2,4
setParameter("table","Selected",[1,2,4])
// รีเซิทการติ๊กทั้งหมด
setParameter("table","Selected",null)
// กำหนดให้แสดงข้อมูล 100 แถวต่อหน้า
setParameter("table","RowPerPage",100)
setParameter("table", "CellStyle", [{
// ถ้าจะเลือก checkbox ก็ colName : "_checkbox$"
// เลือกทั้งหมด ก็ colName : null หรือไม่ตั้งค่า colName
colName: "",
style: {
"text-align": "center",
"background-color": "wheat"
},
class: ["text-center", "bg-light"],
onCreateDOM: ({
preElement,
element,
data,
colName,
rowIndex,
colIndex,
allData,
}) => {
// preElement กับ element อันเดียวกัน แค่มีไว้ซัพพอร์ตตัวเก่าเฉยๆ
}
}])
setParameter("table", "CellStyle", {
// <table></table>
table: {
style: {
"text-align": "center",
"background-color": "wheat"
},
class: ["text-center", "bg-light"],
onCreateDOM: ({
preElement,
element,
}) => {}
},
header: {
// <thead></thead>
container: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
}) => {}
},
// <tr></tr>
colContainer: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
allData,
}) => {}
},
// <th></th>
col: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
colName,
colIndex,
allData,
}) => {}
},
},
body: {
// <tbody></tbody>
container: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
}) => {}
},
// <tr></tr>
rowContainer: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
allData,
rowIndex,
}) => {}
},
// <td></td>
row: {
style: {},
class: [],
onCreateDOM: ({
preElement,
element,
data,
colName,
rowIndex,
colIndex,
allData,
}) => {}
},
}
})
// ตั้งค่า style และ class ให้กับcell ในทุกคอลัมป์
setParameter("table", "CellStyle", [{
style: {
"text-align": "right",
"background-color": "wheat"
},
class: ["text-success"]
}])
// ตั้งค่า style และ class ให้กับcell ที่อยู่ภายใต้คอลัมป์ "col1"
setParameter("table", "CellStyle", [{
colName: "col1",
style: {
"text-align": "right",
"background-color": "wheat"
},
class: ["text-danger"],
}])
// ผสมการตั้งเฉพาะเจาะจง และการตั้งทั้งหมด
setParameter("table", "CellStyle", [
//ตั้งค่า style ให้ cell ภายใต้คอลัมป์ชื่อ "col1"
{
colName: "col1",
style: {"text-align": "left","background-color": "red"},
},
//ตั้งค่า style ให้ cell ภายใต้คอลัมป์ชื่อ "col2"
{
colName: "col2",
style: {"text-align": "center","background-color": "blue"},
},
// กำหนด class ให้ทุก cell ในทุกคอลัมป์
{
class: ["text-light"]
}
])
// ตั้งให้ทุกคอลัมป์มี class "text-success"
// และทำการเพิ่ม logic ว่าหากข้อมูลมีค่ามากกว่า 5 ให้ทำการแสดงข้อมูลใน Cell ว่า "Greater Than 5"
setParameter("table", "CellStyle", [{
class: ["text-success"],
onCreateDOM: ({
preElement,
element,
data,
colName,
rowIndex,
colIndex,
allData,
}) => {
if(data > 5){
$(element).text("Greater Than 5")
}
}
}])
// กำหนดหน้าตาของตารางทั้งหมด ในแต่ละส่วน ตามที่ต้องการ
setParameter("table", "CellStyle", {
// <table></table>
table: {
class: ["table-hover", "text-left"],
},
header: {
// <thead></thead>
container: {
onCreateDOM: ({
preElement,
element,
}) => {
return $('<thead ></thead>')[0]
}
},
col: {
style: {
"box-shadow": "none",
"border-top": "none",
"background-color": "white"
},
class: ["lead"],
},
}
})
setParameter("table","Update")
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| MISO pin | 0 to 33 | Select MISO pin |
| MOSI pin | 0 to 33 | Select MOSI pin |
| SCK pin | 0 to 33 | Select SCK pin |
| CS pin | 0 to 33 | Select CS pin |
| SSID | Enter preferred WiFi SSID. | |
| Password | Enter preferred WiFi password | |
| IP Address | Enter the preferred IP address | |
| Max connections | Enter the maximum number of connections allowed to be connected to the WiFi network. | |
| Output User Active Status | Check--Uncheck | This parameter is used to check whether the user is active on the client side or not. To use this feature, client should be configured accordingly using Aimagin Connect. |
This block can be used to convert an ESP32 to a server that could host a web application created using Aimagin Connect.
Create embedded web application with Aimagin Connect
Previous : SD Card Append Block
Next : SQLite Retrieve Data
Welcome to Aimagin support portal.
There are two main public sources to get information and assistance for Aimagin's products and services, namely wiki and forum.
aMG 4-20mA to WiFi Data Logger User Manual
This user manual is for aMG 4-20 mA to WiFi Data Logger with the latest firmware version r3s.21.02c .
Visit aMG 4-20 mA to WiFi Data Logger product page page to purchase the product.
Figure 1-1 : aMG 4–20 mA to WIFI Data Logger
aMG 4-20 mA to WiFi Data Logger is a device that can read up-to 4 channels of 4-20 mA data every 1 second. The data can be encrypted and sent to your own database server securely via WiFi, with 7-years-worth of in-device backup storage. Therefore, you will always have critical information, to the finest detail, stored securely and redundantly both in your own server and in the device.
Figure 1-2 : Basic Concept of aMG 4–20 mA to WIFI Data Logger
Installation and usage are simple. No need for data link cabling. No need to collect data on-the-spot. No need to worry about data security and privacy. Just setup your own database server, connect the device to a common WiFi network, and wait for the data to arrive in your database. Most suitable for customer with basic IT knowledge to set up your own database server (free example source code available for our customers).
Figure 1-3 : aMG 4–20 mA to WIFI Data Logger work diagram
Figure 2-1 : aMG 4–20 mA to WIFI Data Logger Size
According to the hardware specifications, aMG 4-20 mA to WiFi Data Logger has the minimum requirements as following:
Figure 4-1 : Hardware Components
Table 4-1 : aMG 4-20 mA to WIFI Data Logger's Components
| Component | Functions | Description |
| A | Power supply VCC | Port, to connect to the power supply VCC (9 – 24 V). |
| B | Power supply GND | Ports, to connect to the power supply ground. |
| C | Input channels | Ports, to connect to sensors, support up to 4 sensors. |
| D | Router antenna | WiFi router antenna. |
| E | LED indicator | A power status indicator and operating status indicator (see Operating LED Indicator). Other two LEDs are not available. |
| F | Antenna connector | Antenna input connector. |
| G | Enclosure locks | Case lock. It can be opened to insert the micro SD card or other internal components. |
Figure 4-2 : Operating LED Indicator
As mentioned in previous section, there're only 2 LED available as shown in the figure above. The power status is indicated by the yellow LED, while the green LED shows the status of the operating condition with blink in different frequency. The meaning of each LED freequency is defined as following:
Figure 4-3 : LED Blink
Table 4-2 : aMG 4-20 mA to WIFI Data Logger LED Status
| No. | Operation Mode | Condition | LED Indication |
| 1 | Access Point (AP) /Configuration Mode | available for connection from a user, no connection or trying to connect |  blink 1 Hz |
| 2 | Access Point (AP) /Configuration Mode | user connected successfully |  solid |
| 3 | Station Mode (STA) /Running Mode | trying to connect to a WIFI access point |  blink 5Hz |
| 4 | Station Mode (STA) /Running Mode | successfully connected to a WIFI access point |  2 fast blink and 1 sec OFF |
Components, refer to the Figure 4-1
Tips: Scan QR Code on the device for more information or any helps.
aMG 4-20 mA to WIFI Data Logger has two operation mode which is Configuration Mode and Running Mode.
Setting the aMG 4-20 mA to WIFI Data Logger can be done easily in the configuration mode via web-application by using a desktop computer or mobile phone.
Step 1 Connect the power supply to aMG 4-20 mA to WIFI Data Logger.
Step 2 Disconnect WIFI on your desktop and connect your desktop or mobile phone to the device through WIFI connection by selecting the device name 4-20mA-<UID> in the WIFI setting as figure below. The password is 12345678.
Figure 5-1 : Connecting the device
Note: This step shall be done within 60 seconds after connecting the device to power supply. After 60 second without connection, it will work as running mode automatically. To attempt to configuration mode, you need to disconnect the power supply and re-connect again. Then the device will switch to configuration mode again.
Step 3 Open a web browser, then go to the URL:
192.168.10.10The Aimagin Analytics login page will appear as figure below.
Figure 5-2 : Aimagin Analytic login page
Step 4 Login by using username as admin with the password 1234 . After logging in, the configuration page will pop up. The device is in the configuration mode now. User can see the configuration tab at the left as following:
Figure 5-3 : Configuration Tab
Before using, user need to select the WiFi access point for the device by filling the information as shown below.
Figure 5-4 : WiFi Configuration
Figure 5-5 : Update complete message
Note: For IP setting, Dynamic is recommended. However, it depends on user security policy.
In this tab, user can do Soft Reset by clicking Reset button.
Figure 5-6 : Soft Reset
After clicking Soft Reset button, there is a pop up message for confirmation as below figure, then click OK.
Figure 5-7 : Soft Reset Confirmation Message
Once the device is soft reset completely, a message appears as following figure.
Figure 5-8 : Soft Reset Complete
For more information, see Soft Reset
Note: Soft reset function will lose all configuration data, make sure that user backup the data before doing reset.
In this menu, user can find the Device UID and its Firmware version here. In additions user can set the sample time of channel the target server to send out data to the database, and JSON format parameters as a default data format.
Figure 5-6 : System Configuration
Figure 5-7 : Turn On Encryption Data
To save all setting in this page, click on Submit, then the update status message will pop up as figure 5-5.
This menu is for configuring the input/output signal conversion.
Figure 5-8 : 4-20 mA Configuration
Once user provide all information above, to save all setting in this page, click on Submit, then the update status message will pop up as figure 5-5.
To understand the concept of 4-20 mA Signal Conversion, see the figure below:
Figure 5-9 : 4-20 mA Conversion
Once the new firmware available, user can purchase for the firmware to upgrade the device via the Firmware upgrade section.
Figure 5-10 : Firmware Upgrade
When user get the new firmware (.bin file), just follow the step below:
After firmware upgraded, user needs to download new file (.7z) to replace all file in micro SD card.
Note: In case of firmware upgrade, both configuration data and sensor data will be lost. Make sure that user back-up the data before upgrading.
This menu to show the data display for each channel in real time according to user settings.
Figure 5-11 : Data Display
This feature is for downloading the sensor data which collected by the device. There are two options to download, i.e. database and log file format.
Figure 5-12 : Files Download
Figure 5-13 : User Management
In Users menu, user will find user list and their log-in history to the device. You can manage users and their permission to access device configuration under this menu.
Figure 5-14 : To create user
To exit the configuration mode or start the device in running mode:
Figure 5-15 : Log in Profile tab
Click on the admin login profile at the right corner of the web page, then click log out.
Note: If there is no active in configuration mode for 60 seconds, it will end the configuration mode and start running mode automatically.
When turn on the aMG 4-20 mA to WIFI Data Logger, it will run in Configuration mode automatically. To end up the configuration mode and switch to Running mode respectively.
In Running mode, aMG 4-20 mA to WIFI Data Logger will use the predefine configuration parameters according to the user setting. After the setup, the device will perform the following steps:
This type of reset is to reset only the configuration setting, i.e. the configuration data will be erased while the collected data from sensor still remain.
The factory reset is to reset all data stored in the device, both confuguration data and collected data. Therefore, user need to backup log data before doing factory reset.
For aMG 4-20 mA to WIFI Data Logger, Factory Reset can be done by formatting the micro SD card then copy the server inintial file to the micro SD card which is the same method of Preparing micro SD Card.
This feature is for checking whether the device still work and collect data properly during running mode. In case the long length sample time, using this heartbeat feature, user don't need to wait until the next data arrives according to the sample time for each channel because this feature will allow the device collect data earlier than the actual sample time, i.e. the heartbeat feature will let the device to collect sensor data according to the Heartbeat sample time, which shall be less than the sample time for each input channel. If the device works properly, user will see the data before sampling period.
Figure 6-1 : Heartbeat feature concept
Encryption is a process of converting the valuable data or plaintext into an alternative form of data which is called as a ciphertext . It is used to secure the sensitive data when sending from one device to another. Encryption is performed using an encryption key and that key can be accessible for authorized persons. The ciphertext can only be converted to the plaintext using the same encryption key which is used to encrypt the data. There are different types of encryption methods to encrypt and decrypt the data.
Figure 6-2 : Data Encryption and Decryption
aMG 4-20 mA to WIFI Data Logger has the capability to encrypt the data in AES CBC method. It is using an encryption key with the size of 256 bits (32 bytes). This 32 byte key is dynamically changed from time to time and it is formed with the combination of the time when sending the data and a static key (22 bytes). That static key should be specified in the system configuration page of configuration mode. In the encryption process, the default JSON package converted to a ciphertext and put it in to another JSON package with datetime, organization id and sent it to the database server. The sample JSON package after the encryption will be as below.
{
"id":"xxxxxxxx",
"encrypt_data":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
"datetime":"xxxxxxxxxx"
}
To remove micro SD card, see the following steps:
Step 1 Open the case by unlocking the enclosure lock, see component G, Figure 4-1.
Step 2 Lift the FiO Glide ESP32 board (the upper board) from the main board as shown in figure 6-3.
Figure 6-3 : Removal micro SD card
Step 3 micro SD card is installed at the back of FiO Glide ESP32 board. Push the micro SD card to remove it.
Once user wants to replace the micro SD card with the new one, perform the following steps:
Step 1 Remove the old micro SD card, see Removal and installation SD Card.
Step 2 Format the new micro SD card using FAT32 file system.
Step 3 Copy all files and folders from the old SD card as shown in the figure below to the new micro SD card. If not all files and folders appear as shown in the figure, try view hidden files in Windows Explorer setting.
Figure 6-4 : Preparing micro SD card
Step 4 Insert the new micro SD card into the device, see Removal and installation of micro SD Card.
The SQLite database in the micro SD card serves as a backup and could be accessed anytime by following the steps below.
Step 1 Remove the micro SD card from the device as described in Removal and installation of micro SD card.
Step 2 Attach the micro SD card to a micro SD card reader and connect it to the computer.
Note: make sure that the micro SD card reader/adaptor is set as unlock when it is inserted into the computer, otherwise user cannot change or manage any files in the micro SD card.
Step 3 Download and install DB Browser for SQLite
Step 4 Open DB Browser for SQLite.
Figure 6-5 : SQLite database
Step 5 Click Open Database . Browse and select the .../systems/system1/database.db file in the micro SD card.
Figure 6-6 : Browse database file
Step 6 Click the Browse Data tab and select the Table : data_table. Here you can find the saved data from the device.
Figure 6-7 : Data table
Step 7 To use an SQL query to filter data, click Execute SQL tab, type the command and click run icon
Figure 6-8 : Filter data
Note: The data stored in micro SD card are always stored with UNIX timestamp. To analyze data in human-readable date time format, see How to convert UNIX format data to ISO format.
Raw data is stored in data_table table of the database.db, which can be exported as a CSV file using the following steps:
Step 1 Open the * database.db * file with DB Browser for SQLite.
Step 2 Select File->Export->Table(s) as CSV file...
Step 3 Select the table: * data_table * and click * Save * .
Figure 6-9 : Export CSV file
Step 4 A window will pop up where you could select the name and location of the CSV file to be saved.
Step 5 User could use Microsoft Excel or any other similar software to open the CSV file.
The JSON format of the data which sends from the device to the database server is as below.
{
"mac":"xxxxxxxxxxxx",
"id":"xxxxxxxx",
"table":"xxxxxx",
"column":[
"datetime",
"CH1_raw",
"CH1_conv",
"CH2_raw",
"CH2_conv",
"CH3_raw",
"CH3_conv",
"CH4_raw",
"CH4_conv"
],
"rows":[
{
"datetime":"xxxxxxxxxx",
"CH1_raw":0.000,
"CH1_conv":0.000,
"CH2_raw":0.000,
"CH2_conv":0.000,
"CH3_raw":0.000,
"CH3_conv":0.000,
"CH4_raw":0.000,
"CH4_conv":0.000
}
]
}
The timestamp of the data stored in micro SD card is in UNIX format for efficiency. To easily analyze the data the user could use the DB Browser for SQLite.
Step 1 Open the micro SD card using windows explorer and copy the .../systems/system1/database.db file in the micro SD card to a known location. This step is taken as a precaution to not alter the actual data table in the micro SD card as it could lead to device malfunction.
Step 2 Download and install DB Browser for SQLite
Step 3 Open DB Browser for SQLite.
Step 4 Click Open Database . Browse and select the database.db file saved at the known location during Step 1 .
Figure 6-10 : SQLite database
Step 5 Click the Browse Data tab and select the Table : data_table. Here you can find the saved data from the device.
Figure 6-11 : Data table
Step 6 Go to Execute SQL tab. The user can now use any SQLite query to filter the data in the table as needed.
Here are two examples on handling UNIX time format.
Step 7 Create an additional column next to datetime column called date_iso which corresponds to the datetime in ISO format of each UNIX format timestamp.
SELECT datetime,
datetime(datetime, 'unixepoch', 'localtime')
AS date_iso,
CH1_raw,
CH1_conv,
CH2_raw,
CH2_conv,
CH3_raw,
CH3_conv,
CH4_raw,
CH4_conv
FROM data_table
Figure 6-11 : UNIX format data
Step 8 Filter out rows of sensor data which are in between two timestamps, specifying the date and time in ISO format.
select timestamp,CH1_raw
from data_table
where datetime(timestamp, 'unixepoch', 'localtime')
between '2020-10-22 18:15:30' and '2020-10-22 18:18:30';
This section provides information regarding testing sending data from aMG 4-20 mA to WIFI Data Logger to a database server.
The purpose of the test is to ensure that the device can transfer the collected data to a database server properly. User can test the device as the following steps:
Step 1 Since the database server is required, user needs to register for a database which shall be the target server for the device via the following URL: http://testiot.aimagin.com/register
The register page will be loaded as shown in Figure 6-12.
Figure 6-12 : Register Page
Step 2 Select data encryption option, then provide your Organization ID, First Name, Last Name, Email, and MAC Address (12-digit UID of the aMG 4-20mA to WIFI Data Logger)
Note: User can add MAC Address for many devices at once.
Step 3 Click on Submit, the Register Success page will be loaded. The page contains some necessary configuration data, i.e. Target Server domain, Secret Key, Encryption Key (In case user select encryption option), and Table name as shown below.
Figure 6-13 : Register Success
Step 4 Go to system configuration and set configuration data according to the data in Register Success page, then click on Start Test. The data table will appear as below.
Figure 6-14 : Data Table
Step 5 To see data display of each device, user can click on Info in the row of the device, then the data display will be shown as figure below. And to go back to the data table page, click on Back
Figure 6-15 : Data Display for testing
Step 6 To finish testing, just click on Finish Test in the data table page. The page will appears as below.
Figure 6-16 : Finish Test page
Note: If user wants to test again, user can click on Click Here to go back to the test.
In case the user does not have a personal server, Google Sheets can be used as a server to log the data sent from aMG 4-20 mA to WIFI Data Logger. The process is as follows.
Step 1 Sign in to your google account and open a new google sheet.
Step 2 Insert the following column names to cells 1A-1I.
Step 3 Change the sheet name to test_table (The user can select any name preferred. Make sure there are no space in the sheet name.)
Step 4 Change the spread sheet name to 4-20mA_Google_Server. (The user can use any name preferred. Make sure there are no space in the spread sheet name.)
Figure 7-1 : Google Spreadsheet
Step 5 In the Menu Bar go to Tools->Script Editor. This will open up a new tab with an editor to write your Google Script
Step 6 Give the project name as 4-20mA_Google_Script. (The user can use any name preferred. Make sure there are no space in the project name.)
Step 7 Copy and Paste the following code to the editor. Make sure to change the user_sheet variable to that used in Step 3.
// IMPORTANT: Change the sheet name accordingly
var user_sheet = "test_table"
function doGet(e) {
var ss = SpreadsheetApp.getActive();
var sheet = ss.getSheetByName(user_sheet);
var headers = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0];
var lastRow = sheet.getLastRow();
var cell = sheet.getRange('a1');
var col = 0;
var d = new Date();
for (i in headers){
val = e.parameter[headers[i]];
cell.offset(lastRow, col).setValue(val);
col++;
}
return ContentService.createHtmlOutput("Success");
}
function updateSheet(rows) {
var ss = SpreadsheetApp.getActive();
var sheet = ss.getSheetByName(user_sheet);
var column = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0];
for(var i=0;i<rows.length;i++) {
var d = [];
for(var j=0;j<column.length;j++) {
d.push(rows[i][column[j]]);
}
sheet.appendRow(d)
}
}
function doPost(e) {
let data = JSON.parse(e.postData.contents);
Logger.log(data);
updateSheet(data.rows);
return ContentService.createHtmlOutput("Success");
}
Step 8 In the Menu Bar go to Publish->Deploy as web app...
Step 9 In the pop-up window make sure the correct settings are set and click Deploy.
Figure 7-2 : Google Spreadsheet (2)
Step 10 In the pop-up Authorization required, select * Review Permissions*
Figure 7-3 : Google Spreadsheet (3)
Step 11 Next you might be prompted with a new window to sign in to your google account. When you sign-in it will re-direct to a warning page. Here go to Advanced and click Go to 4-20mA_Google_Script (unsafe).
Figure 7-4 : Google Spreadsheet (4)
Step 12 Then click Allow access.
Figure 7-5 : Google Spreadsheet (5)
Step 13 The new window will close and user will be prompted with a pop-up. Copy and Paste the Current web app URL to a known location. This contains the secret key to the Google Sheet you created. Therefore keep this URL safe. Click OK. The URL will look something like this.
https://script.google.com/macros/s/ _{your secret key without curly brackets}_ /exec
Step 14 Now your Google Sheet is a server waiting for GET or POST requests from the client. To test the process simply type the following URL on any browser with a computer connect to internet. This should print some values to the google sheet you created.
https://script.google.com/macros/s/ _{your secret key without curly brackets}_ /exec?id=test_table&datetime=601235&CH1_raw=0&CH1_conv=0&CH2_raw=1&CH2_conv=1&CH3_raw=2&CH3_conv=2&CH4_raw=3&CH4_conv=3
Figure 7-6 : Google Spreadsheet (6)
Step 15 Now power on the aMG 4-20 mA to WIFI Data Logger and sign in during the Configuration Mode
Step 16 Set the System Configuration on setting page by adding the Domain/URL and the Secret Key and Save changes, see System Configuration.
Figure 7-10 : Setting System Configuration
Step 17 Once the device go into running Mode, it will start logging data to the created google sheet.
This is a PHP example for creating a web service to store data submitted from client to MySQL database.
Client posts data to server at URL:
127.0.0.1:8080/[work directory]\
Note: This url is only for local testing. http://l127.0.0.1:8080 should be changed to correct URL.).
The data is in JSON format as shown below:
{
"id": "esp32",
"table": "test_table",
"column": [
"c1",
"c2"
],
"rows": [
{
"c1": 1,
"c2": 982
},
{
"c1": 2,
"c2": 985
},
{
"c1": 3,
"c2": 988
}
]
}
Where:
id is organization ID;
table is table name;
column is number of data column in any row.
rows is each data to be recorded into the table.
In index.php:
To receive and decode posted data to query string example:
<?php
# databaseconnect
$servername = "localhost:3306";
$username = "root";
$password = "test1234";
$dbname = "test_db";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
header('Access-Control-Allow-Origin: *');
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if ($_GET["id"] == "Du81QXQGE6uswzRxXUnagKarauJL80w6/insert") {
# input json
$inputJSON = file_get_contents('php://input');
$data = json_decode($inputJSON, TRUE); //convert JSON into array
# convert data
$column = "";
$values = [];
$values_string = "";
$column = implode(", ", $data['column']);
foreach ($data['rows'] as $row) {
$r = "";
foreach ($data['column'] as $i => $col) {
if ($i + 1 === count($data['column'])) {
$r .= '"' . $row[$col] . '")';
array_push($values, $r);
} else if ($i === 0) {
$r .= '("' . $row[$col] . '",';
} else {
$r .= '"' . $row[$col] . '",';
}
}
}
$values_string = implode(", ", $values);
# query sql
$sql = 'INSERT INTO ' . $data['table'] . ' (' . $column . ') VALUES ' . $values_string;
// print_r($sql);
# insert to db mysql
if (count((array)$data['rows'][0]) > 0) {
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
}
}
}
$conn->close();
<?php
# databaseconnect
$servername = "localhost:3306";
$username = "root";
$password = "test1234";
$dbname = "test_db";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
//echo 'Connected successfully';
header('Access-Control-Allow-Origin: *');
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if ($_GET["id"] == "Du81QXQGE6uswzRxXUnagKarauJL80w6/insert") {
# input json
$inputJSON = file_get_contents('php://input');
$data = json_decode($inputJSON, TRUE); //convert JSON into array
# convert data
$column = "";
$values = [];
$values_string = "";
$new_str = substr($data['table'], 11);
array_push($data['column'], "hw_id");
if (count((array)$data['rows'][0]) > 0) {
for ($i = 0; $i < count($data['rows']); $i++) {
$data['rows'][$i]['hw_id'] = $new_str;
}
}
$column = implode(", ", $data['column']);
foreach ($data['rows'] as $row) {
$r = "";
foreach ($data['column'] as $i => $col) {
if ($i + 1 === count($data['column'])) {
$r .= '"' . $row[$col] . '")';
array_push($values, $r);
} else if ($i === 0) {
$r .= '("' . $row[$col] . '",';
} else {
$r .= '"' . $row[$col] . '",';
}
}
}
$values_string = implode(", ", $values);
# query sql
$sql = 'INSERT INTO ' . substr($data['table'], 0, 10) . ' (' . $column . ') VALUES ' . $values_string;
# insert to db mysql
if (count((array)$data['rows'][0]) > 0) {
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
}
}
}
$conn->close();
. htaccess for rewrite URL
RewriteEngine On
RewriteBase /esp32_multi
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?id=$1 [L,QSA]
This is NodeJS example for creating a web service to store data submitted from client to SQLite database.
Client posts data to server at URL:
http://localhost:8080/U4tfcUMqnwMxWrGLwNZKdWDMx2XGYfGgb2LzpZJdY6dVdQQ9ReJ377aJEBht6Rkk/insert
Note: This url is only for local testing. http://localhost:8080 shall be replaced to correct URL.
The data is in JSON format as shown below:
{
"id": "esp32",
"table": "test_table",
"column": [
"c1",
"c2"
],
"rows": [
{
"c1": 1,
"c2": 982
},
{
"c1": 2,
"c2": 985
},
{
"c1": 3,
"c2": 988
}
]
}
id is organization ID
table is table name
column is number of data column in any row.
rows is each data to be recorded into the table
This setup method, NodeJS is required.
To download and install NodeJS, see NodeJS
To run this code:
1. extract web_service.zip
2. install sqlite3 using command: npm install sqlite3
3. start server using command: node server.js
To keep this web service running on server:
1. install pm2 on server using command npm install pm2
2. start the process using command pm2 start server.js
In web_server.zip,
./esp32/db/database.db
./server.js
In case the organization ID is parent folder that contains the SQLite database named database.db . Server.js is nodeJS code for creating web service.
In server.js:
References:const http = require('http'); const url = require('url'); const sqlite3 = require('sqlite3').verbose(); http.createServer(function(req, res){ var qpath = url.parse(req.url, true).pathname; var data = ""; res.setHeader("Access-Control-Allow-Origin", '*'); req.on('data', chunk=> { data += chunk; }).on('end', ()=> { data = JSON.parse(data); if (qpath == '/U4tfcUMqnwMxWrGLwNZKdWDMx2XGYfGgb2LzpZJdY6dVdQQ9ReJ377aJEBht6Rkk/insert') { var params = [], values = []; data.rows.forEach(function(row) { params = params.concat(data.column.map(d=>row[d])); values = values.concat('('+data.column.map(d=>'?')+')'); }); var db = new sqlite3.Database("./"+data.id+"/db/database.db"); db.run(`INSERT INTO ${data.table} (${data.column}) VALUES ${values}`, params, (err)=>{ if(err) { res.write("Failture: "+err.message); } else { res.write("Success"); } res.end(); }); db.close(); } else { res.write(null); res.end(); } }); }).listen(8080);
This tutorial will demonstrate how to log data from ESP32 on a google sheet using the Waijung2 block-set.
Log in to your Google account and open a blank Google Spread Sheet.
Now the google sheets needs to be published as a web application which will be listening to web requests. For that we use Google Script. Now go to Tools -> Script editor. This will open up a new window to write the script. Copy and paste the code in the GScriptCode.txt file to the Google Script editor. Save the script with a preferred name. (Example: ESP32_Data_Log_Script).
Click here to find more information regarding Google Script.
Go to Publish -> Deploy as web app.
In the pop-up window make the configurations as shown in the picture.
Click Deploy.
From the pop-up window click Review Permissions. This will open up a new windows to sign in to your Google account.
After Signing in the page in the new window will re-direct to a warning page. There click Advanced and click Go to yourscriptname (unsafe).
Then the page in the new window will direct to another page where you will be asked for permission to run the app. Click Allow .
Copy and save the URL and click OK .
Your URL will look something like this:
https://script.google.com/macros/s/{yourkey}/exec
The yourkey is a unique key for that specific Google Sheet you created. Therefore do not share this key.
To test the server open a browser and enter the URL below.
https://script.google.com/macros/s/{your-key}/exec?id=Sensor_Data&Sensor1=100&Sensor2=100
If everything is correct, the word 'success' will be shown on your web page.
Now if you go back to your google sheet you will be able to see your data (sensor1 = 100, sensor2 = 100) been logged.
Congratulations you have successfully setup your Google sheet as the server!
Save and upload the code to the ESP32 board.
In this example, as sensors a constant block and a counter block is used to simulate the program. You can replace them with your sensor readings.
After uploading you will be able to see the sensor values being updated every 5 seconds to the Google Sheet.
Previous : HTTP Server demo
Next : How to connect a hardware to a Wi-Fi Access Point
Download the tutorial files: moving_object_tracking_tutorial.7z (Note: Among other things you will need to have the Computer Vision System Toolbox to run these demos)
This tutorial aims at demonstrating how to use image processing to track a moving object.
We make these tutorials for use to test the up coming camera and image processing utility blockset for Waijung 13.11a, to be release in Nov 2013. So stay tuned…
This tutorial follows the Student Dave’s Tutorials! Basic Image Processing with Matlab, but in Simulink instead of Matlab m-file implementation.
We were able to watch just the 2 video tutorials by Student Dave’s (items 2 and 3 below) and implement this in Simulink in just 1 day without any prior image processing knowledge.
So the explanation is extremely comprehensive, easy-to-understand and, hence, highly recommended.
The Student Dave’s Tutorials! site also contains other simple-to-understand tutorials on such topics as Kalman filtering, Extended Kalman filtering, and Particle filtering.
If you have time, visit the Student Dave’s Tutorials! site and help make some donations to fuel these great tutorials with coffee and Ramen. :)
The followings summarize resources related only to this basic image processing tutorial.
The followings summarize steps for moving object tracking:
Note: we used MakeAVI (http://makeavi.sourceforge.net/) to convert the original video file to individual images.
The followings display different Simulink model files for studying the algorithm progressively.
1) ex01_object_tracking_static_demo.mdl
Test moving object detection algorithm using static picture.
Tracking result
2) ex02_object_tracking_dynamic_demo.mdl
Track moving object from video.
Simulation results
3) ex03_object_tracking_offline_demo.mdl
The same as ex02_object_tracking_dynamic_demo above except that the background image is computed by averaging images from the first few seconds.
See this article http://aimagin.com/blog/real-time-moving-object-tracking-stm32f4-image-processing-algorithms/ for a real-time system implementation.
This demo showing an example of implementation the run-time firmware upgrade, mostly used in the product that need features update, bugs fix at end user or located on network. Waijung Blockset provide blocks function to develop this features, demonstration here tested with STM32F4 Target. The demo files are available for commercial and academic licensed users only.
IAP communication is data channel for receiving the new upgrade ROM. Depending on implementation in main program (user application) running, it can be UART, CAN or other.
Sector B and C can be be validated by CRC32 and firmware signature, by using binary converter software to embedded these value into binary for upgrade ROM
Polynomial: 0x4C11DB7
Initial value: 0xFFFFFFFF
const unsigned int crc_table[256] = {
0x00000000,0x04C11DB7,0x09823B6E,0x0D4326D9,0x130476DC,0x17C56B6B,0x1A864DB2,0x1E475005,
0x2608EDB8,0x22C9F00F,0x2F8AD6D6,0x2B4BCB61,0x350C9B64,0x31CD86D3,0x3C8EA00A,0x384FBDBD,
0x4C11DB70,0x48D0C6C7,0x4593E01E,0x4152FDA9,0x5F15ADAC,0x5BD4B01B,0x569796C2,0x52568B75,
0x6A1936C8,0x6ED82B7F,0x639B0DA6,0x675A1011,0x791D4014,0x7DDC5DA3,0x709F7B7A,0x745E66CD,
0x9823B6E0,0x9CE2AB57,0x91A18D8E,0x95609039,0x8B27C03C,0x8FE6DD8B,0x82A5FB52,0x8664E6E5,
0xBE2B5B58,0xBAEA46EF,0xB7A96036,0xB3687D81,0xAD2F2D84,0xA9EE3033,0xA4AD16EA,0xA06C0B5D,
0xD4326D90,0xD0F37027,0xDDB056FE,0xD9714B49,0xC7361B4C,0xC3F706FB,0xCEB42022,0xCA753D95,
0xF23A8028,0xF6FB9D9F,0xFBB8BB46,0xFF79A6F1,0xE13EF6F4,0xE5FFEB43,0xE8BCCD9A,0xEC7DD02D,
0x34867077,0x30476DC0,0x3D044B19,0x39C556AE,0x278206AB,0x23431B1C,0x2E003DC5,0x2AC12072,
0x128E9DCF,0x164F8078,0x1B0CA6A1,0x1FCDBB16,0x018AEB13,0x054BF6A4,0x0808D07D,0x0CC9CDCA,
0x7897AB07,0x7C56B6B0,0x71159069,0x75D48DDE,0x6B93DDDB,0x6F52C06C,0x6211E6B5,0x66D0FB02,
0x5E9F46BF,0x5A5E5B08,0x571D7DD1,0x53DC6066,0x4D9B3063,0x495A2DD4,0x44190B0D,0x40D816BA,
0xACA5C697,0xA864DB20,0xA527FDF9,0xA1E6E04E,0xBFA1B04B,0xBB60ADFC,0xB6238B25,0xB2E29692,
0x8AAD2B2F,0x8E6C3698,0x832F1041,0x87EE0DF6,0x99A95DF3,0x9D684044,0x902B669D,0x94EA7B2A,
0xE0B41DE7,0xE4750050,0xE9362689,0xEDF73B3E,0xF3B06B3B,0xF771768C,0xFA325055,0xFEF34DE2,
0xC6BCF05F,0xC27DEDE8,0xCF3ECB31,0xCBFFD686,0xD5B88683,0xD1799B34,0xDC3ABDED,0xD8FBA05A,
0x690CE0EE,0x6DCDFD59,0x608EDB80,0x644FC637,0x7A089632,0x7EC98B85,0x738AAD5C,0x774BB0EB,
0x4F040D56,0x4BC510E1,0x46863638,0x42472B8F,0x5C007B8A,0x58C1663D,0x558240E4,0x51435D53,
0x251D3B9E,0x21DC2629,0x2C9F00F0,0x285E1D47,0x36194D42,0x32D850F5,0x3F9B762C,0x3B5A6B9B,
0x0315D626,0x07D4CB91,0x0A97ED48,0x0E56F0FF,0x1011A0FA,0x14D0BD4D,0x19939B94,0x1D528623,
0xF12F560E,0xF5EE4BB9,0xF8AD6D60,0xFC6C70D7,0xE22B20D2,0xE6EA3D65,0xEBA91BBC,0xEF68060B,
0xD727BBB6,0xD3E6A601,0xDEA580D8,0xDA649D6F,0xC423CD6A,0xC0E2D0DD,0xCDA1F604,0xC960EBB3,
0xBD3E8D7E,0xB9FF90C9,0xB4BCB610,0xB07DABA7,0xAE3AFBA2,0xAAFBE615,0xA7B8C0CC,0xA379DD7B,
0x9B3660C6,0x9FF77D71,0x92B45BA8,0x9675461F,0x8832161A,0x8CF30BAD,0x81B02D74,0x857130C3,
0x5D8A9099,0x594B8D2E,0x5408ABF7,0x50C9B640,0x4E8EE645,0x4A4FFBF2,0x470CDD2B,0x43CDC09C,
0x7B827D21,0x7F436096,0x7200464F,0x76C15BF8,0x68860BFD,0x6C47164A,0x61043093,0x65C52D24,
0x119B4BE9,0x155A565E,0x18197087,0x1CD86D30,0x029F3D35,0x065E2082,0x0B1D065B,0x0FDC1BEC,
0x3793A651,0x3352BBE6,0x3E119D3F,0x3AD08088,0x2497D08D,0x2056CD3A,0x2D15EBE3,0x29D4F654,
0xC5A92679,0xC1683BCE,0xCC2B1D17,0xC8EA00A0,0xD6AD50A5,0xD26C4D12,0xDF2F6BCB,0xDBEE767C,
0xE3A1CBC1,0xE760D676,0xEA23F0AF,0xEEE2ED18,0xF0A5BD1D,0xF464A0AA,0xF9278673,0xFDE69BC4,
0x89B8FD09,0x8D79E0BE,0x803AC667,0x84FBDBD0,0x9ABC8BD5,0x9E7D9662,0x933EB0BB,0x97FFAD0C,
0xAFB010B1,0xAB710D06,0xA6322BDF,0xA2F33668,0xBCB4666D,0xB8757BDA,0xB5365D03,0xB1F740B4
};
unsigned int crc32_update(unsigned int initial, const unsigned int *data, int count)
{
int i;
unsigned int accum = initial;
for (i=0; i<count; i++) {
accum = (accum<< 8)^ crc_table[((accum>> 24)^ (data[i]>> 24))& 0xFF];
accum = (accum<< 8)^ crc_table[((accum>> 24)^ (data[i]>> 16))& 0xFF];
accum = (accum<< 8)^ crc_table[((accum>> 24)^ (data[i]>> 8 ))& 0xFF];
accum = (accum<< 8)^ crc_table[((accum>> 24)^ (data[i]>> 0 ))& 0xFF];
}
return accum;
}
[sta,msg] = amg_iaptool_binconvert('source file','size','output file')
Example, run command at Matlab Command Window:
[sta,msg] = amg_iaptool_binconvert('stm32f4_user_app_stm32f4\stm32f4_user_app.bin','256k','stm32f4_user_app_convert.bin')
this demonstration imModel file, this demonstration implementing the Bootloader firmware. This model file will be program into sector A (Boot sector).
Demo model file: stm32f4_boot_256k.mdl
When “Boot” block located in the model and after build model, Waijung will generate call to function SYSTEM_BOOTLOADER() at file main.c.
This firmware will be program once from Auto Compile and Download or manual program via ST-Link tool.
File: stm32f4_user_app.mdl, this demo model disable auto compile and download.
The protocol of communication can be customized, in this demo use CAN Bus (CCP slave) for download ROM to upgrade.
This model need only compile, auto download will be disabled. The track build process show as below picture:
Configure the CAN bus interface and memory used by CCP slave handler.
Basic implementation for CCP slave. Only some command support in this demo.
Handle the memory transfer address.
This subsystem enabled only after receive CCP connect command. List of command support implemented in this demo:
The binary conversion tool will generate output file stm32f4_user_app_convert.bin with embedded CRC32 at the end of memory sector (256kB size).
When the target run in User Application (programming done at previous step), then it is now able be handle the IAP protocol.
To program the Target board via IAP (CAN), Host PC need another STM32F4 or STM32F0 board with CAN interface to convert the UART command to CAN message, and also receive CAN message then convert to UART response back to Host PC. As shown below diagram.
Build model file stm32f4_can_serial_bridge_binary.mdl to run as CAN-Serial Bridge device. The protocol is similar to below URL except the target board is STM32F4: http://waijung.aimagin.com/index.htm?can_to_serial_bridge.htm
If use “aMG_USBConverter-N” or “aMG_USBConnect” for serial conversion, time for IAP may be reduced by set Latency to 1ms. Follow this instruction: http://waijung.aimagin.com/index.htm?latency_time_setting.htm
At Matlab command windows, run command as show in below picture.
Wait until IAP process to finish.
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Stream mode | to Aimagin Connect--to Matlab--to Target | Select whether the camera feed should be streamed to Aimagin Connect, to Matlab Simulink or to Target ESP32. |
| Camera Module | AIMAGIN Camera--Custom Camera | Select the camera module. |
| Camera Pins | Enter the camera pin connections. | |
| XCLK frequency (Hz) | Enter the clock frequency | |
| LEDC TIMER | Enter the LEDC TIMER | |
| LEDC CHANNEL | Enter the LEDC CHANNEL | |
| Image Format | RGB565--YUV422--GRAYSCALE--JPEG--RGB888--RAW--RGB444--RGB555 | Select the image format. |
| Frame Size | QQVGA--QCIF--HQVGA--QVGA--CIF--VGA--SVGA--XGA--SXGA--UXGA--QXGA | Select the frame size of the camera feed. |
| JPEG quality | 0 to 63 | Enter the required quality of the image. |
| Number of frame buffers to be allocated | Enter the number of buffer frames to be allocated. | |
| Sample time (sec) | -1 (inherited) or specify | Specify the sample time |
This block is based on the esp32-camera driver by Espressif.
Previous : vTaskDelay Block
Next : Mesh Setup
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| URL | Enter the URL of the video stream. In the Camera Block mask description it is shown how the URL is generated. | |
| Frame Width | Enter the width of the expected frame of the video feed. | |
| Frame Height | Enter the height of the expected frame of the video feed. | |
| Sample time (sec) | -1 (inherited) or specify | Specify the sample time |
This block is used to receive the video, streamed from the Camera Block via Matlab Simulink. Th is can also be used to receive the video feed from any IP camera to Matlab Simulink as well.
This block only works for simulation and does not support code generation. For this block to function Host Setup Block block is required.
Stream video to Matlab Simulink
Previous : String Processing Block
Next : Host Setup Block
Stream video to Matlab Simulink
Stream video to Aimagin Connect
Stream video to Target
Mode: Setup
Mode: Write
Mode: Read
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Mode | Setup--Write--Read | Select the operation mode |
| Buffer Name | Allocate the name of the circular buffer | |
| Length of the buffer | Number of dataset rows to be held | |
| Input Format | Data types of each data in a dataset row | |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time |
This block can be used to temporarily hold data to ensure no data loss when saving the data (for example: to a database) due to a blocking process.
The number of datatypes the user specify in the Input Format parameter is the number of circular buffers which the block would create. All of these circular buffers will have a common head and tail index trackers. Length of the buffer parameter specify the number of indexes for each circular buffer. The circular buffer block will only work when activation signal input port is connected to Boolean 'true' signal.
Previous : Host Setup Block
Next : Digital Output demo
Create a database in the SD card using an Database browser. The following query can be used.
CREATE TABLE "smc_4_20mA_data" (
"timestamp" INTEGER,
"CH1_raw" TEXT,
"CH1_conv" TEXT,
"CH2_raw" TEXT,
"CH2_conv" TEXT,
"CH3_raw" TEXT,
"CH3_conv" TEXT,
"CH4_raw" TEXT,
"CH4_conv" TEXT
);
Demo file : esp32_circular_buffer_demo.slx
This demo shows a simple use case scenario for the circular buffer block. In this example data of 8 sensors (not actual sensors. Matlab Simulink blocks were used to mimic sensors) along with the UNIX timestamp needs to be inserted to the database. Inserting large amounts of data to a database could be a blocking process. Thus to ensure sensor readings are recorded every 1 second a circular buffer is used to hold the sensor data as an intermediate before writing to the database using the SQLite block.
Change the following configuration parameters in the model file.
In the WIFI BlockWhen running the user could monitor INSERT commands to the database using a serial monitor. After a while the user could connect the SD card to a PC and check the sensor readings using a Database browser.
Previous : HTTP Server demo
Next : LEDC demo
This tutorial shows how to use Aimagin Connect to design web applications and export it to ESP32 Aimagin Connect server
Once the web application is saved in Aimagin Connect, go to Save as Web app to create it as a web application as in the following figure and give a name for the web application
Then go to Web app under System Settings as in the following figure.
Click on create to create a publish a new web application.
Then give a name to publish the web application and select the web app that you want to publish and click on update to save the data
Next go to Permission page under System Settings to give the permission to the new web application
Then select your role and go to edit
Check the new web application under Web app | Permission and give the full permission by click on All button and Click on update to save the configuration. Then refresh the web page and the new web app will appear under the Web App in the left menu.
Once all the web applications are designed and published on Aimagin Connect go to export page to get all the web applications and other data to your device (laptop or desktop computer).
Then click on Export button to save the export folder.
Next extract the downloaded zip file. The extracted file directory should be as follows
Copy those folders to the root directory of the SD card and insert in to the ESP32.
Note: to tun the web applications on ESP32 a simulink model with Aimagin connect server in WiFi Access point mode is required.
Use the following test model to test the web applications on Aimagin Connect on ESP32.
Previous : Integrate Legacy C code to Waijung 2 using s-function builder
Next : Modify Simulink generated C code
Download demo file stm32f4_digital_output_demo_stm32f4.7z
Objective: Combine waijung_hwdrvlib.c and stm32f4_digital_output_demo.c into libcustom_lib.a.
It is assumed that the source code were generated with Waijung Blockset. Hence, all the source code, make file, and autoexec (.bat) file are automatically generated and available.
Example Command
D:\waijung\trunk\waijung\utils\gnu_tools_arm_embedded\bin\arm-none-eabi-gcc -I . -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -ffast-math -Wall -Wextra -Ofast -std=c99 -c waijung_hwdrvlib.c stm32f4_digital_output_demo.c
Do not forget to change your working directory from DOS command prompt to where the source file resides.
Note
As a result waijung_hwdrvlib.o and stm32f4_digital_output_demo.o are created.
Example Command
D:\waijung\trunk\waijung\utils\gnu_tools_arm_embedded\bin\arm-none-eabi-ar -r libcustom_lib.a waijung_hwdrvlib.o stm32f4_digital_output_demo.o
combines waijung_hwdrvlib.o stm32f4_digital_output_demo.o in to libcustom_lib.a.
As a result libcustomcode.a is created.
Note
The library file must always begin with the word “lib”.
Modify the make file (*.mk) as shown below.
Note
Build the system by running the bat file.
Example Command
stm32f4_digital_output_demo.bat
The binary file is generated and can be loaded to the target as usual.
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Select DAC output pins | GPIO 25--GPIO 26 | Select the output pin/pins |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time for the block |
Use the Digital to Analog Convertor (DAC) Block to generate analog signals.
The DAC block takes inputs as raw data (between 0 - 255) and generated output analog signals according to the following equation.
Analog output voltage = VREF x INPUT / 255
Previous : ADC Block
Next : WIFI Block
Demo file : esp32_dac_demo.slx
This demo shows how to use the DAC module with DAC Block. The DAC pin (GPIO25) generates a Sinusoidal Waveform with 0 - 2.56v with a frequency of 10 rad/sec.
Connect the DAC pin (GPIO25) to an oscilloscope to observe the wave form.
The generated waveform should be as below
Previous : ADC demo
Next : WIFI demo
ชื่อ ตาราง
-เป็นตัวใหญ่ทั้งหมด
-ใช้ underscore ขั้นระหว่างคำ
ชื่อ field
-ชือเต็ม
-เป็นตัวใหญ่ทั้งหมด
-ใช้ underscore ขั้นระหว่างคำ
4 fields มาตรฐานที่ต้องมีในทุกตาราง
ชื่อ field : field description (คำอธิบาย)
ชื่อข้อมูล_ID: ไอดีของ... (ไม่ใช้คำว่ารหัสเพื่อป้องกันการซ้ำกับจำพวก CODE)
CREATED_DATE: วันที่สร้าง (ISO date ex. 2020-12-03 21:02:00)
MODIFIED_DATE: วันที่แก้ไข (ISO date ex. 2020-12-03 21:02:00)
CREATED_BY: สร้างโดย (กรณีระบบนำเข้าข้อมูลใส่ SYSTEM)
MODIFIED_BY: แก้ไขโดย (กรณีระบบนำเข้าข้อมูลใส่ SYSTEM)
Download demo file Motor_Encoder.7z
DC motor is a device that converts electrical energy into mechanical energy. DC motor structure consists of two main parts: a permanent magnet and a coil. There is also a brush which is connected to an external electric power to the coils of the motor. When coil is powered on, there is a magnetic field around the coil.
Figure 1-1: Example of DC motor
Figure 1‑1 shows the basic structure of DC motor. There are two lines of the motor i.e. black (negative polarity) and red (positive polarity). Rotation of the motor is based on the application of the voltage polarity applied to the lines of the motor. Motor can rotate in clock and anti-clock wise direction. The speed of the motor can be decreased by controlling the voltage of the power supply. The DC motor is cheap and easy to use. Use of DC motor is widely found in daily use items such as small toys, electric bikes, robotic arms and industrial projects etc.
DC motors typically operate at a voltage level which is not suitable for microcontroller to work. Therefore, DC motor cannot be directly connected to the microcontroller but with the help of current driver.
DC motor drive current is mostly an H-Bridge circuit which consists of a transistor which acts as a switch of 4 units (Q1 to Q4) via a dedicated DC motor. Figure 1‑2 (a) shows the position of the transistors in the H-bridge which are responsible for controlling the current in the motor. When sending the control signal to Q1 and Q4, Q2 and Q3 will be disabled and the current will flow from A to B which will enable the motor to rotate in one direction. This is shown in Figure 1‑2 (b)
When the control signal is sent to Q2 and Q3, Q1 and Q4 transistors will be disabled and current will flow from B to A and the motor will rotate in reverse directions. This is shown in Figure 1‑2 (c).
Figure 1-2: H-Bridge circuit for controlling the rotation of DC motor
H-bridge circuit can be easily found in integrated circuit form such as L293D or L298N which helps in the reduction of size and make it easy to use. PWM direction control signals can be of 1 bit or 2 bits as shown in Figure 1‑3.
Figure 1-3: Connecting microcontroller with DC motor via control circuit
Figure 1‑4 shows aMG MotorCtrl2 board which is used in this experiment with a variable speed DC-Motor having a PWM signal on board which can drive current up to 1 A and can control the speed and direction of DC motor.
Figure 1-4: aMG MotorCtrl2 board
Figure 1‑5 shows how to control the direction of a DC motor using a control signal with the help of 2 bits which have 4 modes. These four modes are forward, reverse, brake and standby.
Figure 1-5: Using IC LB1836M [1, p. 3]
As far as choice of motors is concerned in this experiment, aMG MotorCtrl2 recommends using the interactive servo motor from Lego Mindstrom NXT. Following are the technical features of the motor.
Figure 1-6: Interactive Servo Motor (Image provided by LEGO education)
Aim
Figure 1-7: Device for adjusting the speed of motor
Figure 1‑7 shows the devices used for controlling the speed of the motor. The procedure for conducting this experiment is as follows.
Figure 1‑8 shows the Simulink model for the experiment for controlling the speed of the motor. It consists of PMW with fine duty cycle (with the help of variable resistor). SW1 and SW2 switches are used to control the direction of rotation of the motor.
Figure 1-8: Simulink model for testing the speed of the motor
Download the Simulink model on STM32F4DISCOVERY board and connect the power supply with external power source. When SW1 switch is press and hold, the motor will start rotating in one direction as shown in Figure 1‑9. When SW1 is released, the motor will gradually stop (Standby). When SW2 is press and hold, the motor will start rotating in opposite direction. When both switches (SW1 and SW2) are pressed, the motor will halt suddenly (Break).
Figure 1-9: Indicates the direction of rotation with respect to the switches
Question: If user wants to use Potentiometer to adjust both speed and direction of DC motor without push button switch?
If the read value is more than 1.75V (which is the middle position of the potentiometer), start forward rotation and rotate it at maximum speed (the read value will be 3.3V at maximum speed). If the read value is less than 1.75V, start reverse rotation and rotate it at maximum speed (at maximum speed the read value will be 0V).
Figure 1-10: Simulink model for controlling the motor with a potentiometer
To analyze the condition, Simulink model is shown in Figure 1‑10 and the description is as follows.
Position control or motion with the help of motor have many applications in the field of automation and robotics. In order to improve the speed and accuracy of the work, feedback control system is very important. The data form the motor speed reading is fed back to the processor to adjust the appropriate control signals.
Rotary encoder is an electro-mechanical device that measures the angular position or speed of rotation of the axes. It consists of a circular plate which is mounted to the spindle. Light sensor and photo detector array reads the optical pattern that results from the disc’s position at any one time which is shown in Figure 2‑1. The resolution measurement depends on the number of slots per cycle such as encoders with 180 number of channels can measure an angle up to 360/180 = 2.0 degrees.
Figure 2-1: Structure of Rotary Encoder
When encoder’s axis starts rotation, channels on the disc will run through the light sensor. The photo detector on the receiving end will sense the light signal and when the sensor is connected with the signal circuit, the system can recognize how many degrees the motor has rotated.
From Figure 2‑1, one can observe that the discs are translucent in 2 rows and are overlapped. To detect the direction of rotation, such as the motor is rotating in clockwise (CW) direction or counter clockwise (CCW) direction, can be done by measuring the phase difference between the Channel A and Channel B signals. If the signals from Channel A is leading from signals of Channel B then the motor is moving in clockwise direction and if the signals from Channel A is lagging behind Channel B, then the motor is moving in counter clockwise direction and this is shown in Figure 2‑2.
Figure 2-2: Characteristics of the signals from encoder with a phase difference of 90 degree
In order to detect the direction of rotation, pulse requires two sets of decoder circuits to indicate the rotational direction. The CW and CCW rotation have 0 and 1 values respectively. Based on the readings of the decoder, the count signal will be increased or decreased.
In addition, another advantage of using signals with the phase difference of 90 is that the user can adjust the resolution of the count which is shown in Figure 2‑3.
Figure 2-3: Signal encoder interfaces Quadrature
Channel A signal is chosen to be a reference signal. When the rising and falling edges of the channel A is equal to 3 then the count is (x1). When the rising edges and falling edges of the signal is equal to 6 (which is two times the number of pulses of the signal) then the count is (x2). When the rising and falling edges of the signal is 12 then the count is (x4) which is actually four times the number of pulses of Channel A signal.
If the encoder disc has 180 channels then how to count four times? Since the number of channels per cycle is equal to 180 x 4 = 720 slots thus the lowest possible resolution is 360/720 = 0.5 degrees and so on.
STM32 microcontroller family with a detection module and external signal read signals from encoder software which is the part of timer module. When connected to a signal from the encoder, both Channel A and Channel B to the microcontroller, the counter will count up or down to the rhythm of the received signal. This allows the user to reduce the process of programming. Just set the timer modules per line and then the counter that counts is immediately applied.
In this section, description will be given, how to read values from STM32F4DISCOVERY board with encoder module and timer. All 15 modules that can interface with the encoder has 6 sets of timer 1, 2-5 and 8
This lesson will show how to read values from the STM32F4DISCOVERY board, encoder module with Timer, but all 15 modules that can interface with encoder has 6 sets of Timer 1, 2 – 5 and 8 [2].
The encoder block is in Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> TIM and have the following characteristics and properties.
Figure 2-4: Characteristics of Encoder Read Block
The purpose of Encoder Read Block is the count the signals from the encoder both from Channel A and B. If both channels are selected then the maximum count will be equal to 4 x pulse per revolution (PPS). The output direction is the direction of rotation which is either 0 or 1. If ‘reset counter after every count read’ is selected then the counter will be reset to zero after reading the count.
Aim
Figure 2-5: Circuit for experimenting with the encoded signal from encoder software
Figure 2‑5 shows devices which are used in this experiment for reading the signals from encoder with same set-up steps as in previous section experiment on speed adjustment but add the signal link, encoder and aMG USB Converter N board for sending position read from encoder through USB.
Figure 2-6: Simulink model for reading the signals from encoder software
Figure 2‑6 shows a Simulink model for this experiment to read signal from the encoder. It contains Subsystem block for controlling the speed of motor with Potentiometer and push button switch as in Figure 1‑8. The value from Encoder Read Block is unsigned 16 bit integer. Figure 2‑7 shows an example of converting read value to signed integer.
Figure 2-7: Method for converting Encoder Read Block to be a signed integer
Download the model on STM32F4DISCOVERY and then connect the USB cable to the computer and switch on the motor. The reading of the encoder will be displayed in TeraTerm window as shown in Figure 2‑8.
Figure 2-8: TeraTerm window reading the encoded signal
Value is in the unit of count pulses. To change the display unit such as degrees, user need to learn from the manual about the number of channels of the decoder end plate and then gain ratio of the transmission is adjusted accordingly.
For example, rotation of 1 revolution (360 degrees) of the pulse multipled by 4×180 to get 720 pulses per cycle if user wants to get the value in degrees.
Gain = 360 / number of pulses per revolution = 0.2.
To show the value of the unit.
Gain = 1 / number of pulses per revolution = 0.0014.
Signal oscilloscope is used to inspect the signal from pin Enc A1 and Enc A2 of aMG MotorCtrl2 board and is shown in Figure 2‑9.
Figure 2-9: Signal from the encoder measured at the oscilloscope
Following example is based on retrieving the data from the selected table in the database. For this example, consider a database table with two columns (ID and name) and the web page which has two components; a drop-down menu and a text field. The drop down menu is used to select the ID. The content of ID drop down is automatically populated with ID data from the database. The Name text filed content automatically shows the corresponding name according to the selected ID, using change event callback. This example can be divided in to two sections.
First login to the Aimagin Connect system using [Link]
To create a table in the database, go to Transnational database under Database in Tool Box.
Then go to create as in the following figure.
Then name the table as 'example' an add two columns ID and Name to the table and update the table as follow (NOTE: if the example table is already in the system use another name or use that created table because the table name cannot be duplicated in the system ).
Likewise add the Name column as ID column
Then update the table to create it.
Next the data should be added to the table. For that go to Data tab, find the table and click on insert to add data.
There are two records in this table. For the first row ID: 1 and Name: Mr.A and for the second row ID: 2 and Name: Mr.B as in the figure. Insert the data as follows.
Once the data is inserted to the each row, update it.
The final table should be as follows.
Now creating table section is completed. Next task is to design the web page.
To design the web page, go to Aimagin Connect under Tool Box.
Then add a new page to the project and give a name to the page as in the following figure.
Then add the required components from the components pane. For this example, there are two main components; drop down menu and a text field. In addition to that put those two components under a container and add the text component under a row component and a column component as in the following figure. Change the label of the drop down menu in Parameter section to ID and the label of the text field to Name. And change the ID of the drop down menu and the text field as in the figure.
To automatically add the required ID numbers to the drop down menu, a callback function should be required. Initialize following function to the init callback to add the ID numbers from the database.
The ID data from the database should be saved as an array to add them to the drop down menu using 'setParameter'. The ID data can be acquired from the database using 'AmgCnt.SQLite.read.all'. The source code is as follows. The function 'AmgCnt.SQLite.read.all' is consisted with main parameter 'sql' to call the required sql.
var id_array = [];
var dropid = this.id;
AmgCnt.SQLite.read.all({
sql: "select ID from example ",
params: []
}, (res) => {
if (res.rows != undefined) {
for (var i = 0; i < res.rows.length; i++) {
id_array[i] = res.rows[i].ID;
}
setParameter(dropid, 'Options', id_array);
}
console.log(res);
}); Note: if the table name is not as above change table in sql
sql: "select ID from 'table_name' ",
Next add a function to change callback of the drop down menu to get the name of the person which corresponds to the selected ID number and show it in the text field when the selection of the drop down menu is changed. The callback function is as follows. The selected data in the drop down menu can be get using 'getParameter' and show the corresponding data in text field using 'setParameter'.
The source code for change callback function is as follows.
AmgCnt.SQLite.read.get({
sql: "select * from example where ID = ?",
params: [getParameter('dropId', 'Value')]
}, (res) => {
if (res.row != undefined) {
setParameter('txtName', 'Content', res.row.Name);
}
console.log(res);
});
In the callback function, first get the corresponding name from the database using 'AmgCnt.SQLite.read.get' function. Add the required SQL to the function. For this example write the sql to get data which is related to the selected ID value. After that, the acquired data should be displayed in the text field. For that, if the data is available display the name of the person using the 'setParameter' function.
The function 'AmgCnt.SQLite.read.get' is used to get the data from a single row and the function 'AmgCnt.SQLite.read.all' is used for getting data from all rows. Once the web designing is finished save the project using save button
If the web page is previewed and select an ID from the drop down menu it should be as in the following figure.
This example shows how to design a web page to setup the WiFi configuration in station mode for ESP32 and another web page for showing some data using widgets.
Web page designing in Aimagin Connect is very user friendly and easy to use with dragging and dropping components and can be designed advanced web pages using it with a minimum knowledge on web designing. Developing most of the web pages for SMC on Aimagin Connect can be divided in to two sections.
Following documentation demonstrates developing each web page on Aimagin Connect step by step.
Database table is used to save the WiFi configuration data to connect the ESP32 to the internet via wifi router to upload the data to a server. There are seven user input parameters(SSID, Password, Static or Dynamic selection, IP address, Subnet mask, Gateway and DNS) on this page. For each parameter, there should be a separate column in database table. Creating a new database table in Aimagin Connect is as follows.
Once login in to the Aimagin Connect server on the web go to Transnational database under Database in Tool Box as in the following figure.
Then go to create as in the following figure to create a new table.
Change the name of the table to wifi_config and click Add to add required columns to the table (Note: if the table cannot be named as wifi_config use another name.)
In column setting, add the required Column name and the suitable data type. In this scenario set the column name as SSID and the data type as TEXT. And then click OK to add that column to the table as in the following figure.
Likewise add the required remaining columns for the wifi_config table as follows and click Update to finalize the table.
For designing a web page go to Aimagin connect under Tool Box as in the following figure
Then click New and select New page on top menu to add a new page to the current project
Change the title of the page under property as in the figure. The title of the page will be displayed on the web browser tab.
The required components and widgets are in the Components section
First add a topic to the page. For that drag and drop a container on to the page. The container is under Grid in Components. Then drag and drop a Row on to the Container. If the Row component is dropped on the Container it will make a row inside the Container. Then drag and drop a Col component on the Row component to create a column inside the row. And after that drag and drop a Div component on the Col (column) component. Set the text align as center in Property panel of the Div component to align the text center. Then drop a Label component on the Div component. Click on the added label component and change the Content on Property panel to WiFi Configuration and change the other parameters as required as follows. The component tree will be as in the following figure.
Then add the required text fields, radio buttons and buttons to the WiFi config page. There are six text fields , two radio buttons and two buttons in this page. The six text fields are used to display and let the user to input SSID, Password, IP Address, Subnet Mask, Gateway and DNS. The two radio buttons are used to select the WiFi configuration in Static or Dynamic and the two buttons are used to submit and clear the form data. Before add those components, add a Container component and then add the other components as below. Change the labels and the IDs of the text fields and the radio buttons as in the figure below. The label for text fields can be changed in the Label parameter under the Parameter in text field property pane.
To add the options to the radio button, click on the radio button and go to edit in options under property panel.
Then add two custom options by clicking on Add custom options and name it as Dynamic and Static and save as follows.
Once the web designing is completed the connection between the database table and the web page components should be established. The main feature in this WiFi configuration page, Target Server page and the Analog input configuration page is once the page is loaded it will automatically show the saved data from the database table. For that a callback function should be implemented as follow.
First click on the page and click on the edit on init under event callback.
Add the callback function as below. Once the function is implemented click Save.
AmgCnt.SQLite.read.get({
sql: "select * from wifi_config where ROWID = ?",
params: ['1']
}, (res) => {
setParameter('txtSSID', 'Content', res.row.SSID);
setParameter('txtPassword', 'Content', res.row.Password);
setParameter('rdiAccessPoint', 'Value', res.row.Access_P);
setParameter('txtIP', 'Content', res.row.IP);
setParameter('txtSubnet', 'Content', res.row.Subnet_m);
setParameter('txtGateway', 'Content', res.row.Gateway);
setParameter('txtDNS', 'Content', res.row.DNS);
console.log(res);
});
In this callback function, the web page acquires data of the first row from the wifi_config table using AmgCnt.SQLite.read.get function with the suitable SQL and each column data from the table will be shown in the each web page component with the setParameter function. In this setParameter function the first parameter should be the Name of the component, the second parameter will be the parameter that you are going to change; for the text fields the parameter is the Content. The third parameter is the value; in this case the particular column data from the database table.
In the WiFi configuration the user select Dynamic in radio buttons the IP Adderss, Subnet mask, Gateway and DNS text fields should be disabled. It should enable when the user select Static in wifi configuration. For that a callback function should be implemented when the selection of the radio button is changing. Click on the radios component and click on the edit in the change event under event callback.
The callback funtion should be as follow. It basically disable those text fields if the selection is Dynamic. Otherwise it will enable the text fields.
var v = getParameter('rdiAccessPoint', 'Value');
!setParameter('txtIP', 'Enable', v=="Static");
!setParameter('txtSubnet', 'Enable', v=="Static");
!setParameter('txtGateway', 'Enable', v=="Static");
!setParameter('txtDNS', 'Enable', v=="Static");
Next the callback function for the Update button. For this the data in each text fields and the radio buttons should be inserted to the wifi_config table. Click on the Update button component and go to Edit of the mouseclick event under Event callback as follow.
Add the following functions to the mouseclick event
AmgCnt.SQLite.read.get({
sql: "select SSID from wifi_config ",
params: []
}, (res) => {
if (res.row == undefined) {
AmgCnt.SQLite.create.run({
sql: "insert into wifi_config (SSID, Password, Access_P, IP, Subnet_m, Gateway, DNS) values(?, ?, ?, ?, ?, ?, ?)",
params: [getParameter('txtSSID', 'Content'),getParameter('txtPassword', 'Content'),getParameter('rdiAccessPoint', 'Value'),getParameter('txtIP', 'Content'),getParameter('txtSubnet', 'Content'),getParameter('txtGateway', 'Content'),getParameter('txtDNS', 'Content')]
}, (res) => {
alert("Data has been inserted");
});
} else {
AmgCnt.SQLite.update.run({
sql: "update wifi_config set SSID = ? ,Password = ?, Access_P = ?,IP = ?, Subnet_m = ? ,Gateway = ?, DNS = ? where ROWID = ?",
params: [getParameter('txtSSID', 'Content'),getParameter('txtPassword', 'Content'),getParameter('rdiAccessPoint', 'Value'),getParameter('txtIP', 'Content'),getParameter('txtSubnet', 'Content'),getParameter('txtGateway', 'Content'),getParameter('txtDNS', 'Content'),'1']
}, (res) => {
alert("Data has been updated");
});
}
console.log(res);
});
In this event, the data in all components is gathered and saved in the wifi_config table. First the client checks whether the data is already in the first row in the wifi_config table. If it is not, the data will be inserted to the first row. If the data is already in the first row, it will update the first row with the current data. AmgCnt.SQLite.create.run function is used to insert the data to the table and AmgCnt.SQLite.update.run function is used to update the data with the current data. getParameter function is used to get the user entered data form the web component (from the text field or from radio button).
The last callback function is used to clear the data of the web page using the clear button. For that click on the clear button and go to mouseclick event of that button and add the following function to clear the data on each component (in text fields and radio buttons).
setParameter('txtSSID', 'Content', '');
setParameter('txtPassword', 'Content', '');
setParameter('rdiAccessPoint', 'Value', '');
setParameter('txtIP', 'Content', '');
setParameter('txtSubnet', 'Content', '');
setParameter('txtGateway', 'Content', '');
setParameter('txtDNS', 'Content', '');
Once the web page designing is finished save the project using the save button and preview the designed web page using preview button as in the following figure.
The final web page looks as follow. Try with adding data to the web page and submit those data. Once you load the page again it will show the last submitted data that you entered.
Previous : Develop simple web application that retrieves values from database
Next : Modify Simulink generated C code
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Settings interface | Basic--Advanced | Allow user to adjust the level of control over the specified pins. |
| Select input pins | Pino 0 to Pin 39 | Select the output pins to be configured. |
| Pin mode | None (floating)--Pull-up--Pull-down--Pull-up and Pull-down | Only pins that support both input & output have integrated pull-up and pull-down resistors. Input-only GPIOs 34-39 do not. |
| Pin hold | Enable--Disable | The GPIO pad hold function works in both input and output modes but must be output capable GPIOs. If pad hold enabled: in output mode: the output level of the pad will be force locked and cannot be changed. in input mode: the input value read will not change, regardless the changes of input signal. The state of digital GPIO cannot be held during Deep-sleep, and it will resume the hold function when the chip wakes up from Deep-sleep. If the digital GPIO also needs to be held during Deep sleep, gpio_deep_sleep_hold_en should also be called. |
| Deep sleep pin hold | Enable--Disable | Enable/Disable deep sleep pin. |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time of the block |
This block implements Digital Input Module to generate digital input logic from MCU pin.
Each block is used to configure pins of a specified block.
You can have as many Digital Input Blocks as you need in a model, to configure different pins of the MCU.
Previous : Digital Output Block
Next : GPIO Interrupt Block
Demo file : esp32_digital_input_demo.slx
This example shows how to use the Digital Input Block on ESP32. The state of the digital input pin (GPIO 4) will be represented on the digital output pin (GPIO 2).
Once the digital input pin is connected to a button and the digital output pin is connected to a LED when running the demo on ESP32 , the LED turns on when the button is pressed and the LED turns off when the button is released.
Previous : Digital Output demo
Next : GPIO Interrupt demo
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Settings interface | Basic--Advanced | Allow user to adjust the level of control over the specified pins. |
| Select output pins | Pino 0 to Pin 34 | Select the output pins to be configured. |
| Initialize the above pins | Check--Uncheck | |
| Pin mode | Push pull--Open drain | |
| Drive capability | Weak--Decent--Normal--Strongest | Select drive strength of the pins. |
| Pin hold | Enable--Disable | Even though the GPIO pad hold function works in both input and output modes, it must be output capable GPIOs. If pad hold enabled: in output mode: the output level of the pad will be force locked and cannot be changed. in input mode: the input value read will not change, regardless the changes of input signal. The state of digital GPIO cannot be held during Deep-sleep, and it will resume the hold function when the chip wakes up from Deep-sleep. If the digital GPIO also needs to be held during Deep sleep, gpio_deep_sleep_hold_en should also be called. |
| Deep sleep pin hold | Enable--Disable |
This block implements Digital Output Module to generate digital output logic from MCU pin.
Each block is used to configure pins of a specified block.
You can have as many Digital Output Blocks as you need in a model, to configure different pins of the MCU.
Previous : Target Setup Block
Next : Digital Input Block
Demo file : esp32_digital_output_demo.slx
This example shows how to use the Digital Output Block on ESP32. The Counter Limited block is used to control the four digital output pins. The upper limit of the counter is 4.
Once the four digital output pins (GPIO2, GPIO4, GPIO5 and GPIO18) are connected to the LEDs and when the demo file is running on ESP32, the LEDs should turn on and off with the following sequence with 1s per state
Previous : Host Setup Block
Next : Digital Input demo
มี API สำหรับการอ่านไฟล์ให้
1. amgApi.coreLib.file.readCSV(fileObject, json)
สำหรับใช้อ่านไฟล์ CSV
มี parameter 2 ตัวคือ
1. fileObject เป็น Object ของ File ที่อ่านขึ้นมา
2. json เป็นตัวบอกว่าต้องการผลลัพธ์เป็น Array 2D หรือ Array ของ json
ตัวอย่างการใช้งาน
var files = getParameter('file-widget', 'Value');//ตัวอย่าง อ่าน value ของ file upload component จะได้ object ของ files หลาย files
amgApi.coreLib.file.readCSV(files[0], true).then(function(result) {
/*
result เป็น array 2D หรือ array ของ json ขึ้นอยู่กับการ set true/false ใน parameter ตัวที่ 2
json = true จะได้เป็น [{'col1':'value1', 'col2':'value2'}, ...]
json = false จะได้เป็น [['col1', 'col2'], ['value1', 'value2']]]
*/
});
2.amgApi.coreLib.file.readXLSX(fileObject, json)
สำหรับใช้อ่านไฟล์ XLSX (Excel)
มี parameter 2 ตัวคือ
1. fileObject เป็น Object ของ File ที่อ่านขึ้นมา
2. json เป็นตัวบอกว่าต้องการผลลัพธ์เป็น Array 2D หรือ Array ของ json
ตัวอย่างการใช้งาน
var files = getParameter('file-widget', 'Value');//ตัวอย่าง อ่าน value ของ file upload component จะได้ object ของ files หลาย files
amgApi.coreLib.file.readXLSX(files[0], true).then(function(result) {
/*
result เป็น array 2D หรือ array ของ json ขึ้นอยู่กับการ set true/false ใน parameter ตัวที่ 2
json = true จะได้เป็น [{'col1':'value1', 'col2':'value2'}, ...]
json = false จะได้เป็น [['col1', 'col2'], ['value1', 'value2']]]
*/
});
Note: after finish checking the ST-Link connection, ST-Link Utilities must be closed, to prevent connection error while Waijung run the Auto Compile and Download process during model build
The demo files for STM32F4 is located in the demo directory: waijungroot\targets\stm32f4_target\stm32f4\demo\
To run the existing demo for LED blinky, follow below steps:
Note: Waijung root and model file path mode not containing space or unicode (non-English) character.
download all demo files: RF_ADC_IO.7z
This demo will show you how you can use FiO Glide[name RF2] to read ADC value from LDR (aMG Photocell-A) then control an IO that drive an LED. Then send the read values (ANT protocol) to the second FiO Glide[name RF1], while RF1 also read its ADC value from LDR (another aMG Photocell-A) to control another LED. This second FiO Glide[name RF1] then gather all four values (ADC1,LED1,ADC2,LED2) and send via ANT protocol to the third FiO Glide[name RF0]. RF0 then read all values and send to PC via serial communication, then we use Simulink tools to display and plot values on scope.
The Vin for aMG Photocell-A module is connect to +3.3V (Pin38) and GND to Pin25. Vsense is then connected to ADC port Pin22 (AIN7), user can connect ADC to other pin if needed. The output pin is Pin20 (AIN5 configured as IO output), this drive LED at the anode, the cathode then connect to GND. Since FiO Glide can drive current up to 5 mA, it is safe to drive an LED with out a current limiting resistor.
When user connect USB power to the three boards, LEDs will light up on RF1 and RF2 at office lighting condition. If user put a flash light on LDR with light intensity high enough, then LED will go OFF, and ON again if you remove flash light. This behaviors go the same on RF1 and RF2 modules. The values are sent to host PC and plot on Simulink scope. ADC values show in Volt and LED status show 1 and 0, representing ON and OFF status.
Please follow video tutorial found in (https://drive.google.com/file/d/1ri3UblJqNCHNO0CJDECyfvXyqoCwTAe9/view?usp=sharing) or (svn\quasense\esp32 flash tools and video\)
1.Turn ON and connect ESP32 to the PC via USB
2.Download ESP32 flash download tools (https://www.espressif.com/en/support/download/other-tools)
3.Open the application and select ESP32 download tool
4.Download ESP32 bin files (provided by Aimagin separately)
5.Select the files and their offset values as shown in the video
6.Check the COM port typically use the lower value COM port
7.Apply correct COM port and buad rate and other settings as shown in video
8.Click start, this will show connection to board in the DETECTED INFO section (it is done just to verify connection to the board), if this step doesn't work please change COM port to the other one and try this step again
9.Now Select all the tick boxes for bin files and click START again
10.Wait for FINISH message, and then reset ESP32 (press reset button or turn off ESP32 and turn on ESP32)
This tutorial aims at teaching beginners how to use RapidSTM32 Blockset in ONE DAY (approximately 6 hours). After completing the tutorials, you will have enough basic knowledge to use the Blockset to implement a variety of basic but useful applications such as:
Yes!! all those within 6 hours, no kidding. We are truly taking about Rapid Prototyping. That's Why our duck can peel banana skin? :)
RapidSTM32 LogoRapidSTM32 is a Simulink device driver blockset and tool suite for STM32 microcontroller family.
Ultimately, the blockset is expected to enable users to transfer their designs from Simulink, with just one click, to a working embedded system (based on STM32 microcontrollers) without the need to write a single line of C or Assembly code.
The blockset works by taking advantage of the Mathworks Inc.'s products, i.e. Real-Time Workshop and Real-Time Workshop Embedded Coder, code generation capability.
The blockset is not intended to be a comprehensive embedded target, allowing users to adjust every single bit in every single register.
Rather, its focus is on helping users (especially beginners in embedded systems) implement such complex systems or algorithms as event-driven real-time applications or Kalman filtering as Fast-Easy-Fun as possible without the need to understand RTOS or perform low-level device configuration or debugging.
Rapid STM32 bridges the gap between the high-performance graphical programing language, real-world applications, and the users with low-cost moderate-performance hardware.
Ideally, RapidSTM32 is for anyone who needs to make use of an embedded system, a kind of a miniature computer on a single piece of Printed Circuit Board (PCB), but don't know how to or do not want to write a low-level program for it.
Basically, if you already know Matlab and want to do one of the following tasks:
Then RapidSTM32 is definitely for you.
RapidSTM32 can convert your Matlab program to a working system in just a few mouse clicks. All you need is standard Matlab tool suite, RapidSTM32 Blockset and FiO evaluation board. You do not need to write a single line of code.
Additionally, for students and lecturers in automatic control or DSP courses, RapidSTM32 Blockset will definitely help students:
Additionally, for students and lecturers in automatic control or DSP courses, RapidSTM32 Blockset will definitely help students:
Pictures are worth a thousand words.
The conventional Way of developing embedded systems.
The RapidSTM32 Way.
In Thailand, there is a saying "as easy as peeling a banana skin".
Our goal for RapidSTM32 is to make using microcontrollers as easy as peeling banana skin.
Thank you Viree for the Design.
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STM32 is a family of 32-bits ARM Cortex-M3 microcontrollers developed and marketed by STMicroelectronics.
ARM Cortec-M3 is based on ARMv7-M architecture which is not the same as ARM7. ARM7 microcontrollers are based on ARMv4 architecture.
Basically, ARM Cortex-M3 has been designed to improve upon and overcome several limitations of ARM7.
Read a Cortex - M3 white paper (An Introduction to the ARM Cortex-M3 Processor) from ARM Inc
This article reports a simple speed test between STM32 and other MCU.
RapidSTM32 Blockset is offered with two sets of features:
Full-feature set is available only when FiO family of Evaluation Board (EVB) is physically connected to the host PC. FiO is a family of EVB that has been specifically designed to work seamlessly with RapidSTM32 Blockset and is offered at an affordable cost. In this respect, in addition to being an evaluation board, FiO is also a hardware key that enables the full features of RapidSTM32 Blockset.
Nevertheless, the generated source code is available for both full and limited features. "Therefore, in theory, even with limited-feature set you can modify the source code in anyway you like to suit your needs."
The following table lists and compares the features of RapidSTM32 Blockset.
| Limited-feature | Full-feature | |
| Clock speed max. | 24 MHz | Unlimited |
| Digital IO | Unlimited | Unlimited |
| ADC | 2 channels max. | Unlimited |
| DAC | 1 channel max. | Unlimited |
| PWM | 2 channels max. | Unlimited |
| RTC | Unlimited | Unlimited |
| USART | 2 element max. | Unlimited |
| USB Virtual COM | No | Yes |
| USB HID | No | Yes |
| Character LCD | Yes | Yes |
| SD card | No | Yes |
| GPS NMEA Parser | No | Yes |
| GPS Simulation Blockset | Yes | Yes |
| Auto Compile | No | Yes |
| Auto Download | No | Yes |
| USB In Application Programming | No | Yes |
| USART In Application Programming | No | Yes |
Our choice to adopt STM32 is based on trade offs between price, performance, and ease-of-use.
We classify microcontrollers roughly in 3 groups.
In terms of performance TI C2000 is very powerful with 300MIPS (Delfino) and hardware floating point unit. However, it is neither cheap to get started (eZdsp kits start from $500+) nor easy to use in custom board with high pin counts (176+) LQFP or BGA package.
8-bits or 16-bits microcontrollers are cheap (starter kits may start from about $40) and they are easy to use in custom board. However, the performance is limited, e.g. 16-bits and 40MIPS max. for dsPIC33.
In our opinion, ARM Cortex-M3 offers the best compromise. It is comparable to 16-bits microcontrollers in terms of price (ARM Cortex-M3 development kits start from about $20) and ease-of-use in custom board. Additionally, with 32-bits and 90MIPS, it offers superior performance to 8/16-bits systems.
We did a simple test. We declare two variable a = 1.1 and b = 2.2. We time how fast the program execute this single line c = a*b; using built-in stop watches in MPLAB IDE and Keil RealView MDK. The results are as follows.
Time taken in micro sec (10^-6) to execute a single line of code "c = a*b"; where a = 1.1; and b = 2.2;
| IDE | MPLAB | Keil RVMDK | |
| Settings | Optimization Level 3 | Optimization Level 3 use MicroLIB | Optimization Level 3 do not use MicroLIB |
| CPU (Running Speed) | dsPIC33 (40MIPS) | STM32F103RE (90MIPS) | STM32F103RE (90MIPS) |
| a,b,c data type IEEE float (32 bits) | 3 | 2.58 | 2.13 |
| a,b,c data type IEEE double (64 bits) | 8.125 | 5.88 | 2.54 |
Remark
RapidSTM32 Blockset itself is free and is released under BSD license.
At present, however, RapidSTM32 is NOT opensource.
RapidSTM32 Blockset is offered with two sets of features:
Full-feature set is available only when FiO family of Evaluation Board (EVB) is physically connected to the host PC. FiO is a family of EVB that has been specifically designed to work seamlessly with RapidSTM32 Blockset and is offered at an affordable cost. In this respect, FiO EVB may be viewed as a hardware key that enables the full features of RapidSTM32 Blockset.
Nevertheless, the generated source code is available for both full and limited features. "Therefore, in theory, even with limited-feature set you can modify the source code in anyway you like to suit your needs."
For a comprehensive list of feature comparison please see RapidSTM32 Features.
Yes. But with some limitations.
See this demonstration on How to.
Basically, just select "Generic" target board and then select your MCU.
Configuring RapidSTM32 for uses with Non FiO
When we started works on the Blockset and the evaluation board, we noticed that it can perform the following FOUR functions:
So, we called it Four in One (FiO).
What are the minimum requirements for Waijung2 installation?
error: java.lang.IllegalArgumentException: Negative time
Waijung2 building process is getting slower with Matlab 2020
error: Failed to connect to ESP32: Timed out waiting for packet header
In the previous chapter, we have discussed about MATLAB and Simulink, how we can use them and what are the advantages using these tools. In this chapter our prime objectives will be
We will start this chapter with minimum requirements.
We can categorize the minimum requirements into two sections based on the software requirements and hardware requirements.
Software requirements can be further classified into three categories and they are:
Above mentioned operating system can either 32 bits or 64 bits.
Mathworks Inc. software suite consisting of the following toolboxes and blocksets.
Table 1: Required tools for MATLAB/Simulink
Please note that Waijung Blockset supports both 32-bits and 64-bits operating systems, as well as, MATLAB 32-bits and 64-bits versions.
https://launchpad.net/gcc-arm-embedded
https://www.keil.com/demo/eval/arm.htm
http://supp.iar.com/Download/SW/?item=EWARM-KS32
ST Link Utility enables automatic flash programming directly after the build process as well as in-circuit debugging. Details regarding installation of ST Link Utility will be discussed in Hardware Requirements section.
Waijung Blockset and STM32F4 Target support a complete range of STM32F4 family of Hi-Performance & Digital Signal Processing (DSP) Microcontroller Unit (MCU). However, the cheapest and fastest way to get started is to test out the blockset with the STM32F4 DISCOVERY Kit which is a low-cost development Kit from STMicroelectronics. For as low as US$ 15, STM32F4DISCOVERY Kit can be purchased directly from Aimagin website from the following link.
https://www.aimagin.com/stm32-f4-discovery.html
Figure 1: STM32F4 Discovery
Following are the features of STM32F4 Discovery
The aMG USB Converter – N consists of two chips which are stacked together. On the left hand side of Figure 2, reader can see the two chips stacked together and in the middle and right hand side, reader can see both chips separately. The drivers for aMG USB Converter comes along with the package of Waijung but it is recommended to install the most up to date Virtual COM driver from FDTI website from the following link depending upon which operating system the user is using.
http://www.ftdichip.com/Drivers/VCP.htm
Figure 2: aMG USB Converter – N
Now the question comes, why we need to do this. The answer is very simple. It is very essential for Hardware Inter Loop (HIL) test and help the MATLAB/Simulink to communicate with the embedded target in real time for open loop and close loop up to 2 KHz and 1 KHz respectively. However actual performance depends on computer and software running on the system.
Once the drivers are installed, the user need to check whether the drivers are installed properly. This can be done by going to Device Manager of the operating system and looking at the Ports (COM & LPT). This hardware has two serial to USB port. By default aMG USB Converter N will be connected to channel 1 (normally the smaller port number).
Figure 3: Device manager showing two COM ports
Figure 4: Checking if the device is working properly
In order to make the embedded target work HIL in real-time environment, we need to change the port setting by going to USB Serial Port properties ->Port Settings -> Advanced. In the advanced settings of USB Serial Port properties, change the Latency Timer to 1.
Figure 5: Advanced settings for USB
Figure 6: Hardware connection
Now the next step is to install ST Link Utility on the operating system. There is a slight difference while installation of ST Link Utility installation on Windows 7 and Windows 8 in terms of drivers as shown in Figure 7 but rest of the procedure is the same.
Before the user proceed further, he/she must make sure that installation of MATLAB/Simulink as mentioned in software requirements is complete. The first step is the download and install ST Link Utility which allows the communication between the target (STM32F4 board) and Simulink or PC. Furthermore ST Link Utility is also useful for programming the flash memory. ST Link Utility V2 can be downloaded from STMicroelectronics website. The direct link to download is as follows.
http://www.st.com/web/en/catalog/tools/FM146/CL1984/SC724/SS1677/PF251168
When the user will click on the page, then user need to scroll down where description as shown in Figure 7 will be given.
Figure 7: ST Link Utility Download options
Respective drivers can be downloaded based on the operating system installed on the computer and proceed with the installation. When the installation is done, connect the target. The target can be:
For STM32F4 Discovery, connect the target with the computer via USB as shown in Figure 8. STM32F4 Discovery has ST Link V2 debugger on the board.
Figure 8: Computer and STM32F4 Discovery connection
However FiO2 requires a separate debugger ST Link V2 which can be purchased from Aimagin website from the following link.
https://www.aimagin.com/st-link-v2.html
Go to the installed ST Link Utility and click on Connect to Target.
Figure 9: STM 32 ST Link Utility
If the target is not connected properly or/and hardware is malfunctioning, then error will be displayed which is shown in Figure 10.
Figure 10: Displaying error while connecting STM 32 ST Link Utility with the target
If everything is fine, then user can see window as shown in Figure 11.
Figure 11: Successful connection between STM 32 ST Link Utility and the target
Next is to go to ST-LINK->Update Firmware update. A new window will open as shown in Figure 12.
Figure 12: Updating Firmware
Then click on Device Connect as highlighted in red in Figure 12. If the firmware is not up to date it will give an option to update. Click on Yes to do so. Please note that if the user get error while updating the firmware then just unplug the target from the computer and connect it again. Re-try then.
Run MATLAB as administrator.
Go to the location on the local hard drive where waijung14_03a is available. Inside that folder there will be file named install_waijung.m. Open the file using MATLAB and click on Run.
Now the installation process will begin and it will take some time. If everything is OK then the user can see something similar like Figure 13. At the end of installation, MATLAB will pop-up Enable Automatic Update checking window will appear. It is strongly recommended to click Yes on that.
Figure 13: Waijung Installation
At the end, the use need to check if Waijung can communicate with the target. For that purpose, user should type waijung.checkTargetConnection and it will give options to select the target as shown in Figure 14.
Figure 14: Checking target connection using Waijung
There is a trick if waijung.checkTargetConnection is not working. Type waijung then press Tab button from the keyboard, it will display all possible functions using Waijung as shown in Figure 15.
Figure 15: Waijung functions
Following are the recommendations which users need to follow
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| GPIO pin | 0 to 15 | Select GPIO pin to attach interrupt. |
| Trigger type | Rising edge--Falling edge--Both edges--Low level--High level | Select the interrupt trigger. |
| Interrupt priority level | Auto--Level 1--Level 2--Level 3 | Select the priority level of the interrupt |
This block can be used to set up an Interrupt Service Routine (ISR) that could be triggered by an input signal to one of the digital pins.
Depending on the input trigger configuration, when the specified trigger conditions are met the block will output a logic ‘true’ signal that could activate a function call subsystem in Simulink.
Previous : Digital Input Block
Next : Timer Interrupt Block
Demo file : sp32_gpio_interrupt_demo.slx
This demo shows how to use the GPIO Interrupt Block. A simple GPIO toggle function for the GPIO2 is implemented using Digital Output Block. This function will be invoked in every rising edge signal on GPIO5. GPIO4 pin is used to generate a square-wave pulse to test the the GPIO5 pin.
The digital output pin (GPIO2) should be connected to a LED to observe the status of the pin.
The status LED (GPIO2) will be changed in every 1s period.
Previous : Digital Input demo
Next : Timer Interrupt demo
Demo file : esp32_uart_hostpc_target_demo.slx
This demo shows the UART communication between the host pc and the target ESP32 using UART Blocks. The user can send the string data (commands) to control or quarry data from ESP32 via COM port.
In this demo, the Docklight software is used to monitor the transmitted and received data from the host computer. The software can be downloaded from this link https://docklight.de/downloads/. The serial port configuration for this software is as below.
The transmitting data from the host computer
Previous : Timer Interrupt demo
Next : UART two boards demo
This block is used to setup the environmental variables required for Camera Data Receiver Block .
Stream video to Matlab Simulink
Previous : Camera Data Receiver Block
Next : Circular Buffer Block
This tutorial shows how to use a web application to setup the ESP32 WiFi connection in Station mode to send data to a web server. It can be separated in to two steps.
The designing of the web page is described step by step in Develop web application for ESP32 to setup WiFi Station mode.
Refer Webapp publishing and Exporting to ESP32 sections to get a better understanding about publishing a web application on Aimagin Connect and export those web apps to ESP32 Aimagin Connect server.
The final web page is as below
The procedure for this tutorial is as follows:
First the ESP32 should be initialized the WiFi in Access Point mode to initialize the Aimaigin Connect server. Then the user an be able to access the Aimagin connect server and configure the WiFi configuration using the created wep page in ESP32 for Station mode to connect to the internet to send the data to a server. After submitted the configuration data and logout from the Aimagin connect the ESP32 will get the WiFi configuration data from the database and switch the WiFi mode from Access Point mode to Station mode. Then the ESP32 connect to the internet and send the data to the target server.
Following figure shows how to setup the WiFi in AP mode
In the Subsystem the Aimagin Connect Server is setup and once the user is logged out from the server the output status from the Aimagin Connect server block goes to 0 and then the Aimagin Connect server stops. Then the SSID and Password data is acquired from the database which the user configured using the web page in the database subsystem as follows.
Databse subsystem:
In sending data to the server subsystem some dummy data is sent to the target server as in the following figure.
The results of the sent data to the server is as follows
The Simulink model file can be found below
Previous : Automatic Logging of data to Google sheets from ESP32
Next : Scheduling mechanism in Waijung 2
Following example is based on retrieving the data from the selected table in the database. For this example, consider a database table with two columns (ID and name) and the web page which has two components; a drop-down menu and a text field. The drop down menu is used to select the ID. The content of ID drop down is automatically populated with ID data from the database. The Name text filed content automatically shows the corresponding name according to the selected ID, using change event callback. This example can be divided in to two sections.
To create a table in the database, go to SQLite under system settings.
Then go to create as in the following figure.
Then name the table as 'example' an add two columns ID and Name to the table and update the table as follow.
Next the data should be added to the table. For that go to insert to add data to the table.
There are two records in this table. For the first row ID: 1 and Name: Mr.A and for the second row ID: 2 and Name: Mr.B as in the figure.
Now creating table section is completed. Next task is to design the web page.
To design the web page, go to Aimagin Connect under System Settings. Then add a new page to the project and give a name to the page as in the following figure.
Then add the required components from the components pane. For this example, there are two main components; drop down menu and a text field. In addition to that put those two components under a container and add the text component under a row component and a column component as in the following figure. Change the label of the drop down menu in Parameter section to ID and the label of the text field to Name. And change the ID of the drop down menu and the text field as in the figure.
To automatically add the required ID numbers to the drop down menu, a callback function should be required. Initialize following function to the init callback to add the ID numbers from the database.
The ID data from the database should be saved as an array to add them to the drop down menu using 'setParameter'. The ID data can be acquired from the database using 'AmgCnt.SQLite.read.all'. The source code is as follows.
var id_array = [];
var dropid = this.id;
AmgCnt.SQLite.read.all({
sql: "select ID from example ",
params: []
}, (res) => {
if (res.rows != undefined) {
for (var i = 0; i < res.rows.length; i++) {
id_array[i] = res.rows[i].ID;
}
setParameter(dropid, 'Options', id_array);
}
console.log(res);
}); Next add a function to change callback of the drop down menu to get the name of the person which corresponds to the selected ID number and show it in the text field when the selection of the drop down menu is changed. The callback function is as follows. The selected data in the drop down menu can be get using 'getParameter' and show the corresponding data in text field using 'setParameter'.
The source code for change callback function is as follows.
AmgCnt.SQLite.read.get({
sql: "select * from example where ID = ?",
params: [getParameter('dropId', 'Value')]
}, (res) => {
if (res.row != undefined) {
setParameter('txtName', 'Content', res.row.Name);
}
console.log(res);
});
In the callback function, first get the corresponding name from the database using 'AmgCnt.SQLite.read.get' function. Add the required SQL to the function. For this example write the sql to get data which is related to the selected ID value. After that, the acquired data should be displayed in the text field. For that, if the data is available display the name of the person using the 'setParameter' function.
If the web page is previewed, it should be as in the following figure.
download all demo files: Led7s4d.7z
This chapter discusses the use of display devices such as LCD display and numeric display (7-segment display) using digital I/O along with STM32DISCOVERY and Waijung blockset
7-segment display consists of 7 LEDs which are arranged in trapezoidal or hexagonal shape as shown figure below. 7-segment comes in many colors and sizes in the market including one digit number, two digit number and four digital number which are widely used. Display information such as temperature, pressure, clock time can be seen easily with the help of 7 segment display.
Figure 1‑1: 7-segment display with common cathode and common anode
7-sergment display can be categorized into two types i.e. common anode and common cathode. Decoding for 7-segment display is shown in Table 1‑1 for common cathode. Supply voltage is set to be logic HIGH to turn ON the LED.
Table 1‑1: Decoding of 7-segment display for common cathode configuration
It is left as an exercise for the reader to make a decoding table for 7-segment display if the configuration is common anode.
Figure 2‑1 shows two aMG LEDs4d board which includes a 4 digit numeric display and 7 segment display which has a common cathode configuration (LTC-4727 JS series of LITE-ON. Figure 2‑2 shows the use of aMG LED7s4d with STM32F4DISCOVERY.
Figure 2‑1: aMG LEDs4d board [1] and pin positioning [2]
Figure 2‑2: 7-segment display using STM32F4DISCOVERY
Purpose
Figure 2‑3: Subsystem block for 7-segment display
The subsystem consists of multiport switch for selecting values in order to turn of the LEDs on the 7-segment as per Table 1‑1. For example, when input port is set to 3, multiport switch will send the value 0x79 or 1111001 to the output port. Default values for the LEDs is set to be 0x7E and there are 10 multiport switches available.
After creating a Simulink model for the 7-segment, numbers are shown from 0 to 9 (up-counting) with each second incrementing the counter. For accessing the Counter Block, user need to go to Simulink >> Waijung Blockset>> Misc. Use the number to display on 7-segment. The counting will keep on repeating.
Figure 2‑4: Simulink model for the experiment of single digit 7-segment
It is left on the user to find the answer if someone wish to do down-counting i.e. 9, 8, 7,…, 0 instead of up-counting.
Purpose
Download the program as shown in Figure 2‑5 in STM32F4DISCOVERY. The program will count from 00 to 99 and counter will increment after every 1 second. Simulink model divides this task in two parts. In part A, the numbers from 0 to 99, the value of Counter Block is split. For example, 15 = 1×10 + 5. So index 0 of multiport switch is 5 and the first index is 1.
In part B, its function is to select the data to the subsystem block and the active common cathode by using counter limited block (upper limited: 1, sample time: 0.005) as a reference. If the value of the counter limited block is equal to 0, the subsystem block will display 5 and then the port K5 of a 7-segment will be activated. Therefore, a 7-segment will display 5 at the first digit. On the other hand, if the value of the counter limited block is equal to 1, the subsystem block will display 1 instead and the port K4 of a 7-segment will be activated and it will show 1 at the second digit, as shown in Figure 2‑6. For example, by operating the counter limited block at 200 Hz, the observer will obtain 15 at the 7-segment.
Figure 2‑5: Simulink model for the experiment of two digit 7-segment
Figure 2‑6: 7-segment representation for double digits
This experiment is the application of STM32F4DISCOVERY to be used as a digital voltmeter by using an analog-to-digital converter module in order to obtain the voltage from an adjustable resistance and the obtained voltage will be displayed on a 7-segment. Moreover, the user can adjust the decimal position by using a switch. For example, the displayed value of 2.564 V will be displayed as 2.56 and 2.6 by applying the switch button once and twice, respectively.
A Simulink Model, shown in Figure 2‑7, is used for a voltage measurement and its value will be displayed on a 7-segment. It is consisted of many subsystem blocks as shown below.
Figure 2‑7: Simulink model for creating digital volt meter
- Display Mode = 0 with no decimal point. S
- Mode = 1 display with decimal point one position.
- Mode = 2 display with decimal two places.
- Mode = 3 display with decimal point three places
Figure 2‑8: Subsystem model for adjusting the display of decimal places
Figure 2‑9: Subsystem block for factorizing integers
Figure 2‑10: Subsystem model for reading voltage
For a decimal number representation, 7-segment is able to adjust the data into an integer form and then open the LED DP or decimal point in an appropriate position. The value of 1.258 in mode 2 is shown in Figure 2‑11 (two digit decimal 1.258*100 = 125.8) can transform into 126.
For DP, by applying an output at port PD7 and display the decimal digit respected to the mode, the user will obtain 1.26 on a 7-segment.
Figure 2‑11: Digital volt meter using STM32F4DISCOVERY
Tips: from the experiment, the value which is lower than 1 (0.75 as an example) will be displayed as 00.75 for the two digit decimal or 000.8 for the case of one digit decimal. What should we do in order to obtain one zero on a 7-segment?
Download all demo files: clcd.7z
Computer users can read messages or see pictures via monitor such as Cathode Ray Tube (CRT), Liquid Crystal Display (LCD) and high resolution Light Emitting Diode (LED) monitors. It is not feasible to connect embedded systems such as microcontroller with big screens.
LCD display module as shown in Figure 1‑1 display simple text such as status of the sensor, temperature/pressure of an environment etc. This direct connection is easy to do and energy efficient as well.
The LCD display includes a liquid crystal screen and control display (LCD controller). LCD controller is responsible for controlling the message on the display screen such as line spacing, line breaks and an ON-OFF pixel to represent a character or image. Character and language which is displayed on the screen depends on the manufacturer. For example, Hitachi HD44780 LCD controller supports English as well as Japanese characters [1].The LCDs which are connected to the microcontroller can be categorized into two types i.e. character LCD and image (graphical LCD) as shown in figure below.
Figure 1‑1: Character and graphical LCD
It is worth mentioning that LCD has more features as compared to 7-segment display still it is easy to connect the LCD with the microcontroller as compared to 7-segment, although LCD costs more as compared to 7-segment display.
In Thailand, text LCD controller are more popular and graphical LCDs do not support Thai characters.
Figure 2‑1 shows the experimental set up for using aMG CLCD2, which includes a LCD display of size 16×4 and the board. When connecting the STM32F4DISCOVERY with aMG CLCD2, STM32F4DISCOVERY and aMG F4 Connect2 need to be powered through the adapter for fully functional display (normally STM32F4DISCOVERY is operational when powered through USB).
Figure 2‑1: aMG CLCD2 board
Purpose
In Waijung Blockset block, there is a related module called aMGCLCD2 in the library which can be accessed via Waijung Blockset>> Hardware Modules >> Character LCD. Figure 2‑2 shows the block parameters of Character LCD Setup. GPIO has two ports. One port can be used for sending control commands and other port can be used for sending text.
Figure 2‑2: Block parameters for Character LCD Setup
Now the question comes, how LCD knows where to send the data from the user within the LCD? The answer is simple. User need to mention the coordinates (xpos, ypos). (0, 0) is the point at the top left corner of the screen (which is the starting and reference point) and (15, 3) is at the bottom right corner, which is the last one.
Figure 2‑3: Characteristics of Character LCD Write Block
Character LCD Write Block is a text input block for display and is used for message passing using a two line LCD volatile data storage block. It is located in Simulink Library >> Misc >> Data Storage.
Figure 2‑4: Simulink model for two line LCD display
Figure 2‑5 shows the use of character LCD Write Block in two ways.
In variable ‘str1’, the default text is ‘Hello…’ and message ‘Welcome to Waijung’. Str2 contains number of letters and spaces.
Figure 2‑5: Two line LCD display
Purpose
This experiment will display a text stored in a constant. User need to edit the model and download it again if wish to display data which changes over time such as counting the number or reading and displaying the value of sensor at regular intervals of time. This feature is not available for Character LCD Write Block because the type of the variable.
Print Block, located in the Library >> Waijung Blockset >> Misc serves as a decimal number converter (Double and Float) or an integer. It means that string can be displayed on the LCD. The Simulink model for the example explained above is shown in Figure 2‑6. Following are the settings for Printf Blocks.
Figure 2‑6: Simulink block for color LCD Display
CLCD and LCD display settings are shown in Figure 2‑7 and Figure 2‑8 respectively.
Figure 2‑7: Default settings for CLCD and assigning a string
Figure 2‑8: For color LCD display line
Figure 2‑9: Experimental results for color LCD display
The first two lines shown in in Figure 2‑9 are set to be fixed with no change throughout the experiment. The working of STM32F4DISCOVERY starts from line 3. The 4th line reflects the changes in the voltage when the value of variable resistor is changed.
Purpose
Simulink model shown in Figure 2‑10 consists of Enabled Subsystem Block which can be found in the Simulink Library i.e. Simulink >> Ports & Subsystems. The program will work within Enabled Subsystem when the switch button in the Enabled Subsystem Block is ON. 4 lines are printed as shown as follows and information about the subsystem block is shown in Figure 2‑11.
Figure 2‑10: Simulink model for displaying text with keypad
Figure 2‑11: Subsystem block information
Download Simulink model into STM32F4DISCOVERY. When SW1 is ON message ‘FiO boards and Waijung Blockset is for anyone” will be displayed. When SW2 in pressed then the message “Embedded system is just a mini computer system” will be displayed on the LCD as shown in Figure 2‑12.
Figure 2‑12: Displaying different messages on LCD by pressing Switch buttons
download all demo files: stepper.7z
This article discusses the use of powered devices such as stepper motors and RC servo motor using STM32F4DISCOVERY and Waijung Blockset.
Stepper motor is a motor with a step rotation. It is a brushless DC electric motor that divides a full rotation into number of equal steps. Step size can be of 0.9, 1.8, 5, 7.5, 15 or 45 degree per step which is controlled by using a Digital Signal Controller (DSC). DSC is also responsible for controlling the direction and speed of the motor. Applications of stepper motors can be found in many ways of life such as printer, motion control positioning system, plotters, slot machines, camera lens etc. Stepper motor has the following features;
Typical stepper motors (two phase stepper motors) can be divided into two categories: Unipolar and Bi-polar as shown in Figure 1‑1 and Figure 1‑2 respectively. A unipolar stepper motor has one winding with center tap per phase. Each section of winding is responsible (switched on) for each direction of magnetic field. A bi-polar motors have a single winding per phase and current in the winding need to be reversed in order to reverse a magnetic pole which makes the driving circuit little complex as compared to unipolar motors.
Figure 1‑1: The external and internal structure of unipolar stepper motor
Figure 1‑2: The external and internal structure of bi-polar stepper motor
Control rotation of Uni-polar stepper motor can be performed by controlling the current which is sent to coil of each phase in certain order. If we want to let current flow in any phase, that phase will have logic state “1”. We can control rotation of stepper motor by 3 approaches.
Single Phase Rotation Control or Wave Drive: To transfer current into coil of stepper motor, one by one as the sequence shown in Table 1‑1 (1 means voltage transferred into the coil, 0 means no voltage). So currents in coils will have same direction. This style will have result as low drive force in stepper motor, so it is not famous approach.
Table 1‑1: Single phase rotation control
Two Phase Rotation Control or Full Step Drive: To transfer current in both coils at the same time and transfer current consecutively as per Table 1-2. This technique gives more current to the motor and motor will have more power.
Table 1‑2: Two phase rotation control
Half Step Rotation Control: To transfer as Two Phase and Single Phase alternatively. This is shown in Table 1‑3.
Table 1‑3: Half Step rotation control
Speed of rotation of the stepper motor axes is based on the time delay. If the time delay is less than the core will rotate faster and if the time delay is more than the core rotation will be slow.
Radio Control (RC) servo motor consists of a small electric motor driving a train of reduction gears. A potentiometer is connected to the output shaft which is responsible for measuring the position of the output. These values are then compared continuously with the commanded position of the radio control and in case of any difference between the output value and the commanded value, error signal is generated which instructs the motor to change its position accordingly. Due to RC servo motor light weight and cheap price, their applications can widely found in small scale robotics, steering of a car etc.
Figure 1‑3: Internal components for RC servo motor
Control devices such as stepper motor can be used to create a high driving torque flow. Microcontroller cannot be directly connected with the motor (as microcontroller pins cannot provide the required amount of current to run a motor) therefore current driver is placed between the motor and the microcontroller. For example, the board aMG Step Motor Driver IC ULN2003 can supply up to 500 mA current for controlling a unipolar stepper motor.
Figure 2‑1: Characteristics and features of stepper motor used for this experiment
Figure 2‑2: Using stepper motor with STM32F4DISCOVERY
Purpose of the Experiment
Figure 2‑3: Simulink model for controlling the rotation of single phase stepper motor
Table 2‑1: Simulink block model for controlling the rotation of single phase stepper
When users download Simulink model into STM32F4DISCOVERY aMG F4 Connect, the LED lights on the board (aMG Step Motor) will run in a sequence. The axis of the stepper motor will rotate at a constant speed (counterclockwise). Users can adjust the values of the Counter Limited Block Sampling time. This section will enable the users how to create Subsystem Block in Simulink for the use of stepper motors. Compared to writing a program in C for Subsystem Block, it is very convenient to do using Simulink as user only need to set the Input and Output ports. Creating and using Subsystem Block for the stepper motor involves the following steps;
Figure 2‑4: Creating Subsystem Block in Simulink
Figure 2-5: Subsystem model for controlling stepper motor (single phase)
Figure 2-6: Simulation model for controlling the stepper motor Subsystem Block
If users want to control the two phase rotation, this can be achieved by fixing the value of the Constant Block as shown in Table 1‑2: Two phase rotation control, Figure 2‑7 respectively.
Figure 2-7: Simulation model for controlling the stepper motor (two phase
If users want to control the phase rotation, this can be achieved by increasing the number of data ports in the Multiport Switch and fix the value of the Constant Block as shown in Figure 2‑8 and Table 1‑3.
Figure 2‑8: Simulation model for controlling the stepper motor (half phase)
Objective of the Experiment:
Figure 2-9: Subsystem Model for Counter Up/Down
For block that is the important part to increase or decrease are Increment Real World and Decrement Real World (Library Simulink >> Additional Math & Discrete >> Additional Math: Increment – Decrement)
From Simulink (Figure 2‑10) set Constant Block Value = 3 to set CntUpdown to count value between 0-3 (note: If want to control half-phase, set Value = 7) and set Sampling Time = 0.005.
Figure 2-10: Simulink Model for rotation direction of stepper motor by push button switch
When Simulink model is downloaded into STM32F4DISCOVERY, then the Digital Input Block will read logic state from SW1 and SW2 (connected to pin PB2 and PB15) every 100ms and then send the signal to CntUpDown Block to control rotate direction. Results will be:
Objective of experiment:
Rotation speed of stepper motor can be performed by time delay in each step. The disadvantage of Simulink model is users are unable to adjust Sample Time of Source Block in the model after downloaded into STM32F4DISCOVERY.
We can set the value of Subsystem Block to start or execute internal program when have external signal by put the Trigger Block in Subsystem Model (Fig. 2-11)
Figure 2-11: Adding Trigger Block in Subsystem Model
Add Digital Input Block to read signals from DIP Switch and Multiport Switch to select signal from Pulse Generator Block that have a pulse width 50% and setting period values as in Figure 2‑12.
Figure 2-12: Simulink Model for adjusting rotation speed of stepper motor with DIP switch
User can set DIP Switch as shown in table (in the above figure) to adjust rotation speed. For example, when all positions are set to OFF, CntUpDown Block will work every 0.005 second (positive edge signal will occur every 0.005 second) and stepper motor will rotate when SW1 switch is press and hold. When set DIP Switch all “ON”, system will go to Default condition then CntUpDown Block will be working every 0.02 second therefore the stepper motor will rotate slower.
Objective of experiment:
To study structure and able to control position of rotor axis with push button switch by rotating the axis 90 degree clockwise when SW1 is pushed and rotate the axis 90 degree clockwise when SW2 is pushed.
Controlling the axis is an open loop system because no signal from the sensor is sent back into microcontroller. Thus the system can know the position of rotor axis by number of steps that has been sent to stepper motor to let STM32F4DISCOVERY identify the current position of stepper motor’s axis. User can add the position calculation part into CntUpDown Subsystem Block (Figure 2‑13)
Figure 2-13: Subsystem Model for count step that sent to Stepper Motor
Position controlling of axis of stepper motor can follow these steps:
StepToGo = Desired Step – Current Step
From the properties of stepper motor in the experiment, Step Angle: 5.625 degree / 64 means motor rotate 1 step the axis will rotate 0.0879 degree, so if we want to rotate 90 degree.
Desired Step = 90 / 0.0879 = 1024 Step
Figure 2-14: Simulink Model for control position of the axis of Stepper Motor
After downloading the Simulink model into STM32F4DISCOVERY, the motor axis will rotate 90 degree counterclockwise or +90. When push reset, the current position will be deleted from memory so the motor will rotate again to the position +90.
Figure 2-15: Simulink Model for control position of axis of Stepper Motor with push button switch
Figure 3-1: Using of Servo with STM32F4DISCOVERY
RC Servo receive digital signal to change the axis’s angle in the form of Pulse Width Modulation (PWM). Position controlling module of RC Servo will check time of signal at state “ON” or pulse width then adjust the position as programmed by its manufacturer. Figure 3‑2 shows the estimated width of ON signal for controlling the SG90 RC Servo with signal period 20ms. If user use other model of RC Servo they should study its detail in datasheet especially its voltage and pulse width.
Figure 3-2: Width of signal ON or %Duty Cycle for control position of RC Servo
In the section Digital Input/Output is described using Pulse Generator Block to generate signal that user can only set the %Duty Cycle in the block. In this section, we will also describe how to use Basic PWM Block to generate PWM using Timer of STM32F4DISCOVERY. User can select Timer and Channel to send signal to external devices such as RC Servo or DC Motor controller and able to configure the %Duty by Simulink.
The basic PWM Block is in Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> TIM that has the properties as given below.
Figure 3-3: Properties setting of Basic PWM Block
Objective:
Figure 3-4 Simulink Model for control RC Servo position by DIP switch
Figure 3‑4 shows Simulink model for control RC Servo position by DIP switch. Digital Input Block read the signal from DIP-SW1 and DIP-SW2 which are connected to PE3 and PE4 respectively. Received signals will be translated to decimal form (between 0-3). Multiport Switch will select %Duty Cycle related to Index and then send to Basic PWM Block.
After downloading the program into STM32F4DISCOVERY, PWM signal will be sent to RC servo. As a result, the motor will rotate to the position of %Duty Cycle of PWM signal. When all DIP switch are at the position “OFF” – rotated to the -90 degree position. When all DIP switch are “ON” – rotated to the +90 degree position. When SW1 is ON then motor will rotate to -45 degree and when SW2 is ON the motor will rotate to the 0 degree or origin.
Problem: If user wants to set RC Servo to be at 0 degree (Pulse Width = 1.5ms), what %Duty Cycle of PWM is needed if signal frequency = 60 Hz?
Answer: Signal = 60 Hz means Period = 16.67 ms. Then %Duty Cycle can be calculate => 1.5ms x 100/16.67ms = 9.0 %
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Figure 3-5: Experiment for control RC Servo with DIP Switch
Objective:
Figure 3-6: Simulink Model for control position of RC Servo with variable resister
Figure 3‑6 shows Simulink model for controlling the position of RC servo with variable resister. ADC read electrical voltage at pin PA5 then that value will be transformed to %Duty Cycle by linear relation equation between ADC Value (0 – 4095) and %Duty Cycle as shown in Figure 3‑7.
Figure 3-7: Linear relation between ADC value and %Duty Cycle
RC Servo will rotate to any position depending upon the voltage value. When resistor is connected to the GND, motor will rotate to -90 degree position (%Duty Cycle = 2.5). When resister is connected to VDD (or 3.3 V), motor will rotate +90 degree position (%Duty Cycle = 12.5). Figure 3‑8 shows the positions of RC Servo at each value of voltage read from A5 pin.
Figure 3-8: Experiment to control RC Servo with potentiometer
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All microcontrollers have multiple pins and each pin is assigned for some specific task. It is therefore very important to know the pin configuration of each microcontroller before using it. Some of the common features of microcontroller pins are as follows.
In order to set each pin’s function, user must set the functionality in the software by setting value in registers (it is similar to setting the functions in machine but machine has buttons or switches, but microcontroller has no button or switch, so we must set them by the software directly into the memory). It is the manufacturer who decides which pin is allowed to do what function(s). Although this document explain how to look pin function of microcontroller of type STM32F4, this technique can be applied to other types of microcontroller as well. Some basic things to note in a microcontroller are:
Figure 1‑1: How to analyze pins of microcontroller?
It can be observed that datasheet plays a fundamental role in finding information about the pins. In advanced microcontrollers, user might need to consult more than one relevant document together to extract the correct information.
Figure 1‑2: To check microcontroller belongs to which family
Figure 1‑3: To see which model of microcontroller STM32F407VG and with how many pins
Figure 1‑4: MCU STM32F407VG pins functionality
Figure 1‑5: To see which pin is 29 on the board
Download demo file Thermocouple_demo.7z
Transducers, which are used for measuring the temperature, are of many types such as RTD, thermistor, and temperature sensing ICs etc. Thermocouples have exceptional properties which are mentioned as follows
Therefore it is a popular device [1] both for daily use applications and industrial purpose, for example, measuring the temperature inside the oven, gas turbine machine, diesel machine, and industrial process.
Some disadvantages of thermocouple are: very less linearity compared to RTD or specific designed IC (those are more sensitive and accuracy). Moreover, output signal of thermocouple is very low (estimated 40 mV/°C for K-Type thermocouple). Users have to use complex signal adjustment circuit for high resolution, signal amplification, signal compensation, etc [2].
Despite of the disadvantages mentioned above, the advantages prevail and they are very popular choice now days.
Thermocouple is a device which is used for measuring differential temperature. Thermocouples are made up of two different metals. One is set to be positive type metal and another one is set to be negative in nature. Table 1‑1 shows the properties of each thermocouple [3]. Each type has different range of measurement.
Table 1‑1: Types and properties of each thermocouples
If we connect two different type of metals as shown in Figure 1‑1, electric voltage that is created in the circuit due to difference of temperature between two points is known as “Seebeck”. The process to convert temperature into electric voltage is given in equation (1).
Figure 1‑1: Working of thermocouple that results from Seebeck phenomenon
Figure 1‑2 shows the principal of general thermocouple. Two lines of metal are connected from the end and another end is left open, having connection to third metal (copper wire). Copper wire is the electrical medium between the two metals and the system which results in an additional connection point. As long as the temperature of the two connections and copper wire are equal, there is no effect on the output voltage (Vout)
Figure 1‑2: Principle of general thermocouple
Following relations govern the principle of thermocouple.
V out = V H – V C ........................................................(1)
V out = α(T H – T C) ....................................................(2)
where;
Thermocouple, which is shown in Figure 1‑2, the output voltage is the function of product of difference between temperature at hot and cold junction and Seebeck coefficient and is expressed in (2). Thus when we know the temperature at the cold junction and output voltage, we can know the real temperature at hot junction.
Considering a simple example, if the temperature at cold junction is 0°C (Tc = 0°C) then Vout = V H. In this case, the measured temperature will be the same as that of hot junction. Referring to the National Bureau of Standards (NBS) which lists the relationship of electric voltage and temperature of each thermocouple with reference to the cold junction at 0°C.
Setting the cold junction at 0°C is not easy in the real world, so if the temperature is not 0°C, we have to know the value of temperature at the cold junction to calculate the measured temperature (at hot junction). Then the output voltage have to compensate this discrepancy. This process is called “Cold-Junction Compensation).
Thermocouples have different types depending on the purpose of use as shown in Figure 1‑3.
Figure 1‑3: Example of K-type thermocouple
Because thermocouple has many good properties as mentioned earlier, so it is very common commodity in many industrial applications. Selection of suitable thermocouple has to consider the following factors:
Figure 1‑4: Popular thermocouples for industries use
aMG Sense-Thermocouple is a module for receiving analog signals from thermocouple and transform them into 14 bits digital signal. These 14 bits digital signal becomes the input of the microcontroller that has a SPI interface having signal conditioning circuit and cold-junction compensate function to make the temperature measurement more accuracy.
Figure 2‑1: Digital temperature measurement circuit, aMG Sense-Thermocouple
General Information about aMG Sense-Thermocouple is as follows.
Applications can be found in general equipment, industries, temperature control system, HAVC vehicles etc.
aMG Sense-Thermocouple, temperature measuring module, has 2 signal connection points. P1 is output signal module which will be connected to the microcontroller through SPI protocol. P2 is signal receiving point which receives output signal from thermocouple. Connections at each point must ensure that poles are correct.
Figure 2‑2: Functions of each connect points on the board
Figure 2‑3: Connection between module and microcontroller
To prevent the failure of the device, following things must be noted.
This module comes with built-in signal conditioning circuit and cold-junction compensator which makes the use of the device easy for the users. Module comes in a small compact size and also have the ability to reduce noise from signal guide from thermocouple. Before the measured data is translated into the temperature values at the measured point, compensation for the difference between cold junction sides must be taken into account. For type-K thermocouple, the relation is given by equation (3).
VOUT = (41.276µV/°C) x (TH – TC) (3)
Where
In this function, when the temperature at cold-junction is changed, the measured value is still accurate. The principle to measure temperature at measure point (-270°C to +1800°C) of this module is that – first measure the temperature inside the chip (-40°C to +125°C) via precise measurement assuming that the value should be equal at all cold-junction points. Then measure the output voltage of thermocouple through ADC module. All the measured values will be used to solve equation (3) to find TH, the already compensated value and transformed to signed binary data. Notice that at some range, the value at hot-junction is lower than cold-junction.
From the principle above, to make highly efficient measurement, we must prevent heat that might affect the chip (temperature should be same in all area of the module) to prevent the measurement error.
Data communication between the module and the microcontroller is uni-directional SPI, as in Figure 2‑4. Read only begin at microcontroller creates logic LOW at CS pin and generate a clock signal at 5 MHz into SCK pin. Module will send processed data at SO pin. The measured value and already compensated value need 14 clock signals. All data need 32 clock signals. The first sent out bit is the 31st bit (sign bit of thermocouple temperature). Error and temperature value will be updated when logic at CS pin is HIGH again.
Figure 2‑4: Protocol for SPI module
From Table 2‑1, measured temperature begins from bit D[30:18] ordered from MSB to LSB bit. D16 is normally in LOW state and will be HIGH if error occurs such as no connection to thermocouple, short circuit between thermocouple and VCC or GND. Reference temperature data has 12 bits begins from D15. If input point + and – of module has no connection with thermocouple, the D31 bit will be 0 and D[30:18] will be 1. Bit D0, D1, and D2 normally is in LOW state. Bit D2 will be HIGH when connector of thermocouple is short circuit with VCC. D1 bit will be HIGH when thermocouple is short circuit with GND and D0 bit will be HIGH if there is no connection between thermocouple and module.
Table 2‑1: Format of output signal from module
Table 2‑2: Example of data read from thermocouple
Table 2‑3: Example of data read from reference point
In these examples, aMG Sense-Thermocouple is used along with aMG Lab Kit – F4 with type-K thermocouple (-270 to +1372).
Devices to be used:
Assemble STM32F4DISCOVRY board and aMG USB COnverter-N2into master aMG F4 Connect 2 board and then connect type-K thermocouple to input of aMG Sense-Thermocouple (check the poles carefully). Use jumper wires to make circuit as shown in Figure 3‑1.
Figure 3‑1: Circuit for experiment 1
Figure 3‑2: Software at MCU
The pin PE3 of MCU board is set to HIGH state in order to cancel other sensors information which were used before. SPI Read Box will read data and store information in 8 bit variable. Thus, if the user wants to read 32 bits data, then user need to have 4 variables for that. First read position is LSB, but if the user wants first position to be MSB then Send Data Box need to be re-arranged as shown in Figure 3‑3.
Figure 3‑3: Rearrangement of data in Send Data Box
From the manual reference [3], it is known that the maximum time to process data is 100 msec so sample time of SPI read is set to update every 0.1 seconds.
Software at host PC is shown in Figure 3‑4. Receiver on PC uses 32 bits variable. To extract the required data bits, Extract Bit Command Box is used. To converse signed binary into decimal, user can use Data Type Conversion box and then multiply by the Gain as in Table 2‑1.
Figure 3‑4: Software at host PC
In this experiment, the same equipment will be used as used in experiment 1 but one additional aMG Sense-Thermocouple board and a thermocouple will be used.
Connect the devices as in Figure 3‑5. These two modules use common VCC, GND, SO, SCK and connect to MCU at the same pins. CS pin of the existing module still uses D12 pin but the new module use D11 pin. Software at MCU is shown in Figure 3‑6.
With the help of Counter Limited and logical operator (NOT), alternatively HIGH-LOW signal is generated between pin D11 and D12 to choose the connection at the module. Logic LOW is used for data reading and logic HIGH is used for not to read the data.
Figure 3‑5: Circuit for experiment 2
Figure 3‑6: Software at MCU
Software at host PC uses Compare to Constant to detect that data coming from which module? If the data is the same, it will sent output data “1” to display the received data.
When the temperature value is being displayed, the user can try pulling the thermocouple out or using a copper wire to short circuit the connection points of VCC and GND and observe the changes at bits 0, 1, 2 and 16. There should be 1 for each test condition.
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Figure 3‑7: Software at host PC
Devices and connections for this experiment are same as in experiment 2 with an addition of aMG CLCD 2 and aMG USB converter – N2 is removed from the circuit. The experimental layout is shown in Figure 3‑8 and example software at host PC is shown in Figure 3‑9. If user wants to have a clearer display of LCD then LCD must be connected to external power supply.
Figure 3‑8: Circuit of experiment 3 and LCD display
Figure 3‑9: Software at MCU
This example describes only idea about software when more than two thermocouples are connected. Let’s assume that there are five thermocouples then software will be as in Figure 3‑10.
MATLAB function box for software at PC side has an sample program to find the mean (average) of measured temperature from each module.
Figure 3‑10: Software at MCU
Figure 3‑11: Software at PC side
download all demo files: AdcDac.7z
Applications of embedded systems are in all domain of life including control and instrumentation system, robotics and electrical appliance. In detecting a physical quantity, sensors play an important role by detecting/measuring a physical quantity such as distance, speed, force, pressure, humidity, light intensity, temperature etc. and then change these properties into the electrical signals which are mostly analog voltage (0-5V) or current (4-20mA).
These physical cannot only be detected by the analog pin of a microcontroller but can also be detected by a digital I/O depending upon the need of application. For example, a photodiode is a device which converts the light energy to current. That current can be fed to analog I/O or digital I/O. If that current is applied to the analog I/O then the I/O pin will read the value between 0-1024 which can be then interpreted between 0-5V by scaling. If the photodiode current is applied to the digital I/O, it will classify it either ‘0’ or ‘1’ based on the threshold defined.
Data received from the sensor or the data which is being processed inside the microcontroller sometime requires the analog to digital conversion or digital to analog conversion. This makes the data fit to become the input or output of certain module. This requires the presence of a module Analog to Digital Convertor (ADC) or Digital to Analog Convertor (DAC) inside the microcontroller. Most of the modern MCUs have these modules and Fio2 STM32F4DISCOVERY is no exception to it.
Users can see the number of channels of analog signals from the data sheet of respective microcontroller. Below the figure highlights the pins for ADC to read the voltage from an external device and DAC to send voltage to external devices.
Figure 1‑1: ADC and DAC modules for STM32F4DISCOVERY[1, p. 14]
Figure 1‑2: Analog channel modules for FiO2 [2, p. 14]
Figure 1‑3 shows the voltage characteristics of ADC. Conversion of voltage range should be between 0V to V REF+ . Power reference voltage should not increase 3.6V and should not be less than 1.8V.
Figure 1‑3: ADC characteristics [1, p. 129]
To read a voltage which is less than 0V (negative) or more than 3.6V, signal conditioning circuit should be used and aMG-SIGCON suits well for this application. Before connecting aMG-SIGCON with the microcontroller [4], it is highly recommended to see the characteristics of aMG-SIGCON from the following website.
http://waijung.aimagin.com/index.htm?amg_sigcon_a.htm
Figure 1‑4 shows the electrical characteristics of DAC module. The maximum output voltage of DAC module is maximum analog supply voltage V DDA – 0.2, where max. V DDA is 3.6V. Operational amplifier is used to reduce the output impedance as shown in [1, p. 137]Figure 1‑5.
Figure 1‑4: Electrical characteristics of DAC [1, pp. 136-137]
Please note that output of DAC cannot be 0 or exactly V DDA. The buffer gap is about 200mV which is the trade-off for not using operational amplifier.
Figure 1‑5: Buffered and non-buffered DAC [1, p. 137]
Regular ADC block converts the analog signal into digital data. Users can select the channels and sample rate (sample time) of ADC module for the blockset in Simulink library>>Waijung Blockset>>STM32F4 target>> On Peripheral Chip >>ADC. Regular ADC block has the following characteristics.
Figure 2‑1: Regular ADC block characteristics
Objective
The sensor aMG Photocell-A is shown in Figure 2‑2. It measures the light intensity. Voltage divider rule can be applied to find the which is governed by the following relationship.
Figure 2‑2: Circuit board for aMG Photocell-A
Table 2‑1:aMG Photocell-A power characteristics
Figure 2‑3 shows a Simulink model for switching the LED. Regular ADC block is used. The working of the model is described as follows;
Figure 2‑3: Simulink Model for LED switching using Light sensor
Digital data from ADC module has 12-bit resolution. It is not convenient to display the values from 0 to 4095 on STM32F4. The values from 0 to 4095 does not give us meaningful information therefore it is better to translate this information from 0 to 3.3V with the help of simple transfer fuction (By multiplying with the gain of 3.3/4095.
Figure 2‑4 shows the relationship between the digital values and the actual output. On the x-axis, the digital values are given and on y-axis the corresponding analog voltage value is given.
Figure 2‑4: Relationship between digital value and actual voltage
In Figure 2‑4, we can see a red line. For example, the value of ADC is 3060 and we want to obtain its corresponding voltages. To get the corresponding voltages, value of ADC is multiplied by the gain factor i.e.
3060* (3.3/4095) = 2.465V
The data processed through ADC can be visualized through the LCD panel available on the microcontroller. This can be shown in Figure 2‑5.
Figure 2‑5: Simulink model for displaying the value of light sensor using LCD display
Figure 2‑6: Controlling the LED using light sensor
Regular DAC block acts via signal DAC1_OUT (pin PA4) or DAC2_OUT pin PA5) for the blockset to control analog output on STM32F4DISCOVERY board. In Simulink library, DAC block can be accessed as Simulink library >>Waijung Blockset >>STM32F4 target >> On Peripheral Chip >> DAC. Regular DAC block has the following features.
Figure 3‑1: Characteristics and settings of Regular DAC Block
Objective
This experiment uses STM32F4DISCOVERY to generate a periodic signal. It has two inputs. The first input is Saw Tooth to pin DAC1 (A4) which has a voltage level between 0V to 1V. The second input is given at pin DAC2 (A5) which has an analog signal frequency of 20 Hz and the voltage level between 0 to 2.5V.
Figure 3‑2: Simulink Model for the Experiment
With the help of the oscilloscope, the signals can be observed. The results are shown below.
Figure 3‑3: Experiment to generate periodic signal
From the example of Regular DAC Block mentioned above, we use a signal source from Simulink >> Source and its limitation is depended on elapsed time during the trigonometry function calculation. For instance, a sinusoidal waveform of 20 kHz which its period is 50 micro second need to compute the voltage every 5 micro second in order to obtain 10 samples of voltage per pulse and therefore, it may cause the other system not working. Hence, we should use Arbitrary Waveform Generator instead in order to generate high frequency signal that will be discussed later.
The Arbitrary Waveform Generator developed by Aimagin allows the user to define the dataset. To create a model of the desired signal, the information is downloaded in the memory of STM32F4DISCOVERY. The Arbitrary Waveform Generator has the potential to create a high frequency signal (up to 2MHz frequency from ADC module). Following are the steps to generate a signal from Arbitrary Waveform Generator.
X = 0:1:49; then press ENTER
Y1 = sin(2 × pi × x/50) + 1.5; then press ENTER
Y2 = 4 × (sin(2 × pi ×x/50) + sin(3 × 2 × pi × x/50) + sin(5 × 2 × pi × x/50)/5)/pi + 1.5; then press ENTER
Figure 3‑4: Simulink Model for generating signals using Arbitrary Waveform Generator
Figure 3‑5: Parameters setting for Arbitrary Waveform Generator
Figure 3‑6: Results generated by high frequency analog signal
Objective
Figure 4‑1: Simuink model to read values from analog signal to digital signals
The Simulink model of this experiment consists of two parts: reading the analog input and displaying the results on LCD screen and creating a digital signal using 4 Pulse Generators with a period of 0.001 second (frequency 1 KHz) each and duty cycle of 25, 50, 75 and 99%.
Digital signal is called Duty Cycle Pulse Width Modulation which is a popular technique for controlling the speed of the motor or adjusting the light bulb. The user can generate the PWM signals using basic PWM or Advanced PWM blocks in Simulink library >> Waijung Blockset >> STM32F4 target >> On peripheral Chip >> TIM.
After downloading the program to STM32F4DISCOVERY, pin D15 will send a digital signal with a frequency of 1 KHz. User can select the duty cycle of the digital signal by setting DIP switch as shown in Table 4‑1. Pin D15 is to be connected with an RC circuit which serves as a first order filter for the signal as shown in Figure 4‑2. Signal after filtration will be sent to the LCD for display.
Table 4‑1: DIP switch for changing the duty cycle
Figure 4‑2: Reading Analog Value from Digital Signal
Values of the RC circuit will vary depending on the selection of the duty cycle. For this experiment, the values are taken to be R = 10 Kohm and C = 0.1uF.
Purpose
In this experiment, potentiometer (variable resistor) is used for analog signals. Pin PA5 is configured so that it received analog signals and pin D15 is configured to have a digital input form. Figure 4‑3 shows in the Simulink model which includes the LCD setup and LCD display. PD14 is the digital output which is connected to LED3 which can be act according to the signals on PD14.
Figure 4‑3: Simulink model for analog signals to digital input
After downloading the program on STM32F4 DISCOVERY, the voltage of the potentiometer can be observed on the display LCD. The blinking of LED3 and LED4 is controlled by the following table.
Table 4‑2: Results
Figure 4‑4: Reading digital input signal
To convert an analog signal to digital one, sampling time plays a crucial rule. Sampling time determines at which time the sample should be taken. For example, if sampling time is set to be 0.01 sec, this means that the signal is measured and converted the analog to digital signal after every 0.01 second i.e. 100 Hz (Sampling frequency).
Choosing an appropriate sampling rate is very important. If the sampling rate is very less then error introduced in the system will be more. If the sampling rate is very high, then it requires high computation power and memory [7]. In order to have an appropriate sampling rate, Nyquist criteria determines the frequency. According to the Nyquist theorem, the sampling frequency should be twice the frequency of the signal. If there are multiple frequencies in the signal then sampling frequency should be twice to the maximum frequency of the signal [8].
One thing should be remembered that the sampling frequency also depends on the requirement of the application. If the bandwidth requirements are not strict then there is no harm to exceed Nyquist sampling frequency. Nyquist theorem only tells the minimum requirement of the sampling frequency. If the sampling frequency is below Nyquist theorem, then signal cannot be reconstructed. In some applications, the sampling frequency is taken to be 20 times the maximum frequency of the signal to be very close to the original signal.
In this experiment, the sampling time of ADC module is taken to be 0.01 second (which can be changed to desired value) and this sampling time is used to read the analog sinusoidal waveform with different frequencies of 5Hz, 20Hz, 50Hz and 60Hz (User can use Function Generator to create the above mentioned frequencies instead of using Regular DAC block y setting the minimum and maximum voltage of 0.5 – 2.5V). Following are the steps to accomplish this experiment.
Figure 4‑5: Analog to Digital Conversation
Figure 4‑6: Simulink model for reading voltage
Figure 4‑7: Sample rate selection for Simulink model
Table 4‑3: Sample rate selection for the host
Figure 4‑8: Waveforms of 5, 20, 40, 50 and 60 Hz with sampling frequency of 100 Hz
The above figure shows the waveforms for different frequencies from 5 Hz to 60 Hz. The sampling rate for all the waveforms is set to be 100 Hz. From the Nyquist criteria, it is known that for 60 Hz waveform, 100 Hz sampling frequency is not high enough to reconstruct the signal. For practical purpose, the sampling frequencies are taken to be 20 times more than the maximum frequency of the signal.
Download demo file datalogger.7z
In this article, description about how to read and write data on flash memory using a microcontroller is given. The limitation of this technique is that only data less than 1MB can be stored thus not suitable for big data processing.
SD cards are used for storing data (storage is non-volatile) and can retain the data in the memory without power as well. SD cards are often used in mobile phones, digital cameras etc. There are many types of SD cards available in the market. SD cards can be divided into three types which are shown in Figure 1-1.
Figure 1-1: Identifying the types of SD cards
Figure 1‑2 shows the class of SD cards based on their speed of data transmission so that user can select these SD cards based on the requirement of the application whether the user is using it for recording high definition (HD) movie or general purpose storage.
Figure 1-2: General Information on SD and Micro SD Cards
SD cards are compact and small is size and for this reason, they are the favorite choice to be used as a data storage device in embedded systems. SPI communication can be used to receive data from the SD card but STM32F4ISCOVERY has a STM32F407VG microcontroller which has specific management system of Secure Digital Input/Output (SDIO) [1]. Pin description of SDIO interface is given in Figure 1‑3.
Figure 1-3: Input/Output port SDIO Interface
Each pin has the following functions.
Pin SDIO_CMD is for sending commands by CE-ATA to SD card and have the default settings of the SD card.
As a SDIO interface, the cable has a multi-bit SDIO interface so that it can transfer data faster than the SPI interface. Figure 1‑4 shows the pin layout of the SD card when it communicates with SDIO interface using 4 bits.
Figure 1-4: Pin Layout of SD, MiniSD and MicroSD Card in SDIO mode
Data logger is a device which is used to store data from various sensors. Generally data logger devices can be connected to the sensors directly. Data can be saved into the memory of SD card with the time stamp and users can access the data from the data logger later. Computers can also be used for reading the data from the memory and display it in various forms such as tables, graphs etc. Data logger devices can also be connected to the computers directly.
Figure 2-1: Applications of embedded devices to data logger
Data logger devices can be used in a number of ways such as recording the humidity of certain place or the temperature or the location of the vehicle using GSP etc. Data logger devices can operate in a stand-alone manner and able to read the signals from the sensor and save the information in their memory without the use of any additional software or peripherals to the computers. They are designed in such a way so that they can be installed easily where required.
Application of an embedded data logger is presented as an option because of their small size. Microcontrollers like STM32F4 family can receive the signals in a number of ways for example from analog to digital module, I2C, SPI UART, etc.
This article explains how to use the data logger block and how it can be used to record the voltage reading from ADC module into the memory of SD card and read the data from the SD card on the computer with the help of Microsoft Excel and Notepad ++. MATLAB is used to obtain the graphs.
For this experiment, a user must know the socket available for MicroSD card in aMG F4 Connect board and aMG CLCD2 which is shown in Figure 2-2.
Figure 2-2: Sockets for MicroSD card
If the user has a separate SD card reader, then it can be connected to STM32F4DISCOVERY as shown in Figure 2-3.
Figure 2-3: Circuit for connecting MicroSD card
Note that Waijung blockset is not compatible with SD card SPI model. Users can read and write to SD card module that works with SPI interface.
In Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> SDIO contains blockset for recording on SD Card.
Figure 2-4: Characteristics and features of the Data Logger Block Ascii.
Aim
Figure 2-5: Simulink model for storing/writing the data in SD card
In this example, experiment will be conducted for logging the Ascii data logger which is actually a signal from pin PA5, PA6 and PA7 to the SD card. Sampling will be done every 0.5 second. Download the model into STM32F4DISCOVERY. The red light will flash (symbolizing error), if there is no SD card.
Figure 2-6: Insert SD card in the respective socket of aMG F4 connect board
When user inserts the SD card into the aMG F4 Connect or aMG CLCD2 (as shown in Figure 2-6) for recording the data on the SD card, the green LED starts flashing (symbolizing success). With the help of a computer or laptop, open the file as shown in Figure 2-7. A word of caution is, whenever the SD card is inserted or removed, the board should be powered off.
Figure 2-7: Recorded data from three pins and displaying it using Microsoft Excel
Figure 2-8: Simulink Model for real-time data recording on MicroSD card
Data / time Subsystem Block module is used to read the digital clock using I2C serial communication. Real-time readings are converted into String text format.
Figure 2-9: Subsystem Block module for reading the time from a digital clock
Figure 2-10: Devices used in the experiment are data on the SD card and digital clock module
When it comes to SD card, with the help of computer or laptop, browse the file and open it with Mircosoft Excel. File will be containing data similar to Figure 2-11.
Figure 2-11: Information containing date, time and readings from the three channels
High bandwidth storage applications such as signals from the brain or muscles or the application which requires higher sampling rate (greater than 1kHz) requires high speed mode of the data logger. For such purpose, the transmission of the SD card should be fast enough (class 4 or higher type of SD cards). Sometimes, the Ascii characters storage may not be suitable because the CPU requires more processing time.
So in the SDIO Waijung Blockset block has special support for high speed data writing on the SD card. The Ascii and the binary logging requires the installation of Notepad ++ so that the users can see the data in binary format.
The information should be used as a Binary File Notepad ++. Users can Download and install it from http://notepad-plus-plus.org/download/v6.6.8.html HEX-Editor plugin, which includes the following steps.
After you install Notepad ++, select the Plugins >> Plugin Manager >> Show Plugin Manager and follow the Figure 3-1.
Figure 3-1: HEX-Editor plugin installed on windows Notepad ++.
Plugin Manager window will appear, select the first tab ‘Available’ and check HEX-Editor and click on install (computer must be connected to internet in order to install the plugin) and is shown in Figure 3-2.
Figure 3-2: How to install the program HEX-Editor.Plguin of Notepad ++.
Figure 3-3: Binary data display in Notepad++
Figure 3-4: Binary data in Notepad ++ program with HEX-Editor plugin
In Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> SDIO contains blockset for recording data in a high-speed SD card. This includes indicator for SD card as well.
Figure 3-5: Characteristics and properties of a High Speed SD Card Block Ascii
Setup involves consideration of the following points.
Condition
For example, to calculate the speed of the SD card;
If user wish to save data that contains 32 bit counter, data received from ADC 2 channels will be of 8 bytes (4 byte + 2 byte + 2 byte) and use 50 microsecond per sample to save the data. So the data writing speed will be 8 bytes per 50 microseconds or 160000 bytes per second.
File size calculation
Let N be the number of data to be recorded, thus the size of the File = N × record size.
To calculate the amount of time required to save the data.
Let N be the number of data to be recorded, so the time needed to record (s) = N × sample time.
The indicator
Upon completion of the data recording, users can view the recording including the SD Card Error in the MSG.TXT.
SDIO has a block which deals with the saving of data to the SD card. Properties of Data logger and high speed SD card write are described in Table 3‑1.
Table 3-1: Difference between Data Logger with High speed SD card write
Aim
Figure 3-6: Simulink model for storing data on SD card
Figure 3-7: LED indicators on the SD card
After inserting the SD card into the respective socket, download the model into STM32F4DISCOVERY. Users can observe the LED indicators as shown in Figure 3-7.
Figure 3-8: Message in MSG.TXT when writing/recording is finished
Figure 3-9: Data recorded in Data0.txt
Figure 3-10: Data recorded in the last Data0.txt.
If the user removes the SD card before LED Progress (green) start blinking at 0.25 Hz then following message will be displayed (as shown in Figure 3-11).
Figure 3-11: MSG.TXT messages in case of errors during data recording
Aim
Figure 3-12: Simulink Model for saving binary data to SD Card at high speeds
After the user puts SD card in the socket, download the model into STM32F4DISCOERY, data can be viewed from MSG.txt. The recorded data can be seen from Figure 3-13. The data is written at a very high speed i.e. 1 million bits per second.
Figure 3-13: MSG.TXT contains binary text after writing process is complete
For reading the saved binary data, the user should use Notepad++ program at HEX Editor plugin as shown in Figure 3-14. Format of each set is a value which is obtained from 4 channels of ADC. Each channel has 16 bits or 2 bytes (so in total there are 8 bytes), 4 bytes are used for bit indexing and 4 bytes are used to identify dataset.
Figure 3-14: Format of binary data recorded in the first period
Users can observe the final data set recorded from the index 0x0F423F or 99,999,910 as shown in Figure 3-15.
Figure 3-15: Final binary recorded data
In this example, the size of the file is:
N = 999,999 and the data size per sample = 12 bytes.
Therefore, the file size is equal to 12 x 999,999 = 119,999,988 bytes or 11.44 Mb.
Note 1 kB = 1024 Byte, 1MB = 10242 = 1,048,576 Byte.
Aim
In case, user wants to stop data recording, user can send signal (data) for example external input signal from Digital Input Block to STOP port of High Speed SD Card Write Block.
Figure 3-16: Simulink model for aborting the recording process on SD card with push button
After inserting the SD card into the socket, download the model into STM32F4DISCOVERY. It will start recording the data and the LED indicator (busy process) will flash at a frequency of 10 Hz. The user can press the blue button (which is actually pin PA0) to stop the recording process.
The LED indicator will start flashing at a rate of 0.25 Hz. The user can then remove the SD card. User can see the recorded data in the MSG.txt file and is shown in Figure 3-17.
Figure 3-17: Results recorded after manual stop
This examples shows that the user cannot set certain dataset (because of switch pushing time). Figure 3-18 shows the index value from Counter Block (named RecordID) which is compared to the number of dataset that has been set. User can set many values by adjusting the DIP switch.
Figure 3-18: Simulink model for the data stored on the SD card when stop with DIP switch.
The position of the DIP switches will determine the length of the data which will be recorded from the dataset.
Table 3-2: Position of switch for specified number of data
I feel that in Table 3-2 one set of 12 bytes predict the size of recorded data
Opening .bin file on Notepad++ may cause problem in program memory in case the size of the file is too big (>1GB). MATLAB can be used to open such big (.bin) files and can transform data to decimal number and arrange the data in matrix/array format. Now the data is ready for further processing such as graph plotting etc.
MATLAB has set of instructions in order to read data from the binary file and users can get more information from the following link in which data is read from DATA0.BIN file which has a size of 1.11 GB. The process is shown in Figure 4-1.
http://www.mathworks.com/help/matlab/low-level-file-i-o.html
Figure 4-1: MATLAB window to set the instruction for reading .bin file
fopen command is used to open a binary file. fread is used to read the file which is open in the first line of the command. The parameters of the fread are the FileID and the way the file should be read i.e. (6, 10000000) and converts the data into unit16 data format and finally storing the information in a variable A. It is worth mentioning here that the way the file should be read must be the same the way the file in written in terms of type of information else the readings will be varied.
Figure 4-2: Description about fopen and fread functions
Data read form the command fread is stored in a variable A and MATLAB can be used for data graphical representation as in Figure 4-3.
Figure 4-3: Graphs from data read from ADC channel 4
Aim
Download the model as shown in Figure 4-4 on STM32F4DISCOVERY board. The model will take readings from the ADC module channels 4 to 7 every 10 msec. The readings obtained from channel 4 and 5 will be converted to hexadecimal or raw data in voltage and the readings obtained from channel 6 and 7 will be saved as raw data.
Figure 4-4: Simulink model for storing binary data in various formats
When it reaches 1,000,000 (which is the total size of the data), the user can remove the SD card from socket and can observe the results as in Figure 4-5 using Notepad ++.
Figure 4-5: Recorded results
One dataset contains the values read from AN4 and AN5 (4 bytes data saved as single), AN6 and AN7 (2 byte data saved as unit16) and value from RecordID block (4 bytes saved as unit32).
Since one dataset contains different data types (single, unit16, unit32), Figure 4-6 shows the MATLAB instructions to read file from .bin file stored as different data type and save them to variables AN4, AN5, AN6 and AN7 for which are basically the magnitudes of voltage of channel 4, 5, 6, and 7 respectively.
Figure 4-6: Set of instructions for reading data from a .bin file
When the user will type the following lines of command, the graphs will be plotted for each ADC channel (from 4 to 7) between data read and time.
subplot(2,2,1),plot(n*1e-6, AN4),grid <Press Enter> subplot(2,2,2),plot(n*1e-6, AN5),grid <Press Enter> subplot(2,2,3),plot(n*1e-6, AN6),grid <Press Enter> subplot(2,2,4),plot(n*1e-6, AN7),grid <Press Enter>
These MATLAB commands will show the graphs of the deta read from various ADC channels and they are shown in Figure 4-7.
Figure 4-7: Graphs of the data read from ADC channels 4 to 7
This documentation will show the user how to use the example demo files provided with the Waijung2 block-set
It is recommended that you copy a demo file and built it in a different folder than the original distributed demo folder. This will keep your original demo file unaffected while you evaluate demo files.
All demo files are located at: [waijung2_installation_directory]\waijung2\targets\esp32\demo
Move the Current Folder of Matlab to the directory where you want to build the demo.
Type this command in the command window: status = copyfile('D:\waijung2_installation_directory\waijung2\targets\esp32\demo\digital_input_demo', pwd);
The command will copy the files in the "[waijung2_installation_directory]\waijung2\targets\esp32\demo\digital_input_demo" folder to the current working directory.
Now you can open the file, build the source code, and upload the program to your ESP32. Your original demo file will not be affected.
Previous: Where to go from here?
Next: Digital Output demo
Download all demo files: DigitIO.7z
Typical applicatons of microcontroller involves the tranfer of data to and from the MCU to external device. Figure 1‑1 shows a microcontroller which can be used for transfer of information. Data transfer can be achieved by utilizing input and output pins (I/O pins). Input pins are responsible for receiving the information from the external devices which is then sent to the memory for storage or/and processing. Output pins are responsible for sending information to the external devices. This information may come either from the memory or by processing the information within MCU.
Figure 1‑1: Transmission and reception of data between microcontroller and external device
Digital I/O is a form of a signal which only have two states or logic levels.
So basically Digital I/O transfer/receive data to/from an external device which is binary in nature. Digital output is used to control devices such as frame relay or LED lamps that requires only turn on and off signals. Digital input is used to read data from a device such as switch or button that is turned on and off. (In contrast there is also an Analog I/O).
Now the question comes, how we can classify logic level low and logic level high? The answer to this queston is very simple. In electronics, if the voltage level is above certain level, it is classified as low and if is below certain level, it is classified as low. Figure 1‑2 shows the digital logic levels for STM32F4 (STMicroelectronics, DS8626: STM32 F407xx Datasheet-production data [Online], 2013, p. 110).
When using the Transistor Transistor Logic (TTL)
When using the CMOS technology, logic LOW and HIGH are determined based on power supply voltage V DD. For example when V DD = 3.3V
For determining the logic levels of a microcontroller, datasheet must be referred.
Hysteresis refers to the difference in the voltage levels between the detection of the transistion level from high to low and vice versa. Hysteresis is very useful technique to overcome the issue of noise. If we define a simple criteria that above 0.5V is high and below 0.5 is low then becuase of noise effect, a 0.49V signal can go to 0.51V thus logic is inverted from the original. Hysteresis gives protection and robustness against such surges. Compared with TTL technology, it gives a range of voltages to be LOW or HIGH.
Figure 1‑2: Digital logic levels for STM32F407xx
Each pin of STM32F4 can be characterized as one of the three types i.e. Pull-Up, Pull-Down and Floating (In addition, some pins are particularly 5V Tolerance. Users need to refer to the datasheet of specific MCU to see if it is 5V tolerance).
Figure 1‑3 shows a pull-up input which is basically is a pull-up resistor connected to VDD or power supply. Pull-up circuit serves the purpose of reading the status automatically in the microcontroller. If pull-down is disconnected then the state is HIGH i.e. “1” all time and if it is connected then the state is LOW i.e. “0” (Active Low). When the switch is pressed then MCU pin goes LOW. Circuit pull-up is better as compared to circuit pull-down as former is more robust to noise.
Figure 1‑3: Pull-up circuit
Figure 1‑4 shows the condition when the pull-up resistor is disconnected from VDD and pull-down resistor is connected to the ground while reading the automatic status from MCU. For the given condition, the circuit will read LOW i.e. “0” all the times and when the switch is pressed it will start reading HIGH “1”.
Figure 1‑4: Pull-down input circuit
Setting pin value to floating has the same idea as pull-up / pull –down but no internal pull-up and pull-down resisters is required. User must connect the pull-up or pull-down externally so it is suitable for some device that already has external Pull-Up or Pull-Down.
The output of STM32F4 are of two types i.e. Push-Pull or Open-Drain. User can choice either of them.
STM32F4 can be set as a Push-Pull output. Internal circuit of microcontroller has two types of MOSFET: the P-MOS that connected between V DD and output pin for transferring current (Source Current) and N-MOS that is connected between output and ground for receiving current (Sink Current). This is shown inFigure 1‑5. The automatic connection control can described below:
From Figure 1‑5, we can see that when connecting a LED between output pin and ground, a resister is used to limit the current. LED will work when output state is “1” (Active High Output). Because of the output has voltage level VDD so the current can flow from microcontroller through LED to the Ground.
Figure 1‑5: Push-Pull output circuit current for sourcing system
When connecting a LED between output pin and external V DD, resister is used for limiting the current as see in Figure 1‑6. LED will work when output state is “0” (Active Low Output) because the current can flow from V DD through LED to output pin (Ground)
Figure 1‑6: Push-Pull output circuit current for sourcing system
The advantage of Push-Pull output is that it can quickly change its state, so it is suitable for such a situation which requires high frequency switching (e.g. visible light communication [4]) and it can directly transfer current to device. The disadvantage of this type is the limitation of current source/sink. User must study pin’s maximum current and voltage values from datasheet of each microcontroller. These information are very important to prevent device from damage and to improve the system reliability. For example, each pin of STM32F4 can sink/source maximum current at 25 mA except PC13 – PC15 can sink at 3 mA [1, p.77] and can sink/source maximum of all pins not more than 150mA as shown in Fig 2-7. Thus when bias the LED with Push-Pull I/O (assume that VDD = 3.3 V) we can use R = 660 Ohm (from R = V/I = 3.3/5m = 660) to limit current at 5mA that enough to make the LED bright and not exceed the 25mA maximum value.
Figure 1‑7: STM32F415xx-417xx Absolute maximum ratings: Current characteristics [2, p. 73]
When setting the output of STM32F4 to Open-Drain, internal circuit in each pin of microcontroller will be controlled automatically as below:
So the Open-Drain output must connect to external electric source Vext as shown in Figure 1‑8 that the device will work at output state “0”
Figure 1‑8: Open-Drain output circuit
Since the Open-Drain circuit doesn’t use power from microcontroller, it can be advantageous because devices are using external power which can have a voltage might be higher than V DD. However user must be careful about maximum current must not exceed 25mA. Furthermore this type is suitable with bus system such as I2C too.
Experiment of digital I/O uses basic devices such as LED to display digital output state, switch button (ON-OFF), and dip switch to create logic of input signal to digital input. These devices (LED etc.) can be easily purchased and they are not expensive.
The board aMGF4 Connect2 developed by Aimagin can be used with STM32F4DISCOVERY. FiO2 has 4 LEDs, 3 ON-OFF swithes and 8-pin dip switch as shown in Figure 2‑1.
The board STM32F4DISCOVERY developed by STMicroelectronics uses microcontroller series. STM32F4 number STM32F407V6T6 has 100 pins and able to use digital I/O maximum at 82 pins. It has 6 ports: PA, PB, PC, PD, PE and PH, having 16 pins in each port (except PH, has 2 pins) each pin can be set as output or input. For example, we can set PD1 to be pull-up input and PD7 to be push-pull output (details can be found in the microcontroller datasheet about each pin). The board FiO2 uses the microcontroller number STM32F417IG that has many more pins but the principle is the same.
Be careful that when using STM32F4DISCOVERY, some pins may be already connected with other device on the board so we have to study the datasheet wisely.
Figure 2‑1: Tool on aMG F4 Connect 2 for testing Digital I/O
Figure 2‑2: LED circuit on aMG F4 connect board
Figure 2‑3: Push/Pull switching circuit on aMG F4 connect board
Figure 2‑4: DIP switching circuit on aMG F4 connect board
The blockset used to control digital I/O is in STM32F4DISCOVERY can be found from Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> I/O by Digital Output block. It has the following characteristics as shown in Figure 2‑5.
Figure 2‑5: Characteristics and settings of digitial output block
Purpose
Figure 2‑6: Simulink Model – Testing the blinking of LED 1
Table 2‑1: Simulink blocks used in blinking LED experiment
In setting parameters of Pulse Generator Block there is an important parameter called Period or the period of waveform. Pulse width gives the information that for how long the LED will be in ON state and for how long it will be in OFF state for a given time. For example, user wants to switch on the LED for 1 sec and switch off the LED for 3 sec and this process keeps on going. For the given case, the pulse width can be calculated by using relation below.
% Pulse Width = (Time for which LED is ON) x 100 / Period
Here Period corresponds to switch ON + switch OFF time i.e. 1 + 3 = 4 sec. So the answer is:
= (1) x 100 / 4 = 25 %
We can simulate the Pulse Generator Block as shown inFigure 2‑8. Pulse type is selected as time based, amplitude is choosen to be 1, period is taken to be 4 sec with 25% pulse width. Click on start simulation by clicking on the Run Icon as shown inFigure 2‑7. Double click on the Scope to see the simulated waveform as shown inFigure 2‑8. The user will not be able to see any LED blinking apparently. But the user must think in mind what does this waveform mean and how to interperet this waveform in terms of hardware? The positive pulse means that the connected LED (right now in simulation not connected) will be ON and when there is no pulse then the LED will be OFF. Furthermore user can observe that for 1 cycle, the LED will be ON 25% of the time and will be OFF for 75% of the time.
Figure 2‑7: Understanding three icons of Simulink
Figure 2‑8:Setting the Pulse Generator Block and blinking LED experiment results
When the user is satisfied that in simulation, the program is working well then the next step is to download the program in the target. Downloading of the program to the target can be done either by pressing CTRL+D or by clicking the icon Update Diagram and then pressing CTRL+B or clicking icon Build and Download as shown inFigure 2‑7. If the downloading of the program is successful to the target then LED6 of STM32F4DISCOVERY and LED4 of aMG F4 will be switched ON for 1 sec and switched OFF for 3 sec and this process keep on repeating. Now it is left on the user to do some experimentation by changing the amplitude, period and pulse width and see the effect on the simulated waveform and verify the similar effect on target LED.
Purpose
Figure 2‑9: Simulink Model – Controlling 4 LEDs simultaneously
Table 2‑2: Simulink block required resources
In this simulation, four LEDs are used. These LEDs are switched ON and OFF in a pre-determined manner as given in the table. Let’s assume that we need to complete 8 steps in 2 seconds. It means that each step is for 0.25 sec. When 8 steps are completed, the system will again go to step 1 and this process keeps on happening. If the user observes the steps table carefully thenuser can know that each LED is ON for 0.25 × 4 = 1 sec and for the same time it is OFF. This implies that the pulse width of all LEDs is 50%. Pulse Generator Block has a period 2 sec.
Another information which can be extraced from the table is in the first step only LED1 is on. In second step LED 1 and LED 2 is ON. In third step LED 1, 2 and 3 is ON and in fourth step all LEDs are ON. This means that there is some time delay between these LEDs. Time delay of LED 2 is more than LED1. Time delay of LED 3 is more than LED1 and 2. Time delay of LED4 is more than LED 1, 2 and 3. We can also write that:
For this example, block from Simulink Source Library such as Counter Free Running Block or Pulse Generator Block will be used as controlling signal for open-close output. When external signal is needed (for example: switch) user can use Digital Input Block to receive signal that is in Simulink Library >> STM32F4 target >> On Peripheral Chip >> I/O.
For Blockset controlling Digital I/O of STM32F4DISCOVERY board, go to Simulink Library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> I/O. Digital Input block and it has the following characteristics.
Figure 2‑10: Settings of digital input block
Further more users can define a sampling time and enable custom port labels to name the input port according to their wish.
Purpose
Figure 2‑11: Simulink model ON OFF switching of LED with push button
Table 2‑3: Simulink block for contolling LED switching using push button
When user has downloaded model into STM32F4DISCOVERY, 4 LEDs will ON when pressing the SW3 and OFF SW3 is not pressed. So the Jog is programmed so that it always send output when the button is pushed and stop sending when button is not pressed. This scheme is suitable for control manual machine such as crane or lifting machine.
Bouncing is the non-ideal behavior of mechanical switches which creates multiple electric transitions when a single input from the user is entered. It takes some time for the input to reach at a stable state. The bouncing effect is shown inFigure 2‑12. From the figure, we can see that in the begninning the switch is in ON state. When user enter the input to switch it OFF, then it takes around 0.01 to 100 msec before the switch is actually switched OFF. A similar effect can be observed when the switch goes from OFF state to ON state.
Figure 2‑12: Bouncing effect
Bouncing is an undesirable effect so it must be removed when designing a circuit. There are number of ways by which we can avoid bouncing. The process of avioding bouncing is called de-bouncing. The most easy and commonly used technique for debouncing is analog filtering. A resistor capacitor (RC) circuit is used to filterout the rapid changes in the switch output. Depending on the nature of the switch, the values of RC circuit is chosen in such a way that input threshold is not crossed while bouncing is still occuring.
Figure 2‑13: RC circuit for debouncing
Other than hardware techniques available to overcome debouncing, software programming can also help to aviod it. This will eliminate the need to additional RC circuit. In RC block, the user can also set the time interval in Waijung Blockset have Debounce block in Simulink Library: Waijung Blockset >> STM32F4 Target >> On-chip Peripherals >> IO by setting parameter of Debounce block.
Mode can be selected as Normal, Single End and Toggle Latch. The user can change working mode and observe the behavior of LED when pushing the button and debounce counting. Toggle mode is the program to always send output when push the button at a time, and stop sending when pushes it again. Thus the program should check the status of output, and send new status of output when the button is pushed. The Toggle is suitable for on-off electrical device.
Debouncing block can be added in between digital input and digital output as shown in Figure 2‑14.
Figure 2‑14: Simulink model for LED control using push button (Toggle mode)
Purpose
Figure 2‑15: Simulink Model to switch LED via dip switch
Table 2‑4: Simulink block used to control switching of LED from DipSwitch
In this experiment, switching of the LED is controlle via dip switch1. Pin PE3 is connected to switch block which will be selected according to the conditions. (This is true when input signal is not equal to 0) Figure 2‑15 shows when condition is true, signal from Pulse Generator is used to control switching of LED.
When dip switch is ON then LED will blink for every 0.5 second and when the dip switch is OFF then LED will be ON when SW3 switch is pressed. This task can be achieved with multiple mode of operations such as automatic mode or manual mode.
Purpose
Design a program such that it switches ON one LED in each round from the four LEDs using counter and bit operation (Be able to look Model from digital output demo stm32f4_digital_output_demo.mdl)
Explanation
When the program starts running, the counter is reset after every 500 msec. Counter starts counting from 0 to 2n-1 which is the highest number in counting. It will again count from 0 and the counter will AND it’s output with constant 3 so that the counter value is in interval 0 to 3 only. After that, it uses block compare to constant to assign the switch ON the LED1, LED2, LED3, LED4 when the value of the counter is 0, 1, 2 and 3 respectively.
The following table explains the working of the program. Each step is for 0.5 seconds. When the step 2 is completed, the program is returned to step 1.
Design a driver for LED 4 working as follows.
Question: STM32F4DISCOVERY and FiO2 are with how many I/O pins?
Answer: STM32F4DISCOVERY that use microcontrolller STM32F407VGT6 or use FiO2 that use microcontroller STM32F417IGT6, users can see the information from Datasheet Product Specification. For example the number of GPIO or (I/O pin) of STM32F407Vx is 82 (STMicroelectronics, DS8626: STM32 F407xx Datasheet-production data [Online], 2013, p. 14) STM32F417Ix has 140 pins [2, p. 14]
Figure 4‑1: Shows the number of I/O pins of all STM32F40xxx models
Question: Which I/O pin to be used?
Answer: User should find the type and characteristics of I/O pins from datasheet.
Question: What I/O pins can supply?
Answer: Voltage up to 3.6 V and current not exceeding 25 mA except PC13 and PC15 which can give maximum current of 3mA.
Figure 4‑2: Table shows the maximum driveable current from STM32F4DISCOVERY
(STMicroelectronics, DS8626: STM32 F407xx Datasheet-production data [Online], 2013, p. 77)
(STMicroelectronics, DS8626: STM32 F407xx Datasheet-production data [Online], 2013) STMicroelectronics. (2013, Jun). STM32F407xx Product-Specifications [Online]. Available: http://www.st.com/web/en/resource/technical/document/datasheet/DM00037051.pdf
[2] STMicroelectronics. (2013, Jun). STM32F417xx Datasheet – production data [Online]. Available: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00035129.pdf
[3] STMicroelectronics. (2013, Feb). RM0090: STM32F40xxx Reference Manual [Online]. Available: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/reference_manual/DM00031020.pdf
Saadi, M., L. Wattisuttikulkij, Y. Zhao, and P. Sangwongngam. “Visible light communication: opportunities, challenges and channel models.” International Journal of Electronics & Informatics 2, no. 1 (2013). Available: http://www.cennser.org/IJEI/eiV02N01/ei020101.pdf
download all demo files: I2C.7z
I2C stands for Inter-Integrated Circuit invented by Philip semiconductor now days known as NXP semiconductor. I2C is intended for low-speed data transfer between devices such as assessing low speed ADC and DAC, reading real time clock etc. The EEPROM memory as an I2C communication feature is connected to the system bus and transfers data between the devices. Using only two signal lines as shown in Figure 1-1, which can reduce the number of cables and accessories. It is popular in small embedded systems.
I2C communication uses digital transmission. A bidirectional open-drain line which can transfer data in line with 2 sets of Serial Data Line (SDA) and is responsible for sending the data and Serial Clock Line (SCL) that transmits the clock signal. The speed of data transfer depends on the frequency of the clock (SCL) of STM32F4 (100 kHz bus frequency is considered as standard frequency and 400 kHz is considered fast) [1, p. 575].
Figure 1-1: Connecting an I2C device [2, p. 1]
The signal of the device is open-drain voltage, which is equal to GND (logic zero) and for high impedance the logic is one. Hence there is a need for pull-up resistors and external power supply VDD (3.3V or 5V).
Figure 1‑1 shows an example of connecting devices to the I2C bus. In the figure, we can see that there is one Master (for transferring the data) and three Slaves (to receive the data). Master specifies the command that you want to read information (Read) or send information (Write) to the Slave device. Device identification of the Slave in needed for communication which is established by using a 7-bit or 10-bit address and is set by the manufacturer. Information about the address is listed in the datasheet of the device and can be defined either in software or hardware.
Figure 1‑2 shows the communication pattern and data transmission process. Details are mentioned below.
Figure 1‑2: I2C communication pattern
Figure 1‑3 shows an example of reading the temperature measured by the humidity sensor (HIH6130). Data is of 2 bytes.
Figure 1‑3: Sample reading measured by humidity sensor
Waijung I2C Blockset includes I2C Master Setup Block which is shown in Figure 1‑4. User need to select 3 pins i.e. SDA, SCL and the frequency.
Figure 1‑4: Characteristics and user settings for I2C Master Setup Block
I2C Master Read/Write Block is shown in Figure 1‑4 have functions to receive or send data to Slave device with I2C using STM32F4DISCOVERY as Master device. User can set 7 bit Address of Slave device that want to communicate via I2C.
Figure 1‑5: Characteristics and settings for I2C Master Read/Write Blockset
Figure 2‑1: aMG Humidity/Temperature sensor
Figure 2‑1 shows the board measuring humidity / temperature. Install the sensor HIH6131-021-001 from Honeywell, which has the following features.
Alarm feature: This provides the ability to monitor whether the RH level has exceeded or fallen below predetermined and critical levels within the application. (See the work [4]).
When users want to read both the humidity and temperature, sensor must submit a Request to Address in the specified format as shown in Figure 2‑2.
Figure 2-2: Shows an I2C communication for humidity and temperature readings [2, p. 1]
After that, the Master device starts reading from the sensor and read data is of 4 bytes (32 bits), which includes the status of the sensor (2-bits), humidity (14-bits) and temperature (14-bits).
Figure 2-3: : I2C communication for humidity and temperature sensor [2, p. 2]
Figure 2-4: Sensor status
Digital Readout can be converted to units% RH and Celsius. According to the following equation:
Humidity (%RH) = 14bit_HumidityData x 100 / (2 14 -2)...........................................(1)
Temperature (◦C) = [14bit_TemperatureData x 165 / (2 14 -2)] – 40........................ (2)
Figure 2‑5 shows the aMG Sense Humidity / Temperature board with aMG F4 Connect. Furthermore connection with power supply, SCL, SDA and GND are also highlighted. The user must select the I2C module 1 and address. The active SDA pin is PB7 and for SCL is PB8.
Figure 2-5: Connections between aMG Sense Humidity / Temperature with aMG F4 Connect
Purpose
Figure 2-6: Simulink Model for humidity and temperature through I2C communication
Figure 2-6 shows the Simulink model for reading the humidity and temperature from HIH6131 sensor through an I2C communication and display the results to LCD. The description of work is as follows:
Figure 2-7: Enable subsystem block of request
The display data (that has to be converted to) relative humidity and temperature which has been mentioned in equation above is shown via LCD display.
Figure 2-8: Enable Subsystem Model for readings from sensor and operation of Binary Operation
Experimental results show the relative humidity and temperature readings from sensors HIH6131 communication through I2C and LCD display updates the display every 0.5 seconds.
Figure 2-9: Experimental results of humidity and temperature readings from sensors HIH6163
Waijung Blockset version 13.12a has a block to read data from HIH6131 sensor in Simulink library: Waijung Blockset >> Hardware Modules>> aMG Sense Temp Humid. Figure 2 10 shows an example of using HIH6131 block. User have to put I2C Master Block on main model. Data which is received from HIH6131 are relative humidity and temperature. User can immediately use them to display or record data.
Figure 2-10: Simulink Model for humidity and temperature readings using HIH6131 block
Figure 3-1: aMG Sense Pressure / Altitude board
- Pressure: 20-bit measurement (Pascals)
- Altitude: 20-bit measurement (meters)
- Temperature: 12-bit measurement (degrees Celsius). The MPL3115A2 is offered in a 5 mm x 3 mm x 1.1 mm LGA package and specified for operation from -40 °C to 85 °C.
Value of Slave address, 7 bit Address of MPL31152A, is 0x60 [5, p. 6] or ‘1100000’ when combined with Read/Write bit the binary will be ‘11000000’ or 0xC0
Flow chart of using and reading data as polling is shown in Fig [5, p. 12] . Read data as air pressure to use as Barometer [5, p. 32]
Figure 3-2: Flow chart for settings the sensor
Pressure and temperature data can be converted digitally to the air pressure in Pascal and the temperature in degrees Celsius. The next experiment describes this phenomena.
Purpose
Figure 3-3: Simulink model for reading air pressure and communicates through I2C
Figure 3-3 shows the Simulink model for the reading of the air pressure using MPL3115A2 sensor and communicates through an I2C and displays the results on a LCD screen. In this example, we will read the air pressure and the reading of the Polling which have to start from the default settings by subsystem block which is shown in Figure 3-4.
Figure 3-4: Subsystem model for the initial setup of the sensor MPL3115A2
Subsystem in Figure 3‑4 will check that MPL3115A2 has set the values as in Figure 3‑2 or not. Register 0x26 of sensor must be equal to 0x39 and register 0x13 must be equal to 0x07. If the setting is correct, the ON signal will be sent to start reading and if not correct then follow as shown in Figure 3‑5.
Figure 3-5: Subsystem Model for initial configuration MPL3115A2 Sensor with I2C Master Write
When completed, the sensor began to read the air pressure and temperature which are identified in Figure 3‑6. Address of the registers of the sensor (in the registers address 0x00) to read the air pressure and temperature which are 3-byte, 2 bytes, respectively.
Figure 3-6: Enable Subsystem Model for reading data from sensors MPL3115A2
When status of sensor has data which is not ready to be sent (DATA_VALID = 1), value of air pressure will be in digital data (20 bit unsigned). Data’s (always positive) first 18 bits will come from P_LSB and last 2 bit in position 5-4 of P_LSB showing decimal value [5, p. 23]. All data will be converted into pressure value in Pascal by Convert Subsystem Block that shown in Figure 3‑7. Figure 3‑8 shown example of Convert Subsystem Block.
Figure 3-7: Enable Subsystem Block for converting pressure units from digital form into Pascal
In order to display temperature data from MPL31152A user have to create Subsystem Model for convert read data in digital data to 12 bit data in 2’s complement. First 8 bits come from T_MSB and last 4 bits in 7-4 of T_LSB for display decimal value.
Figure 3‑8: Example to convert Subsystem Block
Figure 3‑9 shows experimental results showing the air pressure readings from sensors MPL3115A2 communication through I2C and then displayed through the LCD.
Figure 3‑9: The results of the pressure sensor readings MPL3115A2 communication through I2C
If the user wants to read the height above sea level (Altitude), this can be done by setting up a working sensor MPL3115A2 as an Altimeter Model (registers 0x26 sensor be equal 0xB9) then create Subsystem model for conversion. The height above sea level readings are in the form of digital data. Data is a 20-bit 2’s complement (positive and negative), the first 16-bit data from the P_MSB and P_CSB bit of P_LSB 7-4 showing the decimal places (resolution 0.0625 m) [5, p. 23].
In Waijung Blockset version 13.12a, block for reading data from MPL3115A2 sensor is available in the Simulink library: Waijung Blockset >> Hardware Modules >> aMG Sense Pressure. Figure 3-10 shows an example of using MPL3115A2 block. Users must place the I2C Master Block Model. Primary data from MPL3115A2 block is the air pressure. The information can then be used to display or record it immediately.
Figure 3‑10: Simulink Model for checking the air pressure using MPL3115A2 Block
In this section, an example is demonstrated for intensity of light from LDR sensor using analog signal [6]. The resistance of LDR sensor will vary in accordance with the variation in the light intensity. However LDR sensor is not suitable to measure light intensity because conversion of voltage to light intensity unit (LUX) is dependent on the electric voltage and resistance which are affected by external temperature.
Figure 4‑1: aMG Sense Light2
Figure 4‑1 shows aMG Sense Light2 board for photometric and sent over the I2C sensors from MAX44009 (Manufacturer: Maxis Integrated). This board has the following features.
User can select Slave address of MAX44009 by connecting supply voltage )VDD) or Ground (GND) at pin A0 (Pin3) of MAX44009 when connected to supply voltage (address is 0x96) or Ground (Address is 0x94) respectively.
Figure 4‑2: Map of Slave address MAX44009 [7, p. 16]
To read data from sensors, users must read from I2C by address of the Register within MAX44009. Figure 4‑3 shows that the intensity of light measured in digital format in Address 0x03 and 0x04 with an exponent of Exponential [E3-E0] and the Mantissa [M7-M0]. Light intensity in Lux can be obtained from the following equations.
Figure 4‑3: Diagram of the MAX44009 register address [7, p. 7]
Purpose
Figure 4‑4: Simulink Model for photometric readings and communication through I2C
After downloading the model into STM32F4Discovery, light intensity reading will start at the address of register of sensor we want to read. By start reading at value of sensor at register address 0x02 the readings of light intensity value (2 bytes) will be in register address 0x03 and 0x04 respectively.
Then convert data into “Lux” unit by Subsystem Model as Figure 4‑5. Since Simulink Block for power calculation cannot work with GNU compiler so user should use custom code block or MATLAB function Block. This example use MATLAB Function Block in Simulink library: Simulink >> User-Defined Functions.
Figure 4‑5: Subsystem for converting digital data into a unit Lux
Figure 4‑6 shows experimental result of the experiment in which the intensity of the light is measured using MAX44009 sensor by reading every 1 second. Reading of light intensity is increased when the light is very bright (up to 188,000 Lux when it gets direct sunlight).
Figure 4‑6: Results of photometric readings from the sensor MAX44009
In Waijung Blockset version 13.12a, reading data from MAX44009 block can be done via Simulink library >> Waijung Blockset >> Hardware Modules >> aMG Sense Light. Figure 4-7 shows an example of using the MAX44009 Block. User must place I2C Master Block Model. Users can use this module for displaying and recording the information immediately.
Figure 4‑7: Simulink Model for reading the light intensity using MAX44009 Block
Time is money. Human life is dependent on time. We set our schedule for everyday life to match with the present life demands. So we can say that human life style is associated with time. There are many units of time by volume. The smallest unit of time is second and 60 seconds makes a minute. 60 minutes makes an hour and 24 hours makes one day which defines our life routine. 30 or 31 days makes a month and 12 months constitutes a year. These all definitions are related with the rotation of the Earth around the Sun.
The SI definition of second is “the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of ground state of the Caesium 133 atom”. In embedded system, crystals are used to create a defined frequency signal with a fixed frequency. For example, in the CPU or computers and microcontrollers, timing is determined by crystal circuit which gives a very precise frequency and is less affected by outside temperature.
Time is necessary in personal computer system especially in data storage that has to keep date, month, year. Time reference can be used in small embedded system too, for the example: store data from sensors with date, month, and year, or setting a timer to on and off automatic devices.
Figure 5‑1: aMG high precision RTC
Figure 5‑1 shows the display board aMG High Precision RTC DS3231 from Maxim Integrated Raid which is a digital clock module. The module has a crystal inside having a signal frequency of 32kHz, which is used to count the seconds, minutes, hours, days, months and years of a calendar in order to adjust the date, the leap year (1 year = 366 days) till the year 2100. [8, p. 1]. All data is sent via the I2C communication module which can be connected to a battery backup to maintain the time no matter power of microcontroller goes off.
Slave device address of the IC DS3231 is 0xD0 [8, p. 17]. To read a clock and calendar, users must read that from the specified I2C address register of the DS3231 as shown in Figure 5‑2. Address of 0x00 to 0x06 is to keep the clock and the date correct. The data format is Binary-coded Decimal (BCD).
Figure 5‑2: Memory map of digital clock module [8, p. 11]
In Simulink Library >> Waijung Blockset >> Hardware Modules >> aMG High Precision RTC Block for DS3231 through I2C interface consists of the following.
After putting the battery back-up or start the DS3231 clock for the first time, the calendar data and time is will be shown as 01/01/00 00:00:00 (day / month / year. Hours: minutes: seconds), so it is necessary to set the clock. DS3231 Configure Block is Subsystem Block included in DS3231 Blockset so that the user can set the time by pressing buttons (Digital).
Figure 5‑3: DS3231 configure block
Input port of the DS3231 Configure Block has the following functionalities.
Purpose
Figure 5‑4: Simulink Model for the initial setup of the module clock DS3231
Download model on the microcontroller and setup procedure is as follows.
Purpose
When users put the battery back-up and set the digital time clock module, users can read the time and date of DS3232 Get Time and DS3232 Get Date respectively. Figure 5‑5 shows Blockset for reading the time and date of the DS3232 which communicates through I2C so the user must place the I2C Master Block.
Figure 5‑5: (a) DS3231 Get Time Block, (b) DS3231 Get Date Block
DS3231 Get Time Block display the time read from the DS3231 digital clock module and the characteristics are as follows.
DS3231 Get Date Block displays the date on the calendar to read from DS3231 digital clock module are as follows.
Figure 5‑6: Time for reading date from the module clock
Figure 5‑6 shown Simulink Model to read time and date from digital clock module by adding controlling part to ON-OFF external device by clock and change displayed date format.
After downloading the model into microcontroller, LCD shows calendar by Month. Character Subsystem Block in Figure 5‑7 will get month value and display in English format. Ex: data read from Month = 2, display will show it as Feb.
Figure 5‑7: Subsystem for displaying the month in English
Furthermore, user can apply DS3231 to use as Timer to ON/OFF external device. For example, when reading Hour, if the value is in between 12 and 13, digital output signal at PD12 will be ON so the LED1 will be on at 12:00:00 to 12:59:59 as shown in Figure 5‑8.
Figure 5‑8: Results – Reading the DS3231 clock, clock module and LED ON-OFF
Purpose
When setting the digital time clock module, users can set the time and date on DS3232 Set Time and DS3232 Set Date Block respectively. Figure 5 9 shows Blockset to set the time and date of the DS3231 and it communicates through I2C. The input for DS3232 is Slave address, hour, minute and second and for DS3231 Set Date Block the input is Slave address, Date, Month, Year.
Figure 5‑9: (a) DS3231 Set Time Block, (b) DS3231 Set Date Block
Following are the attributes of DS3231 Set Time Block. and Set Date Block.
Following are the attributes of DS3231 Set Date Block.
For this experiment users should pursue peripheral control via serial communication.
Figure 5‑10: Simulink Model for setting time and date of DS3231 via UART communication
Download Simulink model as shown in Figure 5‑10 into the microcontroller. The LCD display will show the time and date which is read from the DS3231 module. To set the clock, user must type respective commands on programs like TeraTerm or Putty terminal window like T = hours: minutes and then press Enter to Activate Subsystem in Figure 5‑11. An acknowledgement message of Ok will be sent and the clock settings will be complete and the LCD display will be showing the updated time.
Figure 5‑11: Subsystem model for clock setting
To set the calendar, users need to type the command D = Date – Month – Year, and then press Enter to Activate Subsystem as in Figure 5‑12 which is a Subsystem Model for the calendar. Ok acknowledgment signal will be sent and setting of calendar will be complete. LCD will now be showing the data.
Figure 5‑12: Subsystem model for the calendar
Figure 5‑13 shows the equipment used in this study. Computer is connected to the aMG USB Converter-N Adapter. If not battery backed clock module is available then the LCD display will show the date as 1 January 2000 and start the clock at 0:00.
Figure 5‑13: Experiment for clock setting via computer
Figure 5‑14 shows the clock setting. After typing the command in Teraterm program, the program will communicate with the computer via serial port. Users can set the clock or calendar. When the clock is set, seconds start counting from 0 every time.
Figure 5‑14: Results of clock setting through UART communication
Purpose
Digital clock DS3231 module have a temperature sensor installed inside to reduce the error caused by temperature to external crystal circuit. As a result, the clock signal is the most accurate for temperature measurement. Figure 5‑15 shows DS3231 using DS3231Temperature Block, located in the Simulink Library >> Waijung Blockset >> Hardware Modules >> aMG High Precision RTC.
Figure 5‑15: Simulink model for the temperature reading from DS3231 and it communicates through I2C
Download model into the microcontroller and LCD display will show the temperature measurement. The precision of the reading is +/- 3 ° C [8, p. 1].
Figure 5‑16: Results from measuring the temperature using DS3231 (communicates through I2C)
Objective:
This example introduces the use of sensor for measuring humidity, temperature air pressure and light intensity at the same time by connecting SCL and SDA of the aMG board (Sense Humidity/Temperature, aMG Sense Pressure/Altitude and aMG Sense Light)2 in Bus is shown as Figure 6‑1.
Figure 6‑1: Connection kit for detection of humidity, temperature, air pressure and light intensity
Figure 6‑2 shows a Simulink model for measuring temperature, humidity, air pressure and light intensity. Communication is using I2C and LCD screen displays time and date. Digital clock DS3231 modules are connected on the aMG F4 Connect board. The time and date information will be updated every 0.5 seconds.
If one sensor is pulled off, LCD still display latest read value of that sensor and model still reads value from sensor.
Figure 6‑2: Simulink Model for measuring temperature, humidity, air pressure and light intensity
Figure 6‑3 shows the experimental measurements from sensors connected to the system bus. As discussed in Figure 6‑1, when connecting the power supply and 3.3V to SCL SDA GND pin of aMG F4 Connect to the sensor, the data (temperature, humidity, air pressure and light intensity) will be displayed on the LCD display and it will be updated every 0.5 seconds.
When installing the digital clock module (DS3231) that was to set clock value on aMGF4 Connect, first line of LCD will show present date and time.
Figure 6‑3: Results of sensor measurements and communication via I2C
References
download all demo files: Flash.7z
In embedded systems, it is very important to have a memory which can store the information. Programs (set of instructions) are used to make an embedded system behave in such a manner according to the user requirements. Our programs are written in C or Waijung Blockset which compiles the set of instructions. Microcontroller uses flash memory which can be erased and re-programmed. Some space of the memory can be re-programmed and some space of the memory is fixed (i.e. cannot be re-programmed) and it depends on the manufacturer of the microcontroller how they manages the memory allocations.
STM32F4DISCOVERY board have a STM32F407VGT6 microcontroller which has a capacity of 1 MByte flash memory. The flash memory of the microcontroller has been divided into the sectors and each sector have its respective starting and ending addresses. Some sectors are of small size and some are of large size. Allocation of flash memory space is shown in Figure 1‑1.
Figure 1-1: Allocation of flash memory space within the STM32F407 [1, p. 54]
The allocation of internal flash memory of STM32F407 is as follows.
The Waijung library has a blockset for using Internal Flash Memory Block having an option of erasing read and write data. The use is limited from sector 5 to 11.
Simulink library >> Waijung Blockset >> STM32F4 target >> On Peripheral Chip >> FLASH contains a blockset for managing the data in the flash memory. Flash Erase block parameters are shown in Figure 1‑2 which is used for deleting the data from the sectors. It takes about 1 to 2 seconds to erase the data from 128 KB memory [2, p. 106].
Figure 1-2: Features of Flash Erase Block
Block parameters of Flash Read are shown in Figure 1‑3. It is used to read the data from specified memory. For example, if used wants to read the address: 0x080E0500, following are the steps.
Thus Offset = 0x80E0500 – 0x80E0000
= 0x0000500 = 20480 (in decimal)
Figure 1-3: Characteristics of Flash Read Block
Flash Write block is shown in Figure 1-4. It is used for write data to the memory offset of specific sector id. The procedure for assigning the address and specifying the offset address is same as that of Flash Read Block as described above.
Figure 1-4: Characteristics of Flash Back Block
http://www.st.com/web/catalog/tools/FM146/CL1984/SC724/SS1677/PF251168.
Objective
Figure 2-1: Simulink model for writing and erasing the data from flash memory
This experiment is conducted to write or erase flash memory address at 0x080E0500 using Simulink model as shown in Figure 1‑1 which consists of a three major blocks.
Figure 2-2: Within Flash Erase Subsystem model
Figure 2-3: Within FlashWritingSeq Subsystem model
While writing in the flash memory, it is good to erase the already existing information on that sector which can be done by using Flash Erase Block which will delete the information of the entire sector.
After the Simulink model is downloaded into STM32F4DISCOVERY board, LED1 which is connected with PD12 will blink. To observe the changes in the flash memory, this experiment uses STM32 ST-Utility program and have the following main steps.
Figure 2-4: STM32 ST-Link Utility window after connecting with STM32F4DISCOVERY
Figure 2-5: Core panel window
Data in memory will be shown in hexadecimal format in a table form. Rows and columns show the position of address. User can adjust the memory display as follows.
Figure 2-6: Window displaying data in the memory (Data Width 32 bits or 4 Bytes)
When user set the Data Width = 8 bits on the memory display then the display will change as shown in Figure 2‑7. Now the size of address is 8 bits value (00 to FF).
Figure 2-7: Window displaying data in memory (Data Width 8 bits or 1 Byte)
Figure 2-8: Windows displaying the data in memory after writing
Figure 2-9: Window displaying the data in memory after deletion
Objective
Figure 2-10: Simulink Model for reading data from Flash Memory and displayed through the LCD
From the example, in this experiment, users can observe data by STM32 ST-Utility connected to a computer with USB cable. Furthermore, user can observe data that has been record via LCD.
This experiment uses the model as shown in Figure 2‑10 for reading data from the flash memory and display it on the LCD which is an additional part when compared with the model shown in Figure 2‑1. Switch SW3 is used for updating the value read from flash memory and then display it on LCD. Figure 2‑11 shows internal subsystem model for reading data at address: 0x080E0500.
Figure 2-11: FlashRead Subsystem Model for reading data from Flash Memory
If user wants to write multiple data sets, user can edit Block in FlashWriteSeq Subsystem as in Figure 2‑13. In this example, 3 sets of data are written which have different type of variables (uint8, uint32 and single). User can add Flash Write Block and set any address within range of 4 Bytes
Figure 2-12: Values read from Flash Memory through the LCD display
If user wants to write multiple data sets, user can edit Block in FlashWriteSeq Subsystem as in Figure 2‑13. In this example, 3 sets of data are written which have different type of variables (uint8, uint32 and single). User can add Flash Write Block and set any address within range of 4 Bytes.
Figure 2-13: Subsystem model for writing or recording in multiple Flash Memory
So in the example, if the value read from the DIP switch is set to 12. Information address: 0x080E504 is equal to 12000 and address: 0x080E508 is equal to 1481.40 so users can check in flash memory window which displays the data in memory as shown in Figure 2‑14.
Figure 2-14: Window displaying data in the memory
Users can learn how to convert a decimal number to binary floating-point arithmetic from the following link http://www.h-schmidt.net/FloatConverter/IEEE754.html. This is known as IEEE-754 standard.
Figure 2‑15 is an example of subsystem for reading 3 data sets of different type of variables (uint8, uint32 and single). User can add the Flash Read Block and set address that want to read.
Figure 2-15: Subsystem for reading data of multiple types
Download the model and information stored in DIP switch, SW1 switch and SW2 switch will be displayed on the LCD display which is shown in Figure 2‑16.
Figure 2-16: Reading value from multiple data sets of flash memory and display it on the LCD
Although user can turn ON-OFF the electric power or download model into STM32F4DISCOVERY again, data in sector 5 – sector 11 will still remain unchanged. So using internal flash memory is suitable for working with data which is not changed so often, for example security or setup section.
download all demo files: SPI.7z
Serial Peripheral Interface or SPI is another form of Serial Synchronous Communication. In this type of communication one device works as Master while another acts as a Salve. Master device initiates the data frame and there can be multiple slave devices. SPI works in full duplex mode. Signals between Master and Slave can be sent simultaneously. One of the biggest advantage of SPI protocol is that the complete protocol has flexibility for the bits transfer and not limited to 8-bit words. There can be arbitrary choice of message size content and purpose.
Here are few examples for the devices which uses SPI communication
Figure 1‑1 shows the connection between SPI Master and Slave. The link have four lines/wires
Master device’s function is to control all communications with clock signal and signal line SS. The Master will decide whether to receive or send data into slave device signal line SS (Slave Select) in case of having more than one slave by make signal level of that SS LOW. If we want to connect to particular SS, just set the signal level of that SS to LOW as shown in Figure 1‑2.
Figure 1-2: SPI communication between Master and Slave
When comparing the SPI communication with I2C communication, the former one has higher throughput and is ideal for low speed data communications such as EEPROM memory module or digital clock.
SPI communication has an advantage of full duplex communication that is able to transmit and receive simultaneously for particular cable. Typically SPI has lower power requirements than I2C due to simple hardware interface. Slaves use the master’s clock and do not require precision oscillators. SPI is not limited to any maximum clock speed, enabling potentially high throughput.
Waijung Blockset consists of SPI Master Setup Block as shown in Figure 1‑3. To set any Register values related to SPI communications i.e. select SPI module in STM32F4DISCOVERY up to three sets, select pin MOSI/MISO/SS and set frequency of clock signal in SCLK.
Figure 1-3: Characteristics of settings of SPI Master Setup Block
SPI communication has no certain pattern, in order to set communication pattern of Master device to match with Slave we have to do the following things:
Figure 1-4: Data is received or sent when CPOL = 0 and CPHA = 0 0 [1, p. 800]
When the clock polarity is LOW and clock phase 2nd edge (CPOL_Low/CPHA_2Edge), the system will start reading first bit when found second edge of signal (negative edge) as shown in Figure 1‑5.
Figure 1-5: Data receiving and sending when CPOL = 0 and CPHA = 1 [1, p. 800]
When the clock polarity is HIGH and clock phase 1st edge (CPOL_High/CPHA_1Edge) is at the initial state (clock signal will be in HIGH state), the system will start reading first bit when found first edge of signal (negative edge) as shown in Figure 1‑6
Figure 1-6: Data receiving and sending when CPOL = 1 and CPHA = 0 [1, p. 800]
When the clock polarity is HIGH and Clock phase 2st edge (CPOL_High/CPHA_2Edge), the system will start reading first bit when found second edge of signal (positive edge) as Figure 1‑7
Figure 1-7: Data receiving and sending when CPOL = 1 and CPHA = 1 0 [1, p. 800]
SPI Master Read/Write Block as shown in Figure 1‑8 receives or sends data into slave device by SPI. STM32F4DISCOVERY is used as Master device and user can set number of byte which need to be sent.
Figure 1-8: Properties and setting the values of SPI Master Read/Write Block
This section describes how to use SPI communication to control devices. This example given below uses IC LTC1661 (from Linear Technology). Signal converter module is used to convert 10 bits to 2 analog channels. Although STM32F4DISCOVERY has 2 DAC channels, users can use this device if they want to add more analog voltage supply channel.
Figure 2-1: IC PINs of LTC1661 [2]
Figure 2‑2 shows the data of LTC1661 through SPI to adjust the voltage. When looking at clock signal pattern, in Idle state, the signal is LOW and reads data bit on MOSI when the positive edge is found (1st edge capture). One data set has 16 bits containing a digital value. 10 bits are needed to convert the voltage value and 4 bits control code for controlling IC LTC1661 and last two bits are don’t care bits as shown in Figure 2‑3. Maximum frequency of clock signal that IC LTC1661 can work properly is 16.7 MHz [2, p. 3].
Figure 2-2: SPI Communication of IC LTC1661 [2, p. 9]
Figure 2-3: Description table of Control Code of IC LTC1661 [2, p. 9]
Figure 2-4: Installation of signal generator with IC LTC1661
Figure 2‑4 shows connection between STM32F4DISCOVERY and IC LTC1661 on the aMG F4 Connect board having port to connect SPI device by setting PA15 pin as Slave Select (NSS), PB3 pin as SCLK, PB4 pin as MISO and PB5 pin as MOSI. IC LTC1661 receives data from Master device only. Users just have to connect transmission line for MOSI data.
Table 2-1: Connection between STM32F4DISCOVERY and IC LTC1661
Objective:
Figure 2-5: Simulink Model to generate one channel analog signal with ICLTC1661
Figure 2‑5 shows Simulink model for creating one channel analog signal with IC LTC1661 through SPI communication. After downloading the model into STM32F4DISCOVERY, the value of Control Code = 1001 and value from Counter Limited Block will be exported and Counter Limited Block will start counting from 0 to 1023 every 0.1 ms to Slave device for DAC. After 0.1 second, the value of Counter will start from 0 again (So the signal frequency is 10 Hz). Figure 2‑6 shows the signal measured from pin 8 (Vout A) of IC LTC1661 using Oscilloscope.
The measurements from Figure 2‑6 shows the signal frequency of 9.766 Hz or has signal period = 0.102 seconds and maximum signal value is around 3.04 V.
Figure 2-6: Experiment result of analog signal generation with IC LTC1661
Figure 2‑7 shows a Simulink Model for constructing two channels of analog signal. Control Code = 10 is used for sending DAC to B channel, and Pulse Generator Block is used for selecting data to send to SPI.
When the value of Pulse Generator Block is 0 and the value of Control Code = 1010, a constant value of 256 will be sent thus VoutB = (259 / 1023) x 3 = 0.826V (can measure by Digital Multimeter). When Pulse Generator Block = 1 and value of Control Code = 1010 and value of Counter will be sent alternatively every 0.05 ms.
Figure 2-7: Simulink Model to generate two channels analog signal with multiplexer technique
Nowadays, the use of linear accelerometer has been increased tremendously in smart control systems such as screen adjustment of LCD in smartphones and notebooks, vibration detector, burglar alarm and subsystem of navigational system in unmanned aerial vehicle (UAV).
When we are on earth surface and drop an object to the earth, that object will fall into the ground with constant acceleration known gravitational acceleration (g). The value of g is known to be 9.8 m/s. If we measure an object with 3g acceleration, it means it is travelling with the speed three times than the gravitational acceleration.
This experiment uses STM32F4DISCOVERY as shown in Figure 3‑1 installed with accelerometer LIS302DL developed by STMicroelectronics. Properties of LIS302DL are:
Figure 3-1: Device installation for reading data from LIS302DL sensor through SPI communication
In order to read data from SPI, user need to read the communication format of LIS302DL from Datasheet [3]. Data reading formats of LIS302DL has two ways to read, one byte (8 bits data) and multiple bytes per time. Number of bytes depends on command. Figure 3‑2 shows the data format of LIS302DL. Master device send the command and address of internal register of LIS302DL.
Figure 3-2: Data reading form of LIS302DL through SPI 1 byte per time [3, p. 22]
Multiple bytes reading can be done by setting M/S = 1 and define the initial start address. Data from LIS302DL will be sent to Master device on the tempo of SCLK signal. When 8 bits are sent already, LIS302DL will send data from next address until the Master device stop data reception.
Figure 3-3: Data reading form of LIS302DL through SPI, multiple bytes (in this example 2 bytes)
Writing data into LIS302DL has two ways too. In Figure 3‑4 and Figure 3‑5 shows data writing to LIS302DL one byte and multiple bytes per time respectively. Master device send writing command and address of internal register of LIS302DL then data is sent to set value in that register.
Figure 3-4: Data writing form of LIS302DL through SPI one byte per time [3, p. 22]
Figure 3-5: Data writing form of LIS302DL through SPI multiple bytes [3, p. 23]
Figure 3‑6 shows the address of internal register of LIS302DL. Each register has different functions, such as controlling the functionality of the sensor, store variable values and store the measured linear acceleration value etc.
Figure 3 6: Address of internal register of LIS302DL [3, p. 24]
Simulink model for reading acceleration values in three axis of LIS302DL sensor is shown in Figure 3‑7. The model in figure below has three main functions:
Figure 3-7: Simulink Model for reading data from LIS302DL sensor through SPI communication
After downloading model into STM32F4DISCOVERY, the program will read initial state of LIS302DL by subsystem as in Figure 3 8. That is the one byte data reading as SPI from CTRL_REG Register at (Address 0x20). If the read value is not equal to 0xC7, the data is written as SPI at CTRL_REG Register.
Figure 3-8: Subsystem model for setting up initial value of LIS302DL
Then LIS302DL Read Subsystem starts to read the acceleration values of the three axis. All data are in Out_X, Out_Y and Out_Z Register (Address 0x29, 0x2A and 0x2D) respectively. Figure 3‑9 shows data reading as SPI 6 bytes and set Out_X to be starting address.
Figure 3-9: Subsystem Model for reading acceleration value of three axes from LIS302DL
The read value is int8 type, signed integer 8 bit (value -127 to 127) and display it via UART communication every 0.02 seconds or 50 Hz. Figure 3‑8 shows settings of Full Scale selection (FS) = 0. That’s means measuring linear acceleration in interval ±2g thus linear acceleration (unit: g m/s2) can be calculated from equation:Then LIS302DL Read Subsystem starts to read the acceleration values of the three axis. All data are in Out_X, Out_Y and Out_Z Register (Address 0x29, 0x2A and 0x2D) respectively. Figure 3‑9 shows data reading as SPI 6 bytes and set Out_X to be starting address.
Acceleration = 2 x measured value/ 127
When the Z-Axis of sensor is in the line of the gravity, the measured acceleration is 1g or the value = 64
Figure 3‑10 shows linear acceleration via TeraTerm program on STM32F4DISCOVERY. Acceleration value in Z-axis will be maximum because of gravitational acceleration and the value in X-Y axis will be minimum because they are parallel with earth surface.
Figure 3-10: Experimental results of linear acceleration data reading
When an object is crashed, the acceleration will be changed in short time and we can use the sensor to detect it and bring that value to alarm or control any devices for further processing. For the examples, burglar alarm, vibration detector, safety airbag, etc.
Figure 3‑11 shows Simulink model to display the value of linear acceleration in real time. This model is working on computer (Don’t need to download into STM32F4DISCOVERY) when connected STM32F4DISCOVERY via USB and press Run icon. This program will read linear acceleration value from STM32F4DISCOVERY through USB cable.
Figure 3‑11: Simulink model to display result of linear acceleration in real time
Note: You should close all serial communication programs before running this model.
Figure 3-12: Devices preparation for experimenting with linear acceleration in real time
After double clicking the Scope Block, graph of linear acceleration in 3 axis will appear in real time, it mean the pattern of graph will change if STM32F4DISCOVERY changes its position as in Figure 3‑13.
Figure 3‑13: Graph of real time linear acceleration measured by LIS302DL
download all demo files: UART.7z
Modern embedded systems are often based on microcontroller which can be connected to various external devices which enables the embedded system to send and receive information to external devices.
Figure 1‑1: Parallel data transmission between FiO2 and aMG Camera INF
Communication between microcontroller and external device can be classified into two types:
In STM32F4DISCOVERY, there are many types of communication module UART, I2C, SPI, USB, CAN bus and Ethernet etc. In this section, UART module will be discussed.
UART stands for Universal Asynchronous Receiver Transmitter that will connect and communicate with serial devices such as computers, RFID, GPS, GSM module, Wi-Fi module etc.
The advantages of using asynchronous communication is availability of full duplex communication i.e. it can send and receive data between the transmitter and receiver simultaneously and do not require clock synchronization for data transfer. The universal designation indicates that the data format and transmission speeds are configurable.
Figure 1‑2: Communication model for Universal Asynchronous Receiver Transmitter [1]
Figure 1‑2 shows the format of UART communication with users to define these properties Following are some typical configurations;
In addition, users should consult the voltage level of the signal required by UART communication.
Figure 1‑3 shows the connection between the serial communication Transmit Data (Tx) pin of transmitter with Received Data (Rx) pins of the receiver to send and receive the data. Transmitter and receiver should have a common ground. If the devices are connected with different voltage levels then additional electronic components like MAX232 [2] should be added in path to adjust the voltage level.
Figure 1‑3: UART connection
The blockset responsible for transfer of data via UART protocol in STM32F4DISCOVERY can be accessed from Simulink library >> Waijung Blockset >> STM32F4 Target >> On Peripheral Chip >> UART consisting of UART setup, UART Tx and UART Rx block
If users want to use UART STM32F4DISCOVERY, then users need to have UART Setup Block in Simulink model.
The UART Setup Block features are shown in Figure 1‑4. In the settings, serial communication port UART module 3 is used and PD8 and PD9 are used for Tx and Rx respectively. Baud rate is set to be 115200 with no parity bit, 1 stop bit.
Figure 1‑4: UART setup configuration
In this section, introduction to aMG USB Converter-N-Adapter is given which has FT2232H high speed USB 2.0 (480 Mbps), a UART/FIFO two channels [3]. Such type of hardware is ideal to be used for Hardware In Loop (HIL) simulation.
Figure 2‑1: Characteristics of aMG USB Converter-N-Adapter [3]
Figure 2‑2: STM32F4DISCOVERY and PC connection
When aMG F4 Connect is connected with the power supply and aMG USB Converter-N Adapter with the PC for the first time, the user must make sure to follow the below mentioned procedure.
Go to Start Menu, right click on Computer icon and selection the properties. A new window will appear as shown in Figure 2‑3.
Figure 2‑3: Pop up window
Go to device manager, expand the Ports (Com & LPT) which is managing the computer’s parallel ports and serial communication which is shown in Figure 2‑4.
Figure 2‑4: Device manager window to confirm port number
In addition to the above check of port number, the user need to set the Com Port Latency Time to higher speed which will help in improvement of data transmission speed which is essential in Hard in Loop Latency Timer setting. This can be done by following way.
Figure 2‑5: Advanced settings for Com Port connected with aMG USB Converter-N Adapter
Figure 2‑6: Changing the Latency Timer for Com Port
After reviewing the Com Port number and Latency Timer, next is to set the Com Port on the Host Serial Blockset (when using Hard In the Loop Simulation) or serial communications ports. In the next section, we will introduce Freeware programs to communicate through the serial port.
Tera Term is a freeware program which can be used for serial communication. The program can be downloaded from http://www.ayera.com/teraterm/. This program works only with Microsoft Windows operating system. Users can configure the communication ports and the procedure is as follows:
Figure 2‑7: Selecting communication port in Tera Term
Figure 2‑8: Setting terminal window in Tera Term program
Figure 2‑9: Serial port settings
PuTTY is a client program for the SSH, Telnet and Rlogin network protocols. Commands from the clients can be sent to the server through internet via serial communication port. PuTTY can work on Windows and Linux platforms and can be downloaded from http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Following steps are helpful in while using the serial port with putty
Figure 2‑10: Putty configuration
Figure 2‑11: Terminal settings in Putty
Serial port settings for Putty are shown in Figure 2‑12. The baud rate is set to be 115200 bps with no parity bit and one stop bit.
Figure 2‑12: Serial port settings for Putty
UART Tx Block is used to send data out of the microcontroller to the external devices via Tx pins and provides a convenient way for the transfer of data. There are three Packet Modes available and user can choose any one of them. These modes are ASCII Mode, Binary Mode and String Buffer Mode.
Figure 2‑13: UART Tx Block settings
Purpose
Figure 2‑14: Simulink model for UART Tx
When the program is downloaded in STM32F4DISCOVERY, the text included in ASCII Format Dialog and End of Packet i.e. ‘Greeting from Waijung \n \r \ n’ will appear in Tera Term window and the same message will repeat after every 1 second (sampling time). This is shown in Figure 2‑15.
Figure 2‑15: Tera Term display message received via UART communication port
Question : What should be done if user want to set UART Tx Block messages immediately after newline?
Answer : “\n” is the newline. The example shown above ASCII Format is ‘Greeting from Waijung\n’ and End of Packet is CRLF (0x0D 0x0A – “\r\n”).
Figure 2‑16: Simulink model for sending messages in Packet mode
Simulink Model in Figure 2‑16 is an example of the Enable Subsystem for sending messages using Packet Mode or to read the digital signal. Dip-Switch is an optional mode of operation and is functionality is as follows.
When the program is running, the terminal window will display “Greeting from Waijung” every 5 seconds.
Figure 2-17: Subsystem Block for sending messages using the Packet Mode and String Buffer
When DIP-SW1 is set to OFF and DIP-SW2 is ON signal from the switch activates Sub System “SendMessage Bin”, which is an example of using the UART TX Binary Packet Mode. Figure 2‑18 contains the Sub System.
Figure 2-18: Subsystem Block for sending messages using the Binary Packet Mode
The Terminal window displays a character-only (ASCII Printable Character) from The ASCII Code Table [3]. In Figure 2‑19 hexadecimal code 0x00 to 0x1F which are used as an example. ASCII Control Character 0x0A is for the new line. ASCII Printable Character starts from 0x20.
When the program is running in the TeraTerm window, characters will be displayed after every 1 second as shown in the table without newline (because there is no “\ n” or 0x0A) but begins to the left every time.
Figure 2-19: ASCII table [3]
Figure 2-20: Subsystem Block for sending messages using the ASCII Packet Mode
Figure 2‑21 shows the Enable Sub System Block. Users can configure the UART Tx Block Packet Mode and sampling time.
Figure 2-21: Terminal displays messages received via the UART communication mode
UART Rx Block is used to receive data from external devices through the Rx pins. ASCII mode is selected for the Packet mode however user can choose from the three modes available.
Figure 2-22: Settings while using UART RX Block in ASCII Mode
Purpose
Figure 2-23: Simulink model for data transmission between UART Rx Blocking and computer
Figure 2-24: Simulink model for data transmission between UART Rx Non-Blocking and computer
Figure 2‑23 and Figure 2‑24 show Simulink model for the experiment for the transfer of data from computer in Blocking and Non-blocking mode respectively. The Simulink model need to be downloaded into STM32F4DISCOVERY. User can open Tera Term window and type the text “Hello Waijung” on the Terminal window. This message will appear on the LED attached with STM32F4DISCOVERY via USB when Enter key is pressed. This is shown in Figure 2‑25.
Figure 2 25: Receiving messages from the computer
When user presses Enter to specify that the message is finished, 0x0d will appear on the display but it will not appear on the LCD display of the microcontroller.
In this example, users can observe the different behavior of UART_RX Block with Blocking and Non-Blocking. UART_RX block with blocking wait for completion of the running command before running another therefore LED2 is not flashing.
For the model in Figure 2‑24, when the user selects a UART_Rx Block with Non-Blocking, the ready signal will indicate that the message has been complete. It means that the model can accept other commands while the text is still not complete without blocking the incoming messages (note that LED2 light is flashing).
Purpose
Figure 2-26: Simulink model for Peripheral control via Serial Communication
Notice that users can use the same UART Rx Module with multiple blocks but within the same Packet Mode
Download Simulink model on STM32F4DISCOVERy and connect with Tera Term. Users can type the following command.
When send command LED1=1, press Enter UART Rx Block check the received message is “LED1=%u\r” which Activate Subsystem Block then the value %u will be sent to Subsystem Block as shown in Figure 2‑27. Inside of the system containing Digital Output Block to control ON/OFF for LED1 that is connected to PD12 pin. LED will be ON if the read value is not equal to zero, so set LED1=0 then Enter, the LED1 will off and UART Tx Block send response “>>OK” to user.
Figure 2-27: Subsystem block for light controlled LED
When printing ADC% u? Press Enter UART Rx1 Block, check the messages received is “ADC% u \ r” to Activate Subsystem1 Block then it will display the voltage reading.
Figure 2-28: Subsystem block for displaying voltage reading at pin PA5
When command Input is given followed by a number and then Enter , UART Rx2 Block verify received message “Input%f\r” to Activate Subsystem2 Block and then the read value (%f) will be sent to Subsystem Block as in Figure 2‑29 then prompt the text Your Input is: and the input number.
Figure 2 29: Subsystem block for displaying input number
Figure 2‑30 the message shown on terminal screen of program TerTerm is “>>OK” after ON-OFF the LED. Show value of voltage that read from PA5 and the received number in floating type.
Figure 2‑30: Result of peripheral control by computer
Serial communication between the microcontrollers can happen directly. Therefore, users must make sure that the voltage levels between sender and receiver (in this case both are microcontrollers) are the same. This example use 2 set of microcontroller board. The first board is STM32F4DISCOVERY and the second board is FiO2 that uses microcontroller model STM32F417IG installed on board aMG F4 Connect. Both boards have voltage in serial cable approximately 3.3V.
Objective:
To make users understand serial communication between microcontroller
Figure 3‑1: Simulink model for message blocking for board 1
After downloading the Simulink model into STM32F4DISCOVERY, the numbers 0 and 1 will be sent alternatively in Packet Binary by UART Module 1 via PB6 pin. And message ‘Value=%u\n’ will be sent by UART Module 6 via PC6 pin every 0.25 seconds.
Second board will be receiver. User must download model in Figure 3‑2 into FiO2 that have two blocks of UART RX Block. The first block will receive binary data and the second block will receive Ascii data. Blocks will receive data every 0.01 second. In order to make received data correct, the receiver should have double frequency rate to transmitter.
The received data from UART will use to control ON/OFF LED1 and LED2 on aMG F4 Connect. Both LEDs will blink every 0.25 second.
Figure 3‑2: Simulink model for text blocking on board 2
User can freely choose UART module for send and receive data by selecting module in UART Setup Block then connect Tx-Rx that matched to selected module. Figure 3‑3 shows the serial cable connections between microcontrollers. Both boards use UART Module 1 and 6.
Figure 3‑3: Communication between the microcontrollers (blocking)
Objective:
Figure 3‑4: Simulink Model for send data in Non-Blocking type in Board 1
Simulink model shown in Figure 3‑4 have 3 blocks of Non-Blocking UART TX. Each block will send different Ascii data and different frequency. After downloading model into STM32F4DISCOVERY, the first board will send “LED1=%u\n” every 0.125 second. UART Tx2 Block will send “LED2=%u\n” every 0.25 second and UART TX3 Block will send “LED3=%u\n” every 0.5 second via only PB6 pin.
Second board will be a receiver. User must download model in Figure 3‑5 into FiO2 that have 3 blocks of Non-Blocking UART RX Block. Each block will read Ascii data in every 0.001 second. When received the messages value, that value will be used to control ON/OFF LED within Enable Subsystem Block. In order to make the received data correct, the receiver should have double frequency rate to transmitter, same as in Blocking type.
Figure 3‑5: Simulink Model for receive data in Non-Blocking type in Board 2
Figure 3‑6 shows serial connection between microcontroller using UART module 1 for board 1 and board 2.
Figure 3‑6: Communication between microcontrollers (non-blocking)
API สำหรับแปลง HTML เป็น PDF
AmgCnt.Python.htmlToPdf(DataObject, Callback)
amgApi.coreLib.python.htmlToPdf(Object, Callback)
1. DataObject เป็น Object ของ HTML และ Options ต่างๆ
2. Callback เป็นฟังก์ชันสำหรับรอรับ object ผลลัพธ์การแปลง html เป็น pdf
ตัวอย่างการใช้งาน
AmgCnt.Python.htmlToPdf({
html: `
<div style="text-align: center;">Hi PDF</div>
`,
options: {
'css': ``,
'orientation': 'p',
'header-font-name': 'TH-SARABUN-PSK',
'margin-top': 10,
'margin-right': 8,
'margin-bottom': 10,
'margin-left': 8,
'footer-center': 'หน้า [page] ของ [toPage] หน้า',
'footer-font-size': 9,
'footer-spacing': 2,
},
dwn_file: 'file_name.pdf'
}, function(res) {
console.log(res);
})
DataObject จะมีโครงสร้างดังต่อไปนี้
html เป็นเนื้อหาที่จัดอยู่ในรูปแบบ html
options เป็น option object ที่กำหนดการแสดงผล HTML
dwn_file เป็นชื่อไฟล์ที่จะทำการตั้งให้ pdf (ต้องตามด้วย .pdf)
var DataObject = {
html: String,
options: OptionObject,
dwn_file: String
}
| ชื่อ option | ประเภทตัวแปร | คำอธิบาย | ค่าเริ่มต้น | หมายเหตุ |
| css | string | css style ที่เสริมเข้าไปเพื่อควบคุมรูปแบบของข้อมูลก่อนการปริ้น | -ใช้ word-wrap แทน break-word -ไม่รองรับ CSS3 |
|
| page-size | string | ขนาดหน้ากระดาษ A3 A4 A5 Letter |
A4 | -ขึ้นต้นด้วยตัวใหญ่ |
| orientation | string | การวางแนวของไฟล์ PDF p คือแนวตั้ง l คือแนวนอน |
p | |
| grayscale | - | ปรับ pdf ให้ออกมาเป็นขาวดำ | -ไม่ใส่จะปริ้น pdf แบบมีสี | |
| footer-left | string | ปริ้นช่วงซ้ายล่างของกระดาษทุกหน้า | -ห้ามใช้ ' ในข้อความ [page] จะถูกแทนที่ด้วยเลขหน้าปัจจุบัน [toPage] จะถูกแทนที่ด้วยเลขหน้าทั้งหมด |
|
| footer-center | string | ปริ้นช่วงกลางล่างของกระดาษทุกหน้า | ข้อจำกัดเดียวกับ footer-left | |
| footer-right | string | ปริ้นช่วงขวาล่างของกระดาษทุกหน้า | ข้อจำกัดเดียวกับ footer-left | |
| footer-font-size | number | ขนาดของตัวหนังสือช่วงล่างของกระดาษ | ||
| footer-spacing | number | ขนาดของช่องว่างระหว่างเนื้อหาและตัวหนังสือช่วงล่างของกระดาษ ในหน่วย mm | ||
| footer-line | - | เพิ่มเส้นแนวนอนระหว่างเนื้อหาและตัวหนังสือช่วงล่างของกระดาษ | -ไม่ใส่จะไม่ปริ้นเส้นลงใน pdf | |
| header-left | string | ปริ้นช่วงซ้ายล่างของกระดาษทุกหน้า | -ห้ามใช้ ' ในข้อความ [page] จะถูกแทนที่ด้วยเลขหน้าปัจจุบัน [toPage] จะถูกแทนที่ด้วยเลขหน้าทั้งหมด |
|
| header-center | string | ปริ้นช่วงกลางบนของกระดาษทุกหน้า | ข้อจำกัดเดียวกับ header-left | |
| header-right | string | ปริ้นช่วงขวาบนของกระดาษทุกหน้า | ข้อจำกัดเดียวกับ header-left | |
| header-font-size | number, pixel | ขนาดของตัวหนังสือช่วงบนของกระดาษ | ||
| header-spacing | number, millimeter | ขนาดของช่องว่างระหว่างเนื้อหาและตัวหนังสือช่วงบนของกระดาษ ในหน่วย mm | ||
| header-line | - | เพิ่มเส้นแนวนอนระหว่างเนื้อหาและตัวหนังสือช่วงบนของกระดาษ | -ไม่ใส่จะไม่ปริ้นเส้นลงใน pdf | |
| no-images | ไม่ปริ้นรูปใดๆลงใน pdf | -ไม่ใส่จะไม่ปริ้นรูปลงใน pdf | ||
| margin-top | number, millimeter | ระยะขอบกระดาษกับเนื้อหาด้านบน | -อาจจะมีผลทำให้หัวกระดาษ ไม่ถูกพิมพ์ ให้ทำการปรับจูนค่าร่วมกับ option header-spacing | |
| margin-right | number, millimeter | ระยะขอบกระดาษกับเนื้อหาด้านขวา | 10 | |
| margin-bottom | number, millimeter | ระยะขอบกระดาษกับเนื้อหาด้านล่าง | 10 | -อาจจะมีผลทำให้หัวกระดาษ ไม่ถูกพิมพ์ ให้ทำการปรับจูนค่าร่วมกับ option footer-spacing |
| margin-left | number, millimeter | ระยะขอบกระดาษกับเนื้อหาด้านซ้าย |
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| HTTP Method | GET--POST | Specify the request type |
| Response buffer size | 32--64--128--256--512--1024--2048--4096 | Select the response buffer size |
| Enable semaphore control for HTTP block | Check--Uncheck | Having multiple HTTP blocks in the same model file can cause errors during run time. In such case this parameter should be enabled. |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time for the block |
This block can be used to GET or POST HTTP requests.
Previous : WIFI Block
Next : Wireless Communication Block (HIL)
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Name of the handler | Specify the name for the current handler. It should not be repeated. | |
| URI | Specify the uri for the handler. In case the enable waildcard for this handler is enabled specify the base uri here. | |
| Enable wildcard for this handler | Check--Uncheck | Enable or disable the wildcard for this current handler. |
| Number of requests | 1 to 12 | Number of requests handle using the current handler. This will be always 1 when the wildcard is false in HTTP Server Setup block. |
| If request is | Specify the request to be handle (uri) | |
| Compare the whole request | Check--Uncheck | Compare the request uri with the specified partially or fully |
| Set header type | .html--.css--.png--.ico--.txt--.js--.ttf--.woff2--.json | Select the correct data type of the response data |
| Serve data from | SD card--Static text input--Dynamic text input | The data source. Whether the response data from the sd card or static text from the mask text box or dynamic text from input port |
| File location | Full file path. This option is enabled when the data is served from the SD card | |
| Contains .gz compressed files | Check--Uncheck | Check, when the files are gz compressed files |
| Text input | This enables when the data is served from a static text input. Insert the data on the text area |
This block is used when there are GET requests from the client.
This block handles the GET requests from the client. Before using this block, first initialize the server using HTTP Server Setup Block. The data to the input ports should be in string format.
Previous : HTTP Server Setup Block
Next : HTTP POST Handler Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Name of the handler | Specify the name for the current handler. It should not be repeated. | |
| URI | Specify the uri for the handler. In case the enable waildcard for this handler is enabled specify the base uri here. | |
| Enable wildcard for this handler | Check--Uncheck | Enable or disable the wildcard for this current handler. |
| Number of requests | 1 to 12 | Number of requests handle using the current handler. This will be always 1 when the wildcard is false in HTTP Server Setup block. |
| Output request data | Check--Uncheck | Enable this option to get the POST request body from the output port. |
| If request is | Specify the request to be handle (POST request body) | |
| Compare the whole request | Check--Uncheck | Compare the POST request body with the specified partially or fully |
| Set header type | .html--.css--.png--.ico--.txt--.js--.ttf--.woff2--.json | Select the correct data type of the response data |
| Serve data from | SD card--Static text input--Dynamic text input | The data source. Whether the response data from the sd card or static text from the mask text box or dynamic text from input port |
| File location | Full file path. This option is enabled when the data is served from the SD card | |
| Contains .gz compressed files | Check--Uncheck | Check, when the files are gz compressed files |
| Text input | This enables when the data is served from a static text input. Insert the data on the text area |
This block is used when there are POST requests from the client.
This block handles the POST requests from the client. Before using this block, first initialize the server using HTTP Server Setup Block. The data to the input ports should be in string format.
Previous : HTTP GET Handler Block
Next : xTaskCreate Block
HTTP Server Setup Block
HTTP GET Handler Block
HTTP POST Handler Block
Simple GET POST web page
Line chart widget with ADC values
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Enable wildcard | True--False | Enable or disable wildcard. By enabling this, server accepts multiple uri s in a single handler |
| Port number | Specify the port number which the server operates | |
| Core ID | 0--1--ANY | Select which core the server should operate |
| Stack size | Specify the stack size for the server task |
Use this block for the application which need to implement a custom http server using ESP32.
This block will initialize the http server with the given configuration.
Previous : NTP Block
Next : HTTP GET Handler Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| I2C driver port | 0--1 | Select driver port |
| Clock Frequency (kHz) | 100--400 | Specify clock speed of selected I2C module configuration. |
| SDA pin | Select pin for I2C SDA | |
| SDA internal pullup | Enable/disable internal pullup | |
| SCL pin | Select pin for I2C SCL | |
| SCL internal pullup | Enable/disable internal pullup | |
| Bytes write count | Specify number of bytes to write to I2C in a transaction. | |
| Bytes read count | Specify number of bytes to read from I2C in a transaction. | |
| Enable I2C scan device ESP log message. | Enable this to scan all i2c devices connected and display their salve addresses. To use this, feature a serial monitor is required. | |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time for the block |
Previous : SPI Block
Next : ADC Block
Target module Demo file : esp32_i2c_4_20mA_demo.slx
Host PC Demo file : udp_host_pc.slx
This demo shows how to use the I2C Block to get the reading from the external I2C ADC module and send the data to the host PC simulink model using a wireless UDP communication with Wireless Communication Block (HIL) in every 1s.
Once the host PC simulation is started the data reading from the ESP32 should be shown in the display block.
Previous : SPI demo
Next : ADC demo
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Input signal frame width | Specify the width of the frame of a single image in the video stream | |
| Input signal frame height | Specify the height of the frame of a single image in the video stream |
This block is used concatenate the RGB channels of the video stream from the Camera Block.
The way the ESP-WHO handle pixel data of an image is different from what Matlab Simulink does. Therefore the Camera Block transmit the video feed after splitting the image to three channels making it compatible with the Simulink Computer Vision Toolbox. After processing the image the three channels could be concatenated using this block.
Previous : System Time Block
Next: Memory Block
Enable user to create a Simulink block that can execute a custom C code.
Create a Simulink block that would act as a conditional statement block to toggle an LED.
Connect the potentiometer to the Analog Pin 33 and connect an LED to Digital Pin 2. Potentiometer should be connected in a way where the maximum input voltage is 3.3V and the minimum is 0V;
LED will toggle On and Off depending on the potentiometer reading.
toggle_led_condition_lib.slx
toggle_led_using_pot.slx
Previous : Scheduling mechanism in Waijung 2
Next : Create embedded web application with Aimagin Connect
GPIO Interrupt Block
Timer Interrupt Block
GPIO Interrupt demo
Timer Interrupt demo
This article introduces you to Waijung and Matlab & Simulink for uses in embedded system development, that can be much faster, easier, and more fun.
Computer and handheld devices (like smart phones, tablets) have revolutionized the world. Now we can play online games with our friends, share media, manage inventory, analyzing huge stock exchange data and many more things with these devices while sitting at a remote location. Having a video call on social media websites or doing online shopping is now quite easy but how these things are made possible.
Computer is a dump machine in-fact a very dump machine. Computers by itself cannot do anything. It don’t have power to make decisions. They are programmed so that they can act according to our ‘clicks’ and ‘touches’. To program a tablet or a computer to follow the instructions is not that straight forward. A house which looks very clean and beautiful is the result of hard efforts of the cleaner, home décor designer and the architect. An application ‘app’ available on our smart tablets – programmers and developers who work round the clock to deliver it.
A computer is an electronics device which works under the set of instructions stored in its own memory. From this definition we can analyses previously it was mentioned that computer is a dump device and it cannot do anything/make decisions at its own. Whatever is stored inside its own memory, it will work according to that. We can visualize the information process cycle of the computer or related device as in Figure 1.
Figure 1: Information Process Cycle
It is interesting to share information that a computer not only contains electric and electronic components but also some mechanical components [1]. These components are known as hardware. We can categorize the computer hardware as in Figure 2.
Figure 2: Computer hardware
An operating system (OS) is a set of programs containing instructions that work in conjunction with the hardware to perform the desired tasks. Main responsibilities of an OS are:
We can broadly classify the computers as:
A micro-controller is an integrated circuit with built-in Central Processing Unit (CPU), programming and non-programmable memory, input/output (I/O) ports, digital to analog convertor and vice versa.
Now a question can come in mind that what is the difference between a microcontroller and microprocessor of general purpose computer. Table 1 will explain this question.
Table 1: Comparison between Microprocessor and Microcontroller
An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints2. From the definition, it can be observed that an embedded system is different from general purpose computer but may contain similar components.
An embedded system can be called as a mini computer which has en ability to work in an intelligent standalone manner. Embedded systems are widely in used because they are:
Examples of embedded system are as follows:
MALTAB is developed by MathWorks which is a leading developer of mathematical computation software. MATLAB® is a high-level language and interactive environment for numerical computation, visualization, and programming [3]. The definition above have two keywords. When we refer to ‘high-level language’ the first thing which comes to mind should be: it is easy to do programming, have a lot of built-in functions and developing a program is simpler and more understandable to human beings. ‘Interactive environment for MATLAB refers to the availability of ‘Apps’, Graphical User Interface (GUI), multi-dimensional visualization.
MATLAB is used by mathematicians and statisticians as it helps them in solving linear and differential equations, applying optimization techniques to solve their problems, availability of statistical and machine learning algorithms for organizing, analyzing and modeling the data etc. MATLAB is used by engineers and scientists as it helps them in modeling an engineering system like vehicular area network, communication system, and aeronautical system. It helps them in signal and image processing, data visualization, control and fuzzy logic systems and many more. MATLAB is used by economists and financiers as functions in MATLAB are available for modeling an economic and financial data. Applications of MATLAB are not exhausted here. MATLAB can be used by any person who wants a computerized solution for his/her problem. As the programming in MATLAB is far easier, people often use MATLAB to write their program in MATLAB and then convert them into C or C++ in which writing code is quite hard as compared to MATLAB. More than 1 million people from industry and academia are using MATLAB – the language of technical computing. By now, reader can feel that MATLAB can be really helpful in solving a simple as well as complex problems.
Before some very basic examples are introduced in this section, it is assumed that the user has already installed MATLAB correctly and have some fundamental knowledge about programming. While installation, a user might have observed one thing i.e. installation time of MATLAB is significant. This is because of the richness of MATLAB in terms of libraries, built-in functions, variety of toolboxes, coders, blocksets etc. To start with, a MATLAB code to generate a sine wave is given and how we can visualize that sine wave.
This example shows how sine wave and cosine wave can be generated. Furthermore they are plotted against time to observe their phase difference. In order to do so, we need to know the two important things.
MATLAB Code
Figure 3: Plotting a sine and cosine wave
Moving a step forward, we know that a simple communication system consists of three entities i.e. transmitter, channel and the receiver. Channel can be wired (copper cable, twisted pair, optical fiber) or wireless (air, vacuum) [4]. Channel is the point where most of the noise is introduced in the transmitted signal. In the code below we do the following steps:
We can observe that even after the addition of the noise, FFT enables us to recover back the center frequency of the two signals. At the bottom of Figure 4, we can observe two peaks at 50Hz and 120Hz respectively which are the same as the signal frequency which we choose in the beginning.
MATLAB CODE
% Show the use of the FFT function for spectral analysis.
% Create signal at 50 Hz and 120 Hz
t = 0:.001:.25;
x1 = sin(2*pi*50*t);
x2 = sin(2*pi*120*t);
x = x1 + x2;
% Add some random noise
y = x + 2*randn(size(t));
subplot(611),plot(x1), title(‘Sine wave at 50 Hz’)
subplot(612),plot(x2), title(‘Sine wave at 120 Hz’)
subplot(613),plot(x), title(‘Sine wave at 50 Hz + 120 Hz’)
subplot(614),plot(y), title(‘Noisy time domain signal’)
% Finding the discrete Fourier transform
Y = fft(y,256);
% Compute the power spectral density
Pyy = Y.*conj(Y)/256;
f = 1000/256*(0:127);
subplot(615),plot(y), title(‘Noisy time domain signal’)
subplot(616), plot(f,Pyy(1:128)), title(‘Power spectral density’)
xlabel(‘Frequency (Hz)’)
Figure 4: Discrete Fourier transform and power spectral density calculations
No matter from which domain a researcher is, it is always important for him/her to represent his/her work in a meaningful way. Graphs are one excellent way of representing a large data which can yield a meaningful information. Fortunately, MATLAB is very rich in plotting graphs and have a lot of built-in functions. In the code below, a reader can find ways how a data can be represented using MATLAB. In this example, same data is represented in seven different ways i.e. scatter, stem, polar, error-bar, stair-step, bar and line plot.
MATLAB CODE
clear all, close all
% Scatter Plot
figure; load count.dat
scatter(count(:,1),count(:,2),’r*’)
xlabel(‘Number of Cars on Street A’);
ylabel(‘Number of Cars on Street B’);
title(‘Scatter Plot’)
% Stem Plot
figure; x = 0:0.1:4;
y = sin(x.^2).*exp(-x);
stem(x,y)
title(‘Stem Plot’)
% Polar Plot
figure; t=0:0.01:2*pi;
polar(t,abs(sin(2*t).*cos(2*t)));
title(‘Polar Plot’)
% Errorbar Plot
figure; x=-2:0.1:2;
y=erf(x); e = rand(size(x))/10;
errorbar(x,y,e);
title(‘Errorbar Plot’)
% Stairstep Plot
figure; x=0:0.25:10;
stairs(x,sin(x));
title(‘Stairstep Plot’)
% Bar Plot
figure; x = -2.9:0.2:2.9;
bar(x,exp(-x.*x));
title(‘Bar Plot’)
% Line Plot
figure; x=0:0.05:5;
y=sin(x.^2);
plot(x,y);
xlabel(‘Time’); ylabel(‘Amplitude’)
title(‘Line Plot’)
Figure 5: Different ways of representing data
Matlab is not only meant for doing some serious research but something romantic can also be created using few lines of MATLAB. Here is a sample code to create a heart.
MATLAB CODE
close all; clear all; clc v = -1.5:.02:1.5; [x,y,z] = meshgrid(v,v,v); w = (2*x.^2+y.^2+z.^2-1).^3-(1/10)*x.^2.*z.^3-y.^2.*z.^3; hp = patch(isosurface(w,0)); set(hp,’facecolor’,’r’,’edgecolor’,’none’) light; lighting phong; view(99,18)
For more examples, please refer to Section ‘List of Resources’.
By today, MATLAB has more than 40 toolboxes which allows scientist and researchers to complete their tasks with easy. The list of the toolbox can be found from the following link.
http://www.mathworks.com/products/
In order to check which toolboxes, blocksets and version of MATLAB is installed in the computer, user need to type command ‘ver’ in command line.
Figure 7: Using command ver to check MATLAB version and installation products
Simulink is a block diagram environment for multi-domain simulation and Model-Based Design. It supports simulation, automatic code generation, and continuous test and verification of embedded systems [5]. Like MATLAB, Simulink was also developed by Mathworks. Its principal interface is a graphical block tool and a customizable set of block libraries. Simulink can be used in conjunction with the MATLAB. Capabilities of Simulink are as follows:
Figure 8: Simulink capabilities
Aimagin is specialized in utilizing the capability of Simulink to connect with hardware. The later part of this tutorial will leads us to connect Aimagin hardware with Simulink but before tutorial goes into that detail it is very important to understand the Simulink first.
In order to run Simulink, user need to type simulink in the MATLAB command window. MathWorks also provides an icon to Simulink but the icon position and colors may vary with the different versions of MATLAB so for the beginning it is preferred to go by typing Simulink in MATLAB command window which works on all the version of MATLAB. The result is shown in Figure 9.
Figure 9: Starting Simulink
A list of block library will appear. User can select a block of desired characteristics from these libraries. The most commonly use block libraries are:
To create a new model, the user need to do go to File -> New ->Model. In order to open an existing model, user need to go to _ File ->Open ->_ Specify the model location on the hard disk.
Figure 10: Opening a new model
When we click on Model, a new window will open which is shown below in Figure 11.
Figure 11: New model in Simulink
Now, we are all set to create a model. We need to first plan, what actually we want to build and what are the components required. Please keep in mind that just by simply connecting the blocks in the model, things will not work. Input of the second block must be matching with the output of the first block and so on. Indeed drawing modeling in Simulink is far easier than doing programming but don’t think Simulink like Microsoft Visio. Don’t get disappointed if while running the model, you get some error. Read about the block properties, the background knowledge of relevant field and the nature of input/output signals. As like other learning tools, beginning is little difficult but things becomes easier with the passage of time. So we start with a simple case and our agenda is to create a detailed digital communication system.
We start with the simplest case. Open a new model. Save a model with a legit name. Now a reader should think before going further, what blocks are required in order to create and sine wave and see the created sine wave. The answer is very simple. Two things i.e. something which can generate a sine wave and something which is like a oscilloscope in the labs to see it. We search for these two items in ‘Simulink Library Browser’. When right choice of component is found, simply drag that block to the new model created.
Figure 12: Dragging appropriate components to the model
Now both the required blocks are with us. Now it’s the time to see if it is possible that by doing so simple task, sine wave can be created and observed. Click on ‘play’ button or Ctrl + T. Simulink will start compiling and when it’s done, double click on scope button the observe the output which is shown in Figure 13. Please note that the properties of Sine wave block (or any other block) can be customized by double click on the block. Similarly, model configuration parameters can be changed from Simulation -> Model Configuration Parameters.
Figure 13: Observing the sine wave
Please note that in order to obtain the results in Figure 13, following customization has been done.
Figure 14: Setting model configuration parameters
Figure 15: Scope parameter properties configuration
Now, we can move forward quickly. For the next example, we require the following blocks.
These blocks are arranged in the following order as shown in Figure 16 and the output is shown in Figure 17.
Figure 16: Integrating a sine wave
Figure 17: Output of the block diagram of Figure 16
Yellow line is for the output after passing through gain and integrator and purple line is for the sine wave generated. It can be observed that it is a simple procedure to apply gain and applying little complex mathematical operation like integration.
Figure 18 shows the inverted pendulum on the cart. This is a typical engineering problems since ages and it can be modeled and visualized in Simulink with so ease.
Figure 18: Inverted pendulum on the cart
For more examples, please refer to Section ‘List of Resources’.
After analyzing some program written in MALTAB, a question may come in reader’s mind that in which programming language MATLAB is written? The answer to this question is not that straightforward. MATLAB is not written in a single programming language but in many programming languages which are:
MATLAB/Simulink have a lot of advantages which engineers, researchers, scientists and students can enjoy [6].
It uses a large amount of memory and slow down the computer.
From the discussion above, reader can realize that the programming in C/C++/Assembly is not very easy however MATLAB/Simulink is a powerful tool to overcome this issue. Specifically talking about Simulink, things can be done by connecting the respective blocks without writing even a single line of code. While designing and analyzing a system like intelligent control system/signal processing/communication system etc. MATLAB/Simulink gives wings i.e. design and analysis process is simple and easy but comprehensive. Simulation using MATLAB/Simulink tools will save time and cost. Furthermore, detailed analysis gives an opportunity to avoid any unwanted situation.
For the real system implementation using MATLAB/Simulink tool, there are two major concerns.
In order to connect hardware with Simulink, Aimagin has made a customized blockset named ‘Waijung’. This provide an opportunity the Aimagin hardware with the Simulink and a user can realize a real system. So with Waijung blockset, from design to implementation, the whole process is fast, easy, fun and not forget to mention …NO C/C++ code is required. We explain the advantage of our blockset with an example. For example a user wants to make a chair. In order to make a chair he/she needs a hammer, nails, sandpaper and wood. Now there are two options available.
Option 1: Make hammer, nails and sandpaper yourself. Go to the forest to cut tree and bring wood. When everything is done, start making chair
Option 2: Buy/use already available hammer, nails, sandpaper and wood in the market and make a chair
Indeed option 2 is better than option 1 in terms of time and skills required.
MATLAB gives a tool to convert a MATLAB written code in C (and other languages) which can fit well in time sensitive applications. Generated code from Matlab contains more overhead than hand coding but the former one is faster a suitable for rapid prototyping. A detailed explanation how a C code can be generated from MATLAB algorithm is given in the following link.
http://blogs.mathworks.com/loren/2011/11/14/generating-c-code-from-your-matlab-algorithms/
Readers should not get an impression that merely connecting Aimagin hardware via USB with a computer will get everything done. For example if a user want to add two numbers using a calculator, then he must know that he should enter first number then press + button and then enter the second number. At the end, the user should press = button the get the output. Similarly using Waijung with hardware, the user must know the mathematics/equations involved while realizing a system, how to use the tools, how to connect the circuit, how circuit works etc.
Currently significant literature is available online and the company is constantly adding more and more literature, examples, tutorials and videos so that the users can benefit more from Aimagin products. To get hands on and for some mini projects, the users can refer to blog.aimagin.com where they can find more than 20 sample projects and tutorials.
Quick reference for sample project is as under
http://aimagin.com/blog/topics/sample-project-th/?lang=th
Quick reference for mini projects
http://aimagin.com/blog/mini-project-kmutnb-mechatronics-56/?lang=th
Quick reference for tutorials
http://aimagin.com/blog/topics/tutorials-th/?lang=th
Reference Manual about Waijung can be accessed from the below mentioned link. From here Waijung blockset can be downloaded.
Video tutorials which gives a great insight about our product can be accessed from
Information about Aimagin previous RapidSTM32 block set can be found from
A large resources in terms of tutorials, examples, videos books etc. are available. For instance
Here is the list of few tutorials on the MATLAB. Please note that this is not a complete list but only very few references how to get started with MATLAB. After gaining the basic knowledge, the user can search for more resources of the web.
http://www.mathworks.com/academia/student_center/tutorials/launchpad.html
http://www.mathworks.com/academia/student_center/tutorials/?s_tid=gn_ac_sv_tu
http://www.math.utah.edu/lab/ms/matlab/matlab.html
http://ctms.engin.umich.edu/CTMS/index.php?aux=Basics_Matlab
http://www.math.mtu.edu/~msgocken/intro/intro.html
http://www.cs.utexas.edu/~grauman/courses/spring2011/matlab.pdf
http://www.matlabtutorials.com/
http://www.youtube.com/watch?v=QbRLoMH9a24
Same is true for the tutorials for Simulink. The list goes on and here are only few…
http://www.mathworks.com/academia/student_version/learnsimulink_sp3.pdf
http://web.mit.edu/acmath/matlab/course16/slides_16.06_16.07_matlab_simulink.pdf
http://classes.soe.ucsc.edu/cmpe242/Winter14/Simulink.pdf
http://www.youtube.com/watch?v=TfXBw51xKr0
http://www.tufts.edu/~rwhite07/PRESENTATIONS_REPORTS/simulink.pdf
http://ocw.usu.edu/Electrical_and_Computer_Engineering/Signals_and_Systems/Simulink_Tutorial.html
Mathworks website is the best tool to search for MATLAB/Simulink books. More than 1500 titles are available.
http://www.mathworks.com/support/books/
http://www.orchardpublications.com/1934404071ex.pdf
Waijung is a valuable addition to MATLAB/Simulink blockset. Our company works in a modern philosophy ‘Make it work now – optimize later’. Our ultimate goal is to en-power the students to create more complex algorithms in less time. This will be more beneficial to the industry in terms of better products, more values and more business.
With the ambition of making complex and hard to understand process simple, currently our company is mainly focusing on (but not limited to) digital signal and image processing, network monitoring and control systems. We really appreciate new innovative ideas from our users. In a very short period of time, our products are being used and appreciated by good number of researchers and they are quite happy and contented with our products. Some of the testimonials from our valuable users can be found from the following link
https://www.aimagin.com/customer_testimonials/
We hope that with our products students will be able to learn and use industrial standards tools. From the students our hopes are:
Users can use the following channels to ask question
https://www.facebook.com/pages/Aimagin/263308030369020
[1]. Shelly, Gary, Glenda Gunter, and Randolph Gunter. Teachers Discovering Computers: Integrating Technology in a Connected World. Cengage Learning, 2011.
[2]. http://www.barrgroup.com/Embedded-Systems/Glossary-A
[3]. http://www.mathworks.com/products/matlab/
[4]. Saadi, M., et al. “Visible light communication: opportunities, challenges and channel models.” International Journal of Electronics & Informatics 2.1 (2013).
[5]. http://www.mathworks.com/products/simulink/
[6]. http://www.csee.wvu.edu/~xinl/courses/ee465/programming_tips.pdf
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| LEDC Timer | LEDC_TIMER_0--LEDC_TIMER_1--LEDC_TIMER_2--LEDC_TIMER_3 | Select the timer |
| Duty Resolution | LEDC_TIMER_1_BIT to LEDC_TIMER_20_BIT | Select the duty resolution |
| PWM Frequency (Hz) | Select the PWM frequency | |
| Timer Speed Mode | LED_HIGH_SPEED_MODE--LED_LOW_SPEED_MODE | Select the LEDC driver speed mode |
| Source Clock | If the value for this parameter is LEDC_AUTO_CLOCK, the clock will be selected automatically | |
| Hide unused channel configurations | on--off | The channels assigned Do not use will be hidden |
| hpoint | specify the hpoint | |
| Duty Cycle Mode | Using hardware--Using software | Select the duty cycle mode. the Duty cycle mode will also change the input method (from mask or from input port) for this parameter |
| Fade function | ledc_set_fade_time_and_start--ledc_set_fade_step_and_start | In the hardware mode the user will be able to select the fade function to be used |
| Target Duty | Specify the target duty. The maximum of this parameter depend on the timer configurations. Check reference for more information | |
| Max Fade Time (milliseconds) | Specify the time duration for the fade | |
| Fade Mode | LEDC_FADE_NO_WAIT--LEDC_FADE_DONE | Select fade mode |
| Scale | Select scale | |
| Cycle Number | Select cycle number |
This block is designed to control LED intensity using PWM signals. This block could be used for other similar applications involving PWM signal generation as well.
Check LED Control documentation of ESPRESSIF
Previous : SD Card Block
Next : MCPWM Block
Demo file : esp32_ledc_demo.slx
This demo uses LEDC Block to configure four LEDs to repeat four sequences.
Previous : Circular Buffer demo
Next : Automatic Logging of data to Google sheets from ESP32
Demo file : esp32_http_server_demo2.slx
This demo shows how to use HTTP Server Setup Block, HTTP GET Handler Block and HTTP POST Handler Block by using the custom html web page with a line graph widget. Addition to those blocks, the WiFi Block is used to initialize the wifi in AP mode to access the http server, SD Card Setup Block is used to initialize the SD card to serve the files and ADC Block to read adc pin (GPIO36).
Note : First copy the source_files2.7z and extract the files to the SD card and insert in to the ESP32 module.
Once the IP address is accessed using the web browser, the web page is as below
The client will request the ADC data from the ESP32 server in every one second and update the graph according to the data.
Source files : source_files2.7z
Previous : Simple GET POST web page
Next : Circular Buffer demo
This application will allow you to understand how the simple model is uploaded in to the hardware of user's preference. As the introductory sample the blink LED example is explained here,
Note : No need to setup the following hardware configuration, if the ESP32 module has onboard LED which is connected to the GPIO2.
Connect the hardware in the following order. Connect an LED to digital pin 2 of your ESP32 through 1k ohm.
Step 01
Open Matlab . Change the current folder to the directory where you want to create the model. Click Simulink.
Step 02
Click Blank Model. Save the new model in any name you want without space to avoid any errors as '******.slx'
Step 04
Re-arrange the blocks according to the picture by connecting the two blocks . For more details about Building, Simulating and connecting a Simple Simulink Model
Step 05
Change the block configuration parameters as shown in picture by double clicking on each block. Make sure the COM port hardware is connected to the same COM port. Change the ESP32 Flash Size according to the hardware connected, in this example select 4MB. Pin 2 is assigned as the digital output pin for this example in Digital Out blockset. The parameter values are adjusted to get frequency of 1 Hz. 
Step 06
Now upload the code. Go to APPS tab and click Embedded Coder. After C CODE tab opens press the drop down menu to UPLOAD the code.
The LED connected to pin5 through 1k ohm resistor will start blinking at 0.5 Hz frequency. The target setup blockset allow you to connect the model with the hardware. The frequency is generated with used of the pulse generator, the digital out blockset allow the signal to be transmited to the LED. In this example the output pin is assigned to GPIO2 in the digital out blockset.
The following blocks have been used in this model.
Click to download the HelloWorld.slx model file.
In case the user wants to monitor run time serial data, the following options would serve.
Previous: Simulate LED toggle
Next: How to use demo file?
รูปแบบโครงสร้างการตั้งค่าแบบสมบูรณ์
setParameter('my_map', 'Data', {
source: {
table: {
sql: `SELECT * FROM TABLE`, //sql สร้างตาราง - จำเป็น
database: 'sqlite',//[sqlite,clickhouse] - // ชนิด database - จำเป็น
pk: "rowid",//primary key ของตาราง - optional
layer: "layer",//layer ของ marker ผูกกับคอลัมน์ของตาราง - optional
column: [ //เป็นคอลัมน์ที่จะแสดงใน popup เวลา user click ที่ marker - optional
{
name: "lat",
label: "ละติจูด"
}, {
name: "lng",
label: "ลองกิจูด"
}, {
name: "area",
label: "พื้นที่"
}]
},
position: {
lat: "lat", // ชื่อคอลัมน์ที่เก็บ Latitude - จำเป็น
lng: "lng" // ชื่อคอลัมน์ที่เก็บ Latitude - จำเป็น
},
tooltip: { //กำหนด tooltip ให้กับ markerได้
column:'detail', //เป็นชื่อคอลัมน์ที่นำมาทำ tooltip
permanent:false, //แสดงเมื่อ hover ถ้าเป็น true คือ แสดงตลอด
direction:'auto' //ตำแหน่งของ tooltip มี 'top', 'left', 'right', 'bottom', 'auto'
},
layer: { //กำหนด layer label กับ color marker ได้ หรือใช้ marker เป็นภาพโดยกำหนด url ได้ ถ้าไม่มี layer แต่พบว่ามีการกำหนดจะใช้ column[0] แทน และกำหนด markerOpacity ได้
column:[{name:"layer-1", label:"LAYER 1", markerColor:"red"}, {name:"layer-2", label:"LAYER 2", markerColor:"green", markerOpacity:0.3}, {name:"layer-3", label:"LAYER 3", markerUrl:"http://maps.google.com/mapfiles/kml/shapes/marina.png"}]
},
circle: {
area: "area_col", // ชื่อคอลัมน์ที่เก็บพื้นที่ของวงกลม - optional
fillColor: "fillColor_col", // ชื่อคอลัมน์ที่เก็บสีของวงกลม - optional
fillOpacity: "fillOpacity_col", // ชื่อคอลัมน์ที่เก็บความทึบของวลกลม - optional
opacity: "opacity_col", // ชื่อคอลัมน์ที่เก็บความทึบของเส้นรอบวง - optional
color: "color_col", // ชื่อคอลัมน์ที่เก็บสีของเส้นรอบวง - optional
weight: "weight_col" // ชื่อคอลัมน์ที่เก็บน้ำหนักของเส้นรอบวง - optional
}
},
custom: {
circle: {
area: 100, // - กำหนดขนาดของวงกลมทุกวง - optional
fillColor: "#FF0000", // - กำหนดสีของวงกลมทุกวง - optional
fillOpacity: 0.35, // - กำหนดความทึบของวงกลมทุกวง - optional
opacity: 0.8, // - กำหนดความทึบของเส้นรอบวงทุกวง - optional
color: "#FF0000", // - กำหนดสีของเส้นรอบวงทุกวง - optional
weight: 1 // - กำหนดน้ำหนักของเส้นรอบวงทุกวง - optional
},
popup: {
callback: function({data}) {//สำหรับวาด popup เอง โดย return html string ออกไป data เป็น json ของ row ที่ select มา
return "<p>test</p>"
}
},
},
default: {
circle: { // หากไม่มีการผูกวงกลมกับ column ใน source.circle และไม่มีการกำหนด custom.circle ดังนั้น default.circle จะถูกใช้
area: 314, // - ค่า default พื้นที่วงกลมรัศมี 10 เมตร - optional
fillColor: "#FF0000", // - ค่า default สีของวงกลม - optional
fillOpacity: 0.35, // - ค่า default ความทึบของวงกลม - optional
opacity: 0.8, // - ค่า default ความทึบของเส้นรอบวง - optional
color: "#FF0000", // - ค่า default สีของเส้นรอบวง - optional
weight: 1 // - ค่า default น้ำหนักของเส้นรอบวง - optional
}
},
cluster: {
disabled:false //true/false ใช้หรือไม่ใช้ cluster ถ้าไม่ใช้ จะแสดงไม่เกิน 1000 จุด เพราะไม่อย่างนั้นแผนที่จะรับไม่ได้ - optional
Nx:100, // เป็นจำนวนช่องตามแกน x เพื่อทำ cluster - optional
Ny:100, // เป็นจำนวนช่องตามแกน y เพื่อทำ cluster - optional
min:20, // เป็นจำนวนตำแหน่งต่ำสุดที่จะรวมเป็น cluster หากต่ำกว่าจำนวนนี้ จะไม่ถูกกระจายเป็น marker และ อาศัยการทำ cluster บน client แทน - optional
},
view: {
visible:true //true/false แสดงหรือซ่อนแผนที่ - optional
center: [13.736717, 100.523186], // จุดศูนย์กลางของแผนที่ ในรูปแบบ [lat, lng] - optional
zoom:5 //ค่าการ zoom - optional
}
});
การใช้งานในขั้นพื้นฐานสุดต้องใช้ sql, database, lat, lng
ส่วน พื้นที่วงกลม (area), สีของวงกลม (fillColor), ความทึบของวงกลม (fillOpacity), สีของเส้นรอบวง (color), ความทึบของเส้นรอบวง (opacity), น้ำหนักของเส้นรอบวง (weight) จะขึ้นกับค่า default ของระบบ
setParameter('my_map', 'Data', {
source: {
table: {
sql: `SELECT * FROM TABLE`, //sql สร้างตาราง
database: 'sqlite',//[sqlite,clickhouse] // ชนิด database
},
position: {
lat: "lat", // ชื่อคอลัมน์ที่เก็บ Latitude
lng: "lng" // ชื่อคอลัมน์ที่เก็บ Longitude
}
}
});
หากต้องการผูกค่า พื้นที่วงกลม (area), สีของวงกลม (fillColor), ความทึบของวงกลม (fillOpacity), สีของเส้นรอบวง (color), ความทึบของเส้นรอบวง (opacity), น้ำหนักของเส้นรอบวง (weight) กับคอลัมน์ให้เพิ่ม field ชื่อ circle ภายใต้ source
setParameter('my_map', 'Data', {
source: {
table: {
sql: `SELECT * FROM TABLE`, //sql สร้างตาราง - จำเป็น
database: 'sqlite',//[sqlite,clickhouse] - // ชนิด database - จำเป็น
},
position: {
lat: "lat", // ชื่อคอลัมน์ที่เก็บ Latitude - จำเป็น
lng: "lng" // ชื่อคอลัมน์ที่เก็บ Latitude - จำเป็น
},
circle: {
area: "area_col", // ชื่อคอลัมน์ที่เก็บพื้นที่ของวงกลม - optional
fillColor: "fillColor_col", // ชื่อคอลัมน์ที่เก็บสีของวงกลม - optional
fillOpacity: "fillOpacity_col", // ชื่อคอลัมน์ที่เก็บความทึบของวลกลม - optional
opacity: "opacity_col", // ชื่อคอลัมน์ที่เก็บความทึบของเส้นรอบวง - optional
color: "color_col", // ชื่อคอลัมน์ที่เก็บสีของเส้นรอบวง - optional
weight: "weight_col" // ชื่อคอลัมน์ที่เก็บน้ำหนักของเส้นรอบวง - optional
}
}
});
หากต้องกำหนดค่า พื้นที่วงกลม (area), สีของวงกลม (fillColor), ความทึบของวงกลม (fillOpacity), สีของเส้นรอบวง (color), ความทึบของเส้นรอบวง (opacity), น้ำหนักของเส้นรอบวง (weight) ให้เหมือนกันทั้งหมด กำหนดผ่าน custom ได้ทันที โดยจะ override ค่า default และ หากมีการผูกกับคอลัมน์อยู่ก็จะถูกปรับด้วย
setParameter('my_map', 'Data', {
custom: {
circle: {
area: 100, // - กำหนดขนาดของวงกลมทุกวง
fillColor: "#FF0000", // - กำหนดสีของวงกลมทุกวง
fillOpacity: 0.35, // - กำหนดความทึบของวงกลมทุกวง
opacity: 0.8, // - กำหนดความทึบของเส้นรอบวงทุกวง
color: "#FF0000", // - กำหนดสีของเส้นรอบวงทุกวง
weight: 1 // - กำหนดน้ำหนักของเส้นรอบวงทุกวง
}
}
});
setParameter('my_map', 'Data', {
custom: {
circle: {
area: null,
fillColor: null,
fillOpacity: null,
opacity: null,
color: null,
weight: null
}
}
});
ใช้ marker icon ที่มีสีจาก https://github.com/pointhi/leaflet-color-markers
มีตัวอย่าง marker icon ของ google เพิ่มเติมที่ใช้กับ kml ใช้โดยอิง url
http://kml4earth.appspot.com/icons.html
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Timer Tab | Timer 0--Timer 1--Timer 2 | Each tab has separate configuration parameters for each timer |
| Activate Timer | on--off | Each timer if in use should be activated by this checkbox |
| Frequency | Select the PWM frequency | |
| Duty cycle of PWMxA/PWMxB | This is the initial duty cycle of PWMxA/B. The user can change this value later using esp32_mcpwm_func block | |
| Counter Mode | MCPWM_UP_COUNTER--MCPWM_DOWN_COUNTER--MCPWM_UP_DOWN_COUNTER | Select counter mode. Check References for more details |
| Duty Mode | MCPWM_DUTY_MODE_0--MCPWM_DUTY_MODE_1--MCPWM_HAL_GENERATOR_MODE_FORCE_LOW--MCPWM_HAL_GENERATOR_MODE_FORCE_HIGH | Select duty mode. Check References for more details |
| Enable Dead Time | on--off | Enable/disable Dead Time feature |
| Dead Time Mode | MCPWM_DEADTIME_BYPASS--MCPWM_BYPASS_RED--MCPWM_BYPASS_FED--MCPWM_ACTIVE_HIGH_MODE--MCPWM_ACTIVE_LOW_MODE--MCPWM_ACTIVE_HIGH_COMPLIMENT_MODE--MCPWM_ACTIVE_LOW_COMPLIMENT_MODE--MCPWM_ACTIVE_RED_FED_FROM_PWMXA--MCPWM_ACTIVE_RED_FED_FROM_PWMXB | Select Dead Time Mode. Check References for more details. |
| Rising Edge Delay | Enter the rising edge delay | |
| Falling Edge Delay | Enter the falling edge delay | |
| Activate CAPx | on--off | Enable/disable capture component |
| Capture Edge | MCPWM_POS_EDGE--MCPWM_NEG_EDGE--MCPWM_BOTH_EDGE | Select capture edge |
| Number of Pulses | Enter the number of pulses |
This block is used to generate PWM signals to control motors.
ESP32 has two MCPWM units which can be used to control different types of motors. Each unit has three pairs of PWM outputs.
MCPWM_CONFIG is the configuration block that would enable user to configure everything in one MCPWM Unit. MCPWM_FUNC consists various API's created by ESPRESSIF to drive the PWM signal. Therefore the user can have one MCPWM_CONFIG block to configure all the components in a MCPWM unit and several MCPWM_FUNC blocks to create a sequence to drive the motor.
The current version (waijung2_20.11b) of the MCPWM_CONFIG block only allow user to configure one MCPWM Unit per model.
Check MCPWM documentation of ESPRESSIF
Previous : LEDC Block
Next : Aimagin Connect Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Mode | Setup--Read--Write | Select the operation mode |
| Buffer Name | Select the name of the buffer which is going to hold the image data | |
| Inherit from the camera block | The Image Source Parameters Will be automatically acquired from the camera block | |
| Image format | The format of the image | |
| Frame Width | Width of the image frame | |
| Frame Height | Height of the frame | |
| Buffer Size | Buffer Size = Frame width * Frame height * 3 |
This block is used to temporarily hold an image in the external RAM of ESP32.
Previous : Image Concatenate Block
Next: String Processing Block
Mesh Setup
Mesh Transmitter
Mesh Receiver
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Output Data Buffer Size | 32--64--128--256--512--1024 | Select the output buffer size. |
This block can be used to data from other nodes in a mesh network.
Previous : Mesh Transmitter
Next : Printf Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Mesh ID | Enter a unique mesh ID. | |
| Mesh AP Authentication Mode | WIFI_AUTH_OPEN--WIFI_AUTH_WPA_PSK--WIFI_AUTH_WPA2_PSK--WIFI_AUTH_WPA_WPA2_PSK | Select the authentication mode. |
| Mesh AP Password | Enter the mesh password. | |
| Mesh AP Connections | Enter the number of nodes in the mesh. | |
| Mesh Max Layers | 1 to 6 | Enter the maximum number of layers which the node hierarchy should be adjusted to. |
| Router SSID | Enter the router SSID. | |
| Router Password | Enter the router password. | |
| Channel | Enter the router channel. | |
| Mesh Network Status | Check--Uncheck | Enable/disable status output. |
This block can be used to setup a mesh network between several ESP32 devices.
Each node in the mesh network should contain this block. This will automatically identify the other nodes in the network and set the hierarchy according to the user configurations depending on the signal strength from router. If ‘Mesh Network Status’ is ‘Checked’ it will indicate the completion of this setup process.
Previous : Camera Block
Next : Mesh Transmitter
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Number of Receivers | Enter the number of nodes at the receiving end. |
This block can be used to data from one node to other nodes in a mesh network.
Previous : Mesh Setup
Next : Mesh Receiver
This tutorial will show how to edit the C code that gets generated by using the Waijung2 block-set. The user will also be introduced to ESP-IDF development environment as well.
Using Visual Studio Code extension
Previous : Develop web application for ESP32 to setup WiFi Station mode
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| SNTP Server name | Enter the SNTP server name | |
| Time Zone | Enter the time zone | |
| Country | Enter the country |
Simple Network Time Protocol (SNTP) block can be used to get the time from any SNTP server.
Previous : OTA Block
Next : HTTP Server Setup Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Mode | AP Mode--Station Mode | Select mode. |
| Use Aimagin Connect | Check--Uncheck | |
| Sample time (sec) | -1 (inherited) or specify | Specify sample time. |
This block is used to upgrade firmware over the air.
This block requires WiFi Block to function. Depending on the WiFi configuration (AP or STA), ‘Mode’ in this block should be set. In Station mode the user can input the direct download URL of the update file saved in any server (Example: Google Drive).
In the AP mode the file can be uploaded from the client’s device. If ‘Use Aimagin Connect’ is ‘Unchecked’, when the client tries to access the web server default web page will be prompted where the user can upload the update file from host device. The URL is: http:// [ assigned IP for esp32 ]/OTA_upgrade/
If ‘Checked’, it means the user has added the firmware upgrade API to their custom web application thus user can use it to upload the file. However, for this method to work ‘esp32_aimagin_connect’ block should be available in the program model file.
Previous : SQLite NonRetrieveData
Next : NTP Block
Patch update Advanced_PWM
Description:
- Fix CH2 pins E11/B14 to A9/E11
Instruction:
1. Replace (Overwrite) the following file in to directory: \waijung_17_03a\targets\stm32f4_target\stm32f4\src\blocks
1.1 stm32f4_advanced_pwm_callback.p
Patch update Ethernet Link Setup block
Description:
- Fix AutoNegotiation problem. The delay time between Link reset command and AutoNegotiation command, chaged from 0xFF to 0xFFF.
Instruction:
1. Replace (Overwrite) the following file in to directory: \waijung_17_03a\utils\lwip-app\inc
1.1 stm32f4x7_eth_conf.h
Patch update Ethernet Link Setup block
Description:
- Add configuration for Enable/ Disable AutoNegotiation. Note: if AutoNegotiation disabled, "Speed" and "Duplex mode" can be select manually.
Instruction:
1. Replace (Overwrite) the following files in to directory: \waijung_17_03a\src\blocks
1.1 waijung_ethernet_inf.tlc
1.2 waijung_ethernet_inf_callback.p
1.3 waijung_webserver.mdl
Patch update usbconverter_n_connect
Description:
- Apply to waijung 17.03a
- Fix crashing when communicate with USART block.
Instruction:
1. Close MATLAB program, if it running.
2. Replace (Overwrite) the following file in to directory: \waijung_17_03a\src\blocks
2.1 amg_usbconverter_n_connect.mexw32
2.2 amg_usbconverter_n_connect.mexw64
Fix encoder read block error
Description:
- Apply with waijung 17.03a
Instruction:
1. Close MATLAB program, if it running.
2. Un-zip file.
3. Replace (overwrite the exising) the following files into directory: "\waijung17_03a\targets\stm32f4_target\stm32f4\src\blocks"
3.1 stm32f4_encoderread_callback.p
const pivotWidgetID = "pivot"
// ตั้งข้อมูลผ่านชื่อ table จาก Sqlite
setParameter(pivotWidgetID ,"Table",{tableName:"ข้อมูลตารางคนขอเข้าประเทศ2"})
// ตั้งข้อมูลผ่านชื่อ table จาก Sqlite และเปลี่ยนชื่อคอลัมป์ "ลำดับรวม" ให้เป็นชื่อ "Number"
setParameter(pivotWidgetID ,"Table",{tableName:"ข้อมูลตารางคนขอเข้าประเทศ2",headerLabels:[{colName:"ลำดับรวม",label:"Number"}]})
// ตั้งข้อมูลผ่านชื่อ table จาก clickhouse
setParameter(pivotWidgetID ,"Table",{tableName:"aa_test",database:"clickhouse"})
// ตั้งข้อมูลผ่าน query statement จาก sqlite
setParameter(pivotWidgetID ,"Table",{sql:"SELECT * FROM ข้อมูลตารางคนขอเข้าประเทศ2 LIMIT 100"})
// ตั้งข้อมูลผ่าน query statement จาก clickhouse
setParameter(pivotWidgetID ,"Table",{sql:`SELECT * FROM "aa_test" LIMIT 200`,database:"clickhouse"})
const pivotWidgetID = "pivot"
// ตั้งค่า config จาก string ที่ได้จาก getParameter(pivotWidgetID ,"Config")
setParameter("pivot","Config",`{"orders":{},"mode":[{"id":0,"col":0,"column":"ลำดับรวม","name":"Count of ลำดับรวม"}],"headers":[{"id":0,"label":"ลำดับรวม","selected":false,"filterSelected":false},{"id":1,"label":"ลำดับ","selected":false,"filterSelected":false},{"id":2,"label":"ชื่อเรือ","selected":false,"filterSelected":false},{"id":3,"label":"IMO","selected":false,"filterSelected":false},{"id":4,"label":"เที่ยวเรือ","selected":false,"filterSelected":false},{"id":5,"label":"ประเภทเรือ","selected":false,"filterSelected":false},{"id":6,"label":"ท่าเรือสุดท้ายก่อนเข้าไทย","selected":false,"filterSelected":false},{"id":7,"label":"สัญชาติเรือ","selected":false,"filterSelected":false},{"id":8,"label":"ท่าเรือที่เทียบท่า","selected":false,"filterSelected":false},{"id":9,"label":"จังหวัดที่เทียบท่า","selected":false,"filterSelected":false},{"id":10,"label":"วันที่แจ้งว่าจะเข้าไทย","selected":false,"filterSelected":false},{"id":11,"label":"วันที่มีการยืนยันจากศรชลภาค","selected":false,"filterSelected":false},{"id":12,"label":"การยืนยัน","selected":false,"filterSelected":false},{"id":13,"label":"คำนำหน้าชื่อ","selected":false,"filterSelected":false},{"id":14,"label":"ชื่อสกุลภาษาไทย","selected":false,"filterSelected":false},{"id":15,"label":"ชื่อสกุลภาษาอังกฤษ","selected":false,"filterSelected":false},{"id":16,"label":"หมายเลขบัตรประจำตัวประชาชน","selected":false,"filterSelected":false},{"id":17,"label":"หมายเลขหนังสือเดินทาง","selected":false,"filterSelected":false},{"id":18,"label":"หมายเลขSeamanBook","selected":false,"filterSelected":false},{"id":19,"label":"จังหวัด","selected":false,"filterSelected":false},{"id":20,"label":"อำเภอ","selected":false,"filterSelected":false},{"id":21,"label":"ตำบล","selected":false,"filterSelected":false},{"id":22,"label":"ที่อยู่ในประเทศ","selected":false,"filterSelected":false},{"id":23,"label":"เบอร์โทรศัทพ์","selected":false,"filterSelected":false},{"id":24,"label":"เบอร์โทรศัทพ์สำรอง","selected":false,"filterSelected":false},{"id":25,"label":"ผู้ที่ติดต่อได้","selected":false,"filterSelected":false},{"id":26,"label":"เบอร์ติดต่อของผู้ที่ติดต่อได้ในไทย","selected":false,"filterSelected":false},{"id":27,"label":"เลขที่หนังสือ","selected":false,"filterSelected":false},{"id":28,"label":"มีสภาพร่างกายแข็งแรง","selected":false,"filterSelected":false},{"id":29,"label":"มีอุณหภูมิร่างกายต่ำกว่า37จุด5เซลเซียส","selected":false,"filterSelected":false},{"id":30,"label":"ไม่มีอาการไอมีน้ำมูกเจ็บคอหอบหืดอย่างใดอย่างหนึ่ง","selected":false,"filterSelected":false},{"id":31,"label":"โรคประจำตัวโรคเรื้อรังที่เป็น","selected":false,"filterSelected":false},{"id":32,"label":"ยาที่ใช้ประจำ","selected":false,"filterSelected":false},{"id":33,"label":"localquarantine","selected":false,"filterSelected":false},{"id":34,"label":"PROVINCE","selected":false,"filterSelected":false},{"id":35,"label":"หมายเหตุ","selected":false,"filterSelected":false}],"filters":{},"rowHeaders":["จังหวัดที่เทียบท่า"],"colHeaders":["สัญชาติเรือ","ประเภทเรือ"],"filterHeaders":[],"chart_mode":{"id":0},"page":{"name":"test-pivot","id":"pivot","configType":"pivot.config"},"isAutoUpdate":true,"isShowBlank":false,"source":"pivot.config"}`)
// รับข้อมูล config แบบ string
getParameter(pivotWidgetID ,"Config")
const pivotWidgetID = "pivot"
// เปิดหน้า File upload ให้เลือกไฟล์ config ที่จะใช้จากไฟล์ในเครื่อง
setParameter(pivotWidgetID ,"ConfigFile")
// โหลดไฟล์ config
getParameter(pivotWidgetID ,"ConfigFile")
const pivotWidgetID = "pivot"
//เปลี่ยนชื่อคอลัมป์ "Project_Name" เป็น "ชื่อโปรเจค"
//เปลี่ยนชื่อคอลัมป์ "Project_ID" เป็น "รหัสโปรเจค"
//เปลี่ยนชื่อคอลัมป์ "Team" เป็น "ทีม"
//เปลี่ยนชื่อคอลัมป์ "Start_Date" เป็น "วันที่เริ่ม"
setParameter(pivotWidgetID ,"Label",[
{colName : "Project_Name",label : "ชื่อโปรเจค"},
{colName : "Project_ID",label : "รหัสโปรเจค"},
{colName : "Team",label : "ทีม"},
{colName : "Start_Date",label : "วันที่เริ่ม"},
])
const pivotWidgetID = "pivot"
getParameter(pivotWidgetID ,"Total")
// => [ {"measure":{"name":"Count of ลำดับรวม","id":0},"value":"155"},
// {"measure":{"name":"Count of IMO","id":0},"value":"155"} ]
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| String input type | String variable--Character vector | Select the input type |
| Sample time (sec) | -1 (inherited) or specify | Specify the sample time |
This block can be used to print data to a serial monitor.
This block serves as the ‘printf’ function in C programming. This block is for advanced users to debug code using a serial monitor. Check Modify Simulink generated C code in ESP-IDF for more information on using a serial monitor.
Previous : Mesh Receiver
Next : System Time Block
The content presented in this RapidSTM32 wiki describes our very first blockset and should be used as a concept and historical reference only. The software is no longer available.
This section explains a few frequently asked questions.
This tutorial aims at teaching beginners how to use RapidSTM32 Blockset in ONE DAY (approximately 6 hours). After completing the tutorials, you will have enough basic knowledge to use the Blockset to implement a variety of basic but useful applications such as:
Yes!! all those within 6 hours, no kidding. We are truly taking about Rapid Prototyping . That's Why our duck can peel banana skin? :)
This section shows basic common "how to" required for most RapidSTM32 projects.
This section shows some useful "how to" for advanced users.
This section provides reference information about the Blockset and its usages.
This section shows various sample projects from basic interfaces to external hardware/peripherals to a complete Automatic Control and Digital Signal Processing (DSP) design and analysis projects. These projects aims at showing the work flow and benefits of Model-based design and Rapid Prototyping at works. Before diving in these sample projects, it is recommended that you familiarize yourself with RapidSTM32 from Learn RapidSTM32 in A Day.
Sample projects are as follows.
RapidSTM32 Training
This page list available training workshop and materials. Example workshop include:
HIL Basic Concept Workshop
RapidSTM32 Community
This section shows:
RapidSTM32 Users List
Contributions from RapidSTM32 community
Download Repository
Blockset download
Demo files download
Training videos download
This project shows how to design a real-time moving object tracking algorithm in Matlab / Simulink. It also shows how to use Waijung to generate source code and run the algorithm in FiO 2 in real-time. Image data is transmitted to the host PC to visualize algorithm performance via UDP protocol.
The algorithm design is performed in two steps:
All demo files are under waijungroot\targets\stm32f4_target\stm32f4\demo\image_object_tracking_demo directory.
The first step we program FiO 2 board (STM32F417IG + external 8Mb SRAM) to acquire image data (resolution 120 x 160 pixels) and send to the host PC via LAN (UDP protocol). The following show hardware setup.
Hardware Setup
See DCMI Installation Guideline for instructions how to connect to connect to different version (1.1 and 1.2) of aMG CameraINF.
The following figure shows a Simulink model for the target. This model programs FiO 2 to acquire image data and send to the host PC via UDP protocol.
Target Model for image acquisition into Simulink in real-time.
The following figure shows Simulink model for the host PC. This model perform object tracking algorithm. In this way, it is very simple to visualize results, analyze performance, and tune the algorithm.
For background information on the algorithm visit http://aimagin.com/blog/basic-image-processing-object-tracking/
Track moving object from streaming video.
In this step, the algorithm is moved to run in the FiO 2 board. The detected target XY positions are overlayed on the image using Simulation Computer Vision System Blockset. The resulting image is transmitted to the host PC to display in real-time (around 5Hz update rate). The following summarized necessary steps to make it work in real-time (compare with an ideal algorithm design running in pure Simulation simulation on the host PC).
The following figure shows hardware setup.
Hardware Setup
The following figure shows Simulink model for the target. The moving object tracking algorithm runs in FiO 2 in real-time.
Simulink model file for FiO 2
The following figure shows the Simulink model running on the host PC. This model only receive image data and display on screen.
Simulink model file for the host PC
Release date: 23 November 2020
Release date: 4 November 2020
Release date: 6 October 2020
First release.
The objective of this documentation is to explain the code generation mechanism used by Waijung2.
This documentation assumes the reader has a basic understanding about FreeRTOS functionality. Click here to learn more about FreeRTOS types, functions, and macros.
Waijung2 block-set is designed to program an ESP32 board using FreeRTOS. The rest of this documentation will describe how Waijung2 implement the features of FreeRTOS when generating code for your model file.
In all model files where Waijung2 blocks are used the Target Setup Block should be present in order to upload the code to an ESP32. The Target Setup Block would adjust the necessary Model Configuration Parameters, acquire hardware specifications of your ESP32 development board in order to generate the SDK file and acquire necessary data to create the base task. The base task is the default FreeRTOS Task created to place the generated code. If all the blocks in the model has the sample time specified as inherited (-1), it will be executed within this task.
When a user specify a sample time to a block (other than -1), Waijung2 generate a separate task for each different sample time in a way that the block gets executed according to the specified frequency. If two blocks share the same sample time the code generated by the two blocks will be executed within the same task created for that specific sample time.
Another way to create a task is to use the xTaskCreate Block. The input to the xTaskCreate block can be of two types.When using the Function-Call Generator block the user has to specify a sample time for the block. If this sample time is used for another block in the same model, the generated code from that block and the block sequence connected to the output of xTaskCreate block will be executed in the same task. Therefore if there is a block with a blocking process (a process that is waiting for some event, such as a resource becoming available or the completion of an I/O operation), the block sequence connected to the output of the xTaskCreate block will not be executed in the specified frequency. In such case input of the xTaskCreate block should be a Timer Interrupt. This way the generated code for the two processes will be in separate tasks even though they have the same sample time. This is the guaranteed way to ensure a block sequence get executed despite blocking process of another block sequence with the same sample time.
Let's analyze the model shown below with the information above. Block sequence 1,2 and 3 sample times are determined by the sample time specified in the Constant block. In block sequence 4, xTaskCreate block takes the input drive from a Function-Call Generator block while block sequence 5 xTaskCreate block takes the input drive from a Timer Interrupt Block.
Here Waijung2 will create 4 tasks. Block sequences 1,2, and 5 will each have there own task at their designated sample times while block sequences 3,4 will be run on the same task with a sample time of 4 sec. Since block sequences 3,4 are in the same task, if the block sequence 3 has a blocking process, it could affect block sequence 4 sample time as well.
The sample times of the compatible blocks can be changed from the Sample time parameter in the block mask.
Previous : How to connect a hardware to a Wi-Fi Access Point
Next : Integrate Legacy C code to Waijung 2 using s-function builder
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| File path | Insert the file path. |
This block is used to write data to a file.
The block search for the file name in the given path. If the file name already exists, it opens that file and add the new data to the file. If the file name does not exist, it creates a new file and the data.
Previous : SD Card Write Block
Next : LEDC Block
SD Card Setup Block
SD Card Read Block
SD Card Write Block
SD Card Append Block
Demo file : esp32_sdcard_demo.slx
This demo shows how to use the SD Card Block and String Processing Block for data logging to ESP32. In this demo the data will be taken from the ADC pins (GPIO36, GPIO39) with ADC Block and saved into the adc_data.csv with 0.5S per record.
Once the sd card is inserted to the target module and executed the program, the data will be logged to the sd card. Wait about 10 seconds and remove the sd card and plug in to a Desktop or Laptop computer to view the data from adc_data.csv.
Previous : WIFI demo
Next : Camera demo: Stream video to Matlab Simulink
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Output data buffer size | 32--64--128--256--512--1024--2048--4096 | Select the output data buffer size. |
| File Path | Insert the file path. Example: /sdcard/’filename’ |
This block is used to read data from an already created file. For this block to function ‘SD Card Setup’ block should be present in the Simulink model file.
The block reads the content saved in the specified file up to the buffer size limit and output the data from the output port.
Previous : SD Card Setup Block
Next : SD Card Write Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| Chip select pin (CS) | 0 to 33 | Select pin for CS |
| Clock pin (SCLK) | 0 to 33 | Select pin for SCLK |
| Master read (MISO) | 0 to 33 | Select pin for MISO |
| Master write (MOSI) | 0 to 33 | Select pin for MOSI |
| Format if mount fail | True--False | If FAT partition cannot be mounted, and this parameter is true, create partition table and format the filesystem. |
| Base path | The block registers given FAT drive in VFS, at specified base path. | |
| Maximum number of files | maximum number of files which can be open at the same time | |
| Allocation unit size | If ‘format_if_mount_failed’ is set, and mount fails, format the card with given allocation unit size. Must be a power of 2, between sector size and 128 * sector size. For SD cards, sector size is always 512 bytes. |
This block can be used to initialize the SD card connected to ESP32 device before reading and writing files to it.
ESP-IDF uses the FatFs library to work with FAT filesystems. FatFs resides in the ‘fatfs’ component.
Previous : Wireless Communication Block (HIL)
Next : SD Card Read Block
| Configuration Parameter | Selectable Option/Value | Description |
|---|---|---|
| File path | Insert the file path. |
This block is used to write data to a file.
The block search for the file name in the given path. If the filename already exists, it deletes that file and create a new file with the same name and write the new data to that file. If the file name does not exist, it creates a new file and the data.
Previous : SD Card Read Block
Next : SD Card Append Block
Demo file : esp32_http_server_demo.slx
This demo shows how to use HTTP Server Setup Block, HTTP GET Handler Block and HTTP POST Handler Block by using the custom html web pages. Addition to this blocks, the WiFi Block is used to initialize the wifi in AP mode to access the http server and SD Card Setup Block is used to initialize the SD card to serve the files (.html, ,css and .png).
Note : First copy the source_files.7z and extract the files to the SD card and insert in to the ESP32 module.
Once the IP address is accessed using the web browser, the web page is as below
Model file : esp32_http_server_demo.slx
Source files : source_files.7z
Previous : System Time demo
Next : Line chart widget with ADC values
This document highlight the how to simulate LED using Simulink.
Step 01
Open Matlab. Change the current folder to the directory where you want to create the model. Click Simulink.
Step 02
Click Blank Model. Save the new model in any name you want without space to avoid any errors as '******.slx'
Pulse Generator is used to generate a pulse which will be displayed in scope. These blocks are connected to send the signal. Connect the diagram as shown below,
once connected edit the parameters as follows,
Lamp indicator is used from SImulink blockeset library under dashboard section. The signal sent between the two blocks is linked to the lamp as shown in the below picture. For more details about Building, Simulating and connecting a Simple Simulink Model
Add the state as shown in the picture, additional state can be added by clicking on the + button in Block Parameters: Lamp. The color can be adjusted by simply double clicking the color.
Step 05
Now go to Simulation Tab on the left top corner in the window, then adjust the stop time = inf so that it keep on blinking until the stopped button is pressed. Finally press the play button .
The function of this model is to blink led at 1 Hz frequency. The above model is simulated using Simulink blockset and the pulse generator is used to generate an frequency of 1 Hz. That scopes provide methods for displaying simulation data. In this example the pulse is displayed in the scope as shown below,
This shows the two blinking colors blink at 1 Hz frequency.
Click to download the lamp_blink.slx model file.
Previous:Waijung 2 installation
Next:Make Simulink model work with hardware using Waijung 2
Please see attached PDF document for configuration of Display (Smartsensor_Display config.pdf)
Notes:
1. Android application needed for configuration can be downloaded in https://support.aimagin.com/projects/support/wiki/Smart_Sensor_configure_or_monitor_application
2. Follow instructions in the pdf document, and if you are having issues not being able to see the device in the connect list, please view the sensor map of the installation and disconnect turn off the device directly above the display in the sensor map (Contact Aimagin if you need any assistance in doing this step).
Attached below is the application used to configure or monitor smartsensor system.
Please note this is installer package only for android mobile phones
Aimagin Smart sensor for schools presentation v13.pdf
The smartsensor controller can be configured in 2 ways.
1. Timer control
2. Temperature control + Timer control
1. Timer control
Timer control mode can be configured when the user goes to Temperature control menu and disables/deletes all control related to the related controller UID. Thereby if temperature control for a controller is not set in the temperature control menu, the controller will only follow the timetable (set in controller menu).
2. Temperature control + Timer control
This mode can be configured when the controller UID is set in temperature control menu. It works as follows
If Sensor Temperature is less than Recovery Temperature (Tr) -----> Follow the timetable (Normal state)
If Sensor Temperature is more than High Temperature (Th) -----> Turn ON the controller (High temperature state)
If Sensor Temperature is between Tr and Th ------> No change done
Correctly setting the Th and Tr values are crucial in order for the system to work as expected.
How to determine Th and Tr values? (Please see graph below)
First monitor temperatures recorded by the sensors in normal conditions (when the controllers are working according to the timetable). Therefore if the average normal temperature is about 23℃, please set the Tr to 24℃, this will ensure that if temperature is less than 24℃ the timetable is always followed.
Next determine the desired Th value, this value should always be higher than Tr and recommended to have at least 1℃ of separation from Tr, the reason for the separation is to prevent the controller from fluctuating from Normal state and High temperature state (to prevent fluctuating ON/OFF signals sent to controller).
Please refer Flowchart below for a more detailed explanation on the control logic used.
Note: Please note software upgrade is only available via android mobile phone
Step 1:
Please download the apk file below (amg_ble_upgrade_ble4.2_v2.0.apk), this is the application used for software upgrade (works with android phones)
Please download the bin file below (if need to upgrade gateway download amg_gateway3_emacs_wifi_iap.bin).
Step 2
Please copy these files to your android mobile phone
Step 3
Please go to the location of amg_ble_upgrade_ble4.2_v2.0.apk file in your mobile phone and click on it to install the application.
Note: Please click allow as necessary, to accept all permissions if needed by the installation process
Step 4
After installed successfully, please open the application aMG BLE Upgrade,
Step 5
After the application is opened, please click on connect as shown below!f1e.PNG!
Next select the appropriate device you want to upgrade firmware (if gateway please select amg_gateway3 or if sensor please select correct sensor based on uid)
Step 6
Please confirm that you have connected to the correct device by the text shown 
Step 7
Please click on the upgrade button on the bottom right corner.
Next browse to the location of the .bin file of the device you need to upgrade and click it
Step 8
Now device will begin updating, Status will be shown as percentage,
Step 9
Note: Please note software upgrade is only available via android mobile phone
Note: Files are given below under files tab, these can be downloaded as necessary in the steps
Step 1:
Please download the apk file below (amg_ble_upgrade_ble4.2_v2.0.apk), this is the application used for software upgrade (works with android phones)
Please download the bin file below, this is the actual software file (if need to upgrade gateway, please download amg_gateway3_emacs_wifi_iap.bin).
Step 2
Please copy these files to your android mobile phone
Step 3
Please go to the location of amg_ble_upgrade_ble4.2_v2.0.apk file in your mobile phone and click on it to install the application.
Note: Please click allow as necessary, to accept all permissions if needed by the installation process
Step 4
After installed successfully, please open the application aMG BLE Upgrade,
Step 5
After the application is opened, please click on connect as shown below
Next select the appropriate device you want to upgrade firmware (if gateway please select amg_gateway3 or if sensor please select correct sensor based on uid)
Step 6
Please confirm that you have connected to the correct device by the text shown 
Step 7
Please click on the upgrade button on the bottom right corner.
Next browse to the location of the .bin file of the device you need to upgrade and click it
Step 8
Now device will begin updating, Status will be shown as percentage, please wait till it reaches 100 % (usually take 5-10 minutes)
Step 9
After it reaches 100% it will automatically disconnect.
Step 10
To verify if successful upgrade, please connect to the device again similar to Step 5 and Step 6
Now click on Check button on bottom left. The firmware version and build date will appear please check whether this is the same version as given in the description of the bin file in download section. 