Skip to content

Week 04 Embedded Programming

a) Description of the week

  • Prof. Neil explained microcontrollers, IDEs and languages.
  • This year the sequence of learning is different from last year.

b) Assignment of the week

1 Group assignment

  • Compare the performance and development workflows for other architectures

2 individual assignment:

  • Browse through the data sheet for your microcontroller.
  • Program a microcontroller development board to interact (with local input &/or output) and communicate (remotely)
  • Extra credit: use different languages &/or development environments

1 Group assignment

c1) Result

Group assignment page

d1) Thoughts and feelings

  • It was great to see each board worked as expected.
  • Depends on IDE and program language, UI and necessary libraries are different, but basic procedure is similar.
    1. Decide IDE and programming language
    2. Edit the code
    3. Search and install necessary libraries, it depends on the language and the device.
    4. Search and install the board setting. If necessary, select serial port on the IDE.
  • Sometimes it does not go well as expected. Knowledge for debugging is quite important.
    • Check the code error
    • Check the necessary library and board setting is installed
    • Check the port selected correctly
    • Check the serial cable is working, some cables are for only power supply.
    • Check your PC setting to use the IDE and serial programming.
    • This time I did not have the case, but sometimes the board itself is broken.

2 Individual assignment

c2) Result

- Data sheet browsing

  • I browsed data sheets of;
    RP2040
    ESP32-PICO-D4
  • I also browsed overview explanation sites as follows;
    XIAO RP2040
    M5 stack ATOM Matrix
  • I learned not all contents necessary, but pin map and power information is important.
    • XIAO RP2040 rp2040datasheet2
      rp2040datasheet1
    • M5 stack ATOM Matrix
      m5atomdatasheet1
      m5atomdatasheet2
  • Regarding "pin map", the numbering should be correctly reflected in the program. And pin has character, like below 2 kinds;
    • GPIO (general purpose input/output) : Digital I/O pins
    • UART (Universal Asynchronous Receiver Transmitter): Pins for special communication protocol this is a set of RX pin and TX pin.

- Program and try different development environments

  • Development environments
    -I used "Arduino IDE" and "Platform IO IDE on VS code" as shown in group assignment

    • Programmed "XIAO RP2040" and "M5 stack ATOM Matrix" as shown in group assignment

  • Program
    For XIAO RP2040, I uploaded below code and make neopixel LED red blink. 

    #include <Adafruit_NeoPixel.h>

#define NUMPIXELS 1
#define NEO_PWR 11 //GPIO11
#define NEOPIX 12 //GPIO12

Adafruit_NeoPixel pixels(NUMPIXELS, NEOPIX, NEO_GRB + NEO_KHZ800);

void setup() { 
pixels.begin();
pinMode(NEO_PWR,OUTPUT);  digitalWrite(NEO_PWR, HIGH);
delay(200);
}

void loop() { 
pixels.setPixelColor(0, pixels.Color(255, 0, 0));  pixels.show();  delay    (200); //LED color adjusted Red only
pixels.clear();  pixels.show();  delay(200);

}
    The original code for above is in this site and changed LED color simpler. (Only red)

  • Program M5 Atom
    I also uploaded below code and show text on serial monitor by pressing the button on M5Atom. 

    #include <M5Atom.h>

void setup() {
  M5.begin();
}

void loop() {
 M5.update();
  if(M5.Btn.isPressed()){//If the button pressed,
    Serial.println("Fab lab Kitakagaya!"); // show letters "Fab lab Kitakagaya!" on serial monitor.
  }
  delay(200);
}
    To make this code, I referred this site and modified below code for M5Atom and change the text shown in the serial monitor 
    #include <M5Core2.h>

void setup() {
  M5.begin();
  M5.Lcd.println("Please pressed Button A.");
}

void loop() {
  M5.update();
  if (M5.BtnA.wasPressed()) {    //If the key is pressed. 
    M5.Lcd.println("Button is pressed.");
  } 
  delay(20);
}

f2) Thoughts and feelings

  • "Data sheet" has a lot of detailed information, but for me quite difficult. On the other hand, "Overview" site by each supplier is edited briefly and covers important points. As a beginner of microcontrollers, it is better to begin with overview information.
  • Pin allocation seems quite important for actual work.
  • In the beginning, I could not understand the difference between RP2040 and XIAO RP 2040. But by browsing suppliers documents many times finally got that RP2040 is a name of microcontroller, and XIAO RP2040 is the name of a board with RP2040. I must identify "tip" and "board".
  • This is the first time for me to use microcontrollers and program into it. It was super fun when my program worked.
  • I tried 2 development environment "Arduino IDE" and "VScode + Platform IO". The basic idea and process seems the same. But the appearance and performance are not the same. I prefer Arduino IDE in appearance, but the compile time takes longer than other one.
  • As for Platform IO, serial writing did not work. I managed to write it with alternative way.

g) References

Data sheet of RP2040
Data sheet of ESP32-PICO-D4
Overview of XIAO RP2040
Overview of M5stack ATOM Matrix
XIAO RP2040 program sample

(end of document)