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Xiao RP2040

PC working environment

  • PC：MacBook Pro (13-inch, M1, 2020)
  • OS: macOS Ventura (ver 13.0.1)
  • Terminal：zsh
  • Setting : Rosetta

1. Read DATA SHEET

I learned not all contents necessary, but pin map and power information is important.
At first, browse through Seeed Studio XIAO RP2040 and RP2040 Datasheet

  • Seeed Studio XIAO RP2040 is based on the RP2040 chip and wrapped in a compact size with multiple interfaces.
  • The Language is Arduino, MicroPython and CircuitPython.

1-1) Pinout

Pinout in Seeed Studio XIAO RP2040 alt text Pinout in Fab-Xiao by Ardian Torres site.
Arduino IDE use GPIO Arduino
alt text

1-2) Features

  • Powerful MCU: Dual-core ARM Cortex M0+ processor, flexible clock running up to 133 MHz
  • Rich on-chip resources: 264KB of SRAM, and 2MB of on-board Flash memory
  • Flexible compatibility: Support Micropython/Arduino/CircuitPython
  • Easy project operation: Breadboard-friendly & SMD design, no components on the back
  • Small size: As small as a thumb(20x17.5mm) for wearable devices and small projects.
  • Multiple interfaces: 11 digital pins, 4 analog pins, 11 PWM Pins,1 I2C interface, 1 UART interface, 1 SPI interface, 1 SWD Bonding pad interface.

1-3) NOTE

  • For general I/O pins: Working voltage of MCU is 3.3V . Voltage input connected to general I/O pins may cause chip damage if it' higher than 3.3V .
  • For power supply pins: The built-in DC-DC converter circuit able to change 5V voltage into 3.3V allows to power the device with a 5V supply via VIN-PIN and 5V-PIN.
  • Please pay attention to use, do not lift the shield cover.

I tried programming with the Workflow of ADRIÁN TORRES/ Fab xiao site, the site helped me a lot!

2-1) Process

  • Open the Arduino IDE. (about Arduino IDE)
  • In Preferences, add the URL of the additional boards for Arduino-Pico that you can find here.
    alt text
  • Download Pico in the boards manager
    alt text
  • configure the Arduino IDE (In this time, choose the Seeed Studio XIAO RP2040). alt text The Seeed Studio XIAO RP2040 will appear in the COM port, in my case in "/dev/cu/usbmodem1101(Raspberry PO Pico)".
    alt text
  • In library manager, install "neopixel". (To blink LED with neopixel.)
    alt text
  • Input the quote code is as following. alt text

quote code in the blog: aloseed.com. 

#include <Adafruit_NeoPixel.h>

#define LED_POWER 11
#define LED_PIN 12

#define COLOR_REPEAT 2

Adafruit_NeoPixel pixels(1, LED_PIN);

uint8_t color = 0, count = 0;
uint32_t colors[] = {pixels.Color(255, 0, 0), pixels.Color(0, 255, 0), pixels.Color(0, 0, 255), pixels.Color(255, 255, 255)};
const uint8_t COLORS_LEN = (uint8_t)(sizeof(colors) / sizeof(colors[0]));

void setup() {
  pinMode(LED_POWER, OUTPUT);
  digitalWrite(LED_POWER, HIGH);
  pixels.begin();  // initialize the pixel
}

void loop() {
  pixels.setPixelColor(0, colors[color]);
  pixels.show();

  delay(1000);

  pixels.clear();
  pixels.show();

  delay(1000);

  count++;

  if(count >= COLOR_REPEAT) {
    count = 0;
    color++;
    if(color >= COLORS_LEN) {
      color = 0;
    }
  }
}
  • compile the program alt text
  • Load the program alt text

2-2) The result (Video):

  • Success!!
  • In this short video, you can see the operation.

3. Programming (Serial Communication) with Platform IO

Next, I tried other IDE "Platform IO".

3-1) Process

I learned the process with blog aloseed.

  • Open "Visual Studio Code"
    (About Visual Studio code.)

  • Click extension icon on left menu, and Type platformio in the search box, and install the PlatformIO IDE.
    (-This process is only the first time-) alt text

  • In PIO Home, click on "Platforms" > "Advanced Installation".
    Enter the following URL (GitHub repository) for Raspberry Pi Pico/RP2040 board (earlephilhower version) and clidk Install.
    (-This process is only the first time- ) 

https://github.com/maxgerhardt/platform-raspberrypi.git

alt text

  • When the installation is successful, the following screen appears, and click "OK" on the bottom of the screen.
    alt text

  • In Platform IO, Make new Project
    alt text

  • In the Project Wizard, enter project name and choose board.

    • Name: (Project name)
    • Board: XIAO RF2040 (Seeed)　
    • Framework: Arduino alt text

  • Open the project automatically

  • In srx > main.cpp,
    enter the programming code.
    alt text

Sample　code
The code is based on blink-echo.io by Neil, and I changed the code to "NeoPixel" and "serial communication (color change according to keyboard numbers)".

Keyboard color RGB
1 Green RGB(0,255,0)
2 Blue RGB(0,0,255)
3 Red RGB(255,0,0) 
//
// hello.RP204-XIAO.blink-echo.ino
//
// Seeed XIAO RP2040 blink and echo hello-world
//
// Neil Gershenfeld 2/12/23
//
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
//
#include <Adafruit_NeoPixel.h>
//
// globals
//
#define numpixels 1
#define pixelpower 11
#define pixelpin 12
#define bufsize 25
//
// setup
//
Adafruit_NeoPixel pixel(numpixels,pixelpin,NEO_GRB+NEO_KHZ800);
void setup() {
   Serial.begin();
   pixel.begin();
   pinMode(pixelpower,OUTPUT);
   digitalWrite(pixelpower,HIGH);
   }
//
// main loop
//
void loop() {
   if (Serial.available()) {
      char number = 0;
      Serial.println("1=Green,2=Blue,3=Red"); 
      number = Serial.read(); 
    if (number == '1'){
      pixel.setPixelColor(0,pixel.Color(0,255,0));
      pixel.show();
      delay(1000);
      pixel.setPixelColor(0,pixel.Color(0,0,0));
      pixel.show();
      pixel.show();
      }

    else if (number == '2'){      
      pixel.setPixelColor(0,pixel.Color(0,0,255));
      pixel.show();
      delay(1000);
      pixel.setPixelColor(0,pixel.Color(0,0,0));
      pixel.show();
      pixel.show();
      }

    else if (number == '3'){      
      pixel.setPixelColor(0,pixel.Color(255,0,0));
      pixel.show();
      delay(1000);
      pixel.setPixelColor(0,pixel.Color(0,0,0));
      pixel.show();
      pixel.show();
      }


     }
  }
  • build(compile) the program

  • Load the program

  • Install The Serial Monitor extension
    To get serial monitor, Install Serial monitor (by Microsoft), In extension of Visual Studio code.

alt text

3-2) HERO VIDEO / The result

Success!! In this short video, you can see the operation.

4. Personal Impressions

4-1. XIAO RP2040

  • The Seeed Studio XIAO RP2040 is powerful and consumes little power, making it ideal for making wearables and small devices.
  • As it is cheaper than other microcontroller, it is easier to use.

4-2) IDE

Compared Arduino IDE and PlatformIO, I learned below.

  • ArduinoIDE

    • for beginner, as it is easy to understand.
    • code completion is not available.
    • Slow build (compile) and load.
    • There is many code and information in lots of site.

  • Platform IO + VS code

    • Development environment that combines program editing screen, tree view, and console (log and serial monitor display) in one
    • code completion is available.
    • Have to be familiar with VSCode
    • PlatformIO is faster to build (compile) and load than the Arduino IDE

4-3) Programming code

  • As I am beginner for programming code, I use quote code to do this weeks assignment. I worked with only 1 code to edit, and found it was difficult for me. and need more study.

I work with below site. These sites helps me a lot!
- ADRIÁN TORRES/ Fab xiao
- Seeed Studio XIAO RP2040
- RP2040 chip Datasheet - PlatformIO
- blog: aloseed.com