RP2040-Zero

By | 2025-03-25
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RP2040-Zero is a cheap but powerful developer tiny board utilizing a dual core ARM CPU developed by the RaspberryPi team. This particular module was developed by WaveShare.

Original web page: https://www.waveshare.com/wiki/RP2040-Zero

Where to buy

(Affiliate link)

Using it in PlatformIO

We can use the raspberrypi platform with the board named pico. platformio.ini can look like this.

[env:rp2040-zero]
platform = raspberrypi
board = pico
framework = arduino
monitor_speed = 115200
upload_protocol = picotool
lib_deps =
  fastled/FastLED

Blink LED code

We have one WS2812 RGB LED attached to PIN 16, so we should utilize that for a blink example. We use the fastLED library but adafruit/Adafruit NeoPixel will work as well.

#include <Arduino.h>
#include <FastLED.h>

#define LED_PIN 16
#define NUM_LEDS 1

#define COLOR_ORDER GRB

#define BRIGHTNESS  20

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
  FastLED.clear();
  FastLED.show();
}

void loop() {
  leds[0] = CRGB::Red;
  FastLED.show();
  delay(500);

  leds[0] = CRGB::Green;
  FastLED.show();
  delay(500);

  leds[0] = CRGB::Blue;
  FastLED.show();
  delay(500);
}

Upload the code

We should use picotool upload within platformio, but it just does not work for me.

However when you plug the device with the Boot button pressed, it will be mounted as a storage device and you can upload the code by simply copying the UF2 file to this storage. (The device will detect the change, flashes it’s new code and restart into the new firmware.)

cp .pio/build/rp2040-zero/firmware.uf2 /run/media/kelemenb/RPI-RP2/

You can enter storage device mode with the following sequence: press reset – press boot – release reset – release boot.

More to go

There are more features to test

  • Fix picotool upload issue
  • Test multi-core features
  • Try USB host/device
  • Try other peripherals, like temperature sensor