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Firmware Flashing

There are two ways to flash the firmware: Arduino IDE (simple, GUI-based) and PlatformIO (for developers, supports testing and CI).

Option A: Arduino IDE — Flash Only​

Recommended if you just want to flash the firmware onto your board. No command-line tools required.

1. Install the Arduino IDE​

Download from https://www.arduino.cc/en/software.

2. Add the Board Package​

For Feather RP2040 CAN:

  1. Open File > Preferences.
  2. In Additional Board Manager URLs, add: 
    https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
  3. Go to Tools > Board > Boards Manager, search for Raspberry PI Pico/RP2040, and install it.
  4. Select Adafruit Feather RP2040 CAN as the Board.

For Feather M4 CAN Express:

  1. In Additional Board Manager URLs, add: 
    https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
  2. Install Adafruit SAMD Boards from the Boards Manager.
  3. Select Feather M4 CAN (SAME51) as the Board.
  4. Install the Adafruit CAN library via the Library Manager.

For ESP32 boards:

  1. In Additional Board Manager URLs, add: 
    https://espressif.github.io/arduino-esp32/package_esp32_index.json
  2. Install esp32 by Espressif Systems from the Boards Manager.
  3. Select your ESP32 board (e.g. ESP32 Dev Module).

3. Install Required Libraries​

Install via Sketch > Include Library > Manage Libraries...:

  • Feather RP2040 CAN: MCP2515 by autowp
  • Feather M4 CAN Express: Adafruit CAN
  • ESP32: No additional libraries needed — the TWAI driver is built into the ESP32 Arduino core.

4. Open the Arduino Sketch​

Open the RP2040CAN folder in Arduino IDE, or open RP2040CAN/RP2040CAN.ino directly. The sketch folder name matches the primary .ino, which keeps Arduino IDE happy.

5. Select Your Board and Vehicle​

See Configuration for details on sketch_config.h.

6. Upload​

  1. Connect the board via USB.
  2. Select the correct board and port under Tools.
  3. Click Upload.
tip

For Feather boards, if the board is not detected, double-press the Reset button to enter the UF2 bootloader, then retry the upload command. For ESP32 boards, hold the BOOT button during upload if auto-reset does not work.

Option B: PlatformIO — Development, Testing & Flash​

For developers who want to run unit tests, build for multiple boards, or integrate with CI.

Prerequisites (Windows)​

ToolPurposeInstall
Python 3PlatformIO runtimewinget install Python.Python.3.14
PlatformIO CLIBuild system & test runnerpip install platformio
MinGW-w64 GCCNative test compilerwinget install BrechtSanders.WinLibs.POSIX.UCRT
tip

After installing MinGW-w64, restart your terminal so gcc and g++ are on PATH. GCC is only needed for pio test -e native (host-side unit tests) — cross-compiling to the boards uses PlatformIO's built-in ARM toolchain.

Build​

# Adafruit Feather RP2040 CAN
pio run -e feather_rp2040_can

# Adafruit Feather M4 CAN Express (ATSAME51)
pio run -e feather_m4_can

# ESP32 with TWAI (CAN) peripheral
pio run -e esp32_twai

# M5Stack Atomic CAN Base
pio run -e m5stack-atomic-can-base

Flash​

Connect the board via USB, then upload:

# Adafruit Feather RP2040 CAN
pio run -e feather_rp2040_can --target upload

# Adafruit Feather M4 CAN Express
pio run -e feather_m4_can --target upload

# ESP32
pio run -e esp32_twai --target upload

# M5Stack Atomic CAN Base
pio run -e m5stack-atomic-can-base --target upload

Run Tests​

pio test -e native
pio test -e native_bypass_tlssc_requirement
pio test -e native_log_buffer

Tests run on your host machine — no hardware required.