circuitpython/ports/stm/boards/espruino_pico

Flashing the Espruino Pico

The Espruino Pico is normally updated via a bootloader activated by the Espruino web app. This approach is not practical for Circuitpython as it takes too much space from the internal filesystem - thus, you will need to follow the instructions for advanced reflashing using the built-in ROM bootloader on all STM32F4 MCUs (instructions sourced from https://www.espruino.com/Pico#advanced-reflashing)

• Short out the BOOT0/BTN solder jumper on the back of the board - you can do this by drawing over it with a pencil.
• Install ST's DFU utility on Windows, or dfu-util for Mac or Linux
  • Mac: install with Homebrew: brew install dfu-util
  • Linux: install with apt-get: sudo apt-get install dfu-util
  • Windows: download ST's application or install the Linux subsystem for Windows 10 and follow the linux instructions.
• Hold down the Pico's button while plugging it into USB (when overwriting Espruino's default firmware)
• Navigate to the same directory as your firmware.bin file for Circuitpython and run the following command: sudo dfu-util -a 0 -s 0x08000000 -D firmware.bin or use the ST utility on Windows.
• Restart the board.

To reinstall Espruino, follow the same steps with the latest Espruino Pico binary from espruino.com/binaries. This will reinstall the usual Espruino bootloader. You must un-short the BOOT0/BTN jumper to re-use the original Espruino Bootloader again. If you used a Pencil mark then you may need to use cleaning fluid and a small brush to totally clear out the graphite.