Removes: * AUTORESET_DELAY_MS which never did anything but was introduced somehow. * CIRCUITPY_BOOT_BUTTON in all but one ESP board because they all have them. There is a default based on the strapping pins. * BOARD_USER_SAFE_MODE_ACTION because it was all the same for boards with boot buttons. Now the safe mode code manages the message.
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.
- Mac: install with Homebrew:
- 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.