Thank you for writing this guide! This worked for me! Managed to un-brick my SAMD21. Would like to add some more notes:
- On my Windows 10 machine, dragging and dropping the “simple_daplink_xiao.uf2” file causes Windows Explorer to lock up and crash the PC if the XIAO is not unplugged.
- The DAPLink upload is correct when the XIAO flashes blue on 2 of its LEDs.
- For PlatformIO users, download OpenOCD from here if needed, then modify the .bat file to point to the tool’s folders in “username/.platformio/packages” instead of the Arduino IDE.