Easiest Way: Use storage.erase_filesystem()
Starting with version 2.3.0, CircuitPython includes a built-in function to erase and reformat the filesystem. If you have an
older version of CircuitPython on your board, you can update to the newest version (https://adafru.it/Amd) to do this.
1. Connect to the CircuitPython REPL (https://adafru.it/Bec) using Mu or a terminal program.
2. Type:
CIRCUITPY will be erased and reformatted, and your board will restart. That's it!
Old Way: For the Circuit Playground Express, Feather M0 Express, and Metro M0 Express:
If you are running a version of CircuitPython before 2.3.0, and you don't want to upgrade, or you can't get to the REPL,
you can do this.
1. Download the correct erase file:
https://adafru.it/AdI
https://adafru.it/AdI
https://adafru.it/AdJ
https://adafru.it/AdJ
https://adafru.it/AdK
https://adafru.it/AdK
https://adafru.it/AYe
https://adafru.it/AYe
https://adafru.it/DjD
https://adafru.it/DjD
https://adafru.it/DBA
https://adafru.it/DBA
https://adafru.it/Eca
https://adafru.it/Eca
You WILL lose everything on the board when you complete the following steps. If possible, make a copy of
your code before continuing.