Adafruit ESP32-S3 Manual page 110

2. Double-click the reset button on the board to bring up the boardnameBOOT
drive.
3. Drag the erase .uf2 file to the boardnameBOOT drive.
4. The boot LED will start flashing again, and the boardnameBOOT drive will
reappear.
5. Drag the appropriate latest release CircuitPython () .uf2 file to the
boardnameBOOT drive.
It should reboot automatically and you should see CIRCUITPY in your file explorer
again.
If you haven't already downloaded the latest release of CircuitPython for your board,
check out the installation page () YYou'll also need to load your code and reinstall
your libraries!
For SAMD21 non-Express boards that do not have a UF2
bootloader:
Any SAMD21-based microcontroller that does not have external flash available is
considered a SAMD21 non-Express board. Non-Express boards that do not have a
UF2 bootloader include the Feather M0 Basic Proto, Feather Adalogger, or the
Arduino Zero.
If you are trying to erase a non-Express board that does not have a UF2 bootloader, f
ollow these directions to reload CircuitPython using (), which will erase and
bossac
re-create CIRCUITPY.
Running Out of File Space on SAMD21 Non-
Express Boards
Any SAMD21-based microcontroller that does not have external flash available is
considered a SAMD21 non-Express board. This includes boards like the Trinket M0,
GEMMA M0, QT Py M0, and the SAMD21-based Trinkey boards.
The file system on the board is very tiny. (Smaller than an ancient floppy disk.) So, its
likely you'll run out of space but don't panic! There are a number of ways to free up
space.
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