Usage Manual


In order to start programming your µGame, connect it to any USB port of your computer using a micro-USB cable. Unless you are running Windows 7, you won’t need any special drivers (the drivers for Windows 7 are available at Adafruit). As soon as you connect your device, you should see a new disk driver labeled “CIRCUITPY” appear. If you browse it, you will either see some demo program already there, or just an empty disk.

You can put any files on that disk, but a few of them have a special meaning. A file called will be executed every time the device is powered on or restarted. Any other .py and .mpy files that you save there will become available to be imported from and used as libraries or programs.

You will also want to save some .bmp and .wav files to be used by your game, and possibly also some text files with level definitions and the like.

Finally, you will probably find a boot_out.txt file appearing on that disk every time the device is restarted — it contains diagnostic information about the device and the firmware on it.


Please remember to always “remove” or “unmount” the filesystem after copying or editing any files before unpluggin or hard-resetting the device (the automatic soft-reset is fine). If you don’t, and a writing operation gets interrupted, you might accidentally corrupt your filesystem and have problems with the files afterwards. If that happens, see further down this page for troubleshooting options.

Writing Files

By default, the filesystem can be written to from your computer through the USB port, but is read-only for your program. In order to be able to write to the files, or create new ones, you first have to re-mount the filesystem as read-write — this has to happen before the USB connection is made, so the code that does that has to go into the special file. But since only one thing can have write access to the filesystem, that means you will no longer be able to write files through USB from your computer. Detailed explanation is available from Adafruit tutorials.

If you want to be able to save the player’s progress, you can also use a small area of non-volatile memory available for that purpose through the nvm module.


You also have access to an interactive Python console (also called REPL) over the USB connection. You can use it to experiment with Python commands and explore the device, but it’s also very useful for debugging, as you can see everything your program prints in there, and also the text of any exceptions raised. If your program doesn’t work and you don’t know why, it’s best to first check the console for any messages. This Adafruit tutorial explains how to access the console.

Other Considerations

Generally speaking, µGame is a CircuitPython device, compatible with the Adafruit M0 boards, and behaves exactly the same as those boards.



If you have uploaded your program but it’s not working, or works for some time then abruptly stops, you have probably hit an error. To see what the error is exactly, you need to access the serial console, as explained above, and then you will see what the error is and on which line of your program.

Corrupted Filesystem

It you unplug µGame from your computer while files are still being copied, it can happen that the filesystem gets corrupted. When that happens, the surest way to recover is to copy all the important files to a safe place on your computer and format the filesystem on the µGame. To make that easy, there is a special firmware that will do it for you.

First, you need to download the format.uf2 and firmware.uf2 files. Once you have them, connect your µGame to your computer, and press the reset button twice, so that it switches into the bootloader mode. A disk called TRINKETBOOT should appear, with some files on it. When it does, copy the format.uf2 file on it, and wait for the device to reset. Your flash is now formatted. Now press reset twice again, and this time copy the firmware.uf2 file onto the disk, to get back to the CircuitPython firmware. When the device resets, you should see a brand new empty CIRCUITPY disk.