Troubleshooting

Something is not working as expected? Not to worry, that is a normal part of building things. Here are some of the most common problems and things you can try to address them:

I saved my code but nothing happens

Check the file name. Your program has to be saved as code.py on the CIRCUITPY drive. CircuitPython also accepts main.py, but everything in this workshop uses code.py. A file with any other name is simply stored on the drive and never runs.

Restart the program. In the serial monitor, press:

Ctrl + C to stop the running program
Ctrl + D to restart it

Unplug and plug the board back in. Restarting with Ctrl + D re-runs your code, but it does not reset the hardware. If a sensor was left in use by the previous run, it stays that way until the board loses power. This is the fix when a sensor worked once and then stopped being found.

ImportError: no module named …

Your code is asking for a library that is not on the board. Open the lib folder on your CIRCUITPY drive and check whether the file or folder named in the error is there.

If it is missing, download the Adafruit CircuitPython Library Bundle for version 10.x, find the file in it, and copy it into lib.

Not everything lives in lib. Modules like board, time, digitalio, busio and analogio are built into CircuitPython itself, so they are always available and never need copying.

How do I read an error message?

When something goes wrong, the serial monitor prints a few lines that look intimidating but are mostly helpful. Read them from the bottom up:

Traceback (most recent call last):
  File "code.py", line 14, in <module>
NameError: name 'buton' is not defined

The last line says what went wrong: buton is not a name the program knows, so it is probably a typo for button.
The line above says where: line 14 of code.py.

Two of the most common ones:

NameError - a name is misspelled, or used before it was created
IndentationError - the spaces at the start of a line do not line up

Still stuck?

Ask the AI Assistant and paste the exact error message, or ask your workshop instructors.