Your Feather M4 should already come with CircuitPython but maybe there's a new version, or you overwrote your board with Arduino code! In that case, see the below for how to reinstall or update CircuitPython. Otherwise you can skip this and proceed with the build.
Install the Adafruit NeoPixel library for Circuit Python by downloading the latest bundle. Unzip the file and locate the needed libraries. Drop the libraries into a folder named "lib" on the CIRCUITPY drive.
For non-express boards like the Trinket M0 or Gemma M0, you'll need to manually install the necessary libraries from the bundle.
Required CircuitPython Libraries:
Before continuing make sure your board's lib folder or root filesystem has the neopixel.mpy file was copied over.
Copy and paste the code below into a new text document (we recommend using Mu as your editor, which is designed for CircuitPython.). Save the file and name it as main.py
Once the files has been uploaded to the drive, the board will automatically reboot and run the code.