This project is old, poorly written, and has long sat unmaintained.
Control a NeoPixel strand from Arduino for OctoPrint.
Install via the bundled Plugin Manager or manually through pip using this URL:
https://github.com/MattElek/OctoPrint-Arduino-NeoPixel/archive/master.zip
Note: This plugin isn't yet registered in the OctoPrint plugin manager, but it should be registered soon.
This plugin allows you to control a AdaFruit NeoPixel strand from an Arduino. For information on how to begin using AdaFruit NeoPixels, refer to this guide. Then upload this code to your Arduino. It receives all of the hexadecimal codes sent by the plugin and turns the strand that color. You're welcome to modify it or replace it all together, the plugin send codes in a format like this '''<#FFFFFF>'''
This plugin also changes the color of the strand whenever a specific OctoPrint event happens, such as a printer connect or disconnected, a print start, fail, pause, and more. You can set the NeoPixel strand to change to a color you can pick from the OctoPrint settings.