We made Todbot's QTPy-knob: Simple USB knob w/ CircuitPython with a Adafruit QT Py, a NeoPixel Ring, a Rotary Encoder and some 3D-printed parts. It's glowy and useful!
We modified the design so it would work with the Adafruit rotary encoder that we sell. For full details and instructions, go here: ElmwoodElectronics/qtpy-knob: QT Py Media Knob using rotary encoder & neopixel ring
We printed the whole case in translucent PET-G, and it's quite glorious: