The QTPy-knob Is a Simple Media Dial for Your PC
Encoder fits directly into an Adafruit QT Py board, creating an ultra-simple rotary input.
A standard keyboard/mouse setup works well enough for most tasks, but there may come a point where you really want your own custom input device for scrolling, hotkeys, or other custom purposes. For this, you can buy a macro keypad or scrolling ring of some sort, or build your own, which would normally seem much more complicated.
Having created my own, I can attest to this being a manageable, but non-trivial hardware adventure, involving a bit of soldering and snaking wires. Todbot, however, was able to make his own USB media controller using no extra wires whatsoever. In fact, the rotary encoder he used just so happens to plug right into an Adafruit QT Py SAM D21 dev board, where it can then be soldered in place. You may want to use a bit of tape to keep things from shorting, but it’s a brilliantly simple build method.
To finish off the project, todbot included a NeoPixel ring – actually adding three wires for this functionality. After experimenting with a translucent 3D-printed cylindrical housing, settled on a mostly opaque structure, with a diffuser ring in the middle to allow for a more subdued operation. Code and other design files are found in this repository, which would enable you to build your own custom user interface in record time!
The QTPy-knob is demonstrated in the video below, scrolling through text and lighting up the room in its translucent form, and configured as a volume controller in the latter iteration.