Designed for:
https://blog.prusaprinters.org/3d-print-an-oversized-media-control-volume-knob-arduino-basics/
PCB:
https://easyeda.com/R21m/knob-lt
Source code for Arduino ProMicro:
http://prusa3d.com/downloads/others/oversized_volume_knob.zip
ClickEncoder
https://github.com/0xPIT/encoder
The author hasn't provided the model origin yet.