PC Volume Mixer
The idea of this project is to control the volume of different software running on pc producing sound individually. So for example let's say you playing a video game while listening to music and you want to lower the music volume but keep the game volume the same.
Items needed:
Arduino Pro Micro Or Nano
Wires
Potentiometer
Micro USB to cable
3D printed files (Optional)
Screwes (optional)
Hot glue (optional)
Wiring Diagram:
After following the wiring diagram you will need to upload the sketch on the Arduino & make sure you edit the analog inputs to match how you connected them or else it will not work!!!
Then you will need to download two files and put them together ( config.yaml & deej.exe)
First, you will edit config.yaml to assign which rotary for what program to control. Then you will launch deej.exe and you are done at this point.
Example: 
Links:
Rotary Potentiometer
Pro Micro Atmega32U4
STL files
STL files 2
STL Files 3
Reference:
https://github.com/omriharel/deej/releases/tag/v0.9.10