Stumbled on this awesome project that uses 2 old hard drives platters as rotary encoders / jog wheels. Obviously for the purpose of DJing! I love it when people reuse hardware that was originally intended for another purpose.
The build uses an Arduino Mega 2560 as its main processor. RGB LED’s for the VUmeters, some slider pots for fading, and some extra buttons and knobs for MIDI events. On the PC software side, the author is using mixxx for the MIDI mapping.