You can build your own 16-knob USB MIDI CC controller! Music software is great, but don't you miss having real knobs to turn? Harness the massive amounts of Grand Central M4 Express I/O by using CircuitPython to create a MIDI controller of your dreams to dial in sequencer values, DJ software mixes and effects, and any other value you like in your DAW, synthesizer, sequencer, or DJ tools!
The Grand Central can send USB MIDI messages, such as Note On and Note Off, as well as CC (continuous controller) numbers and values. This means you can adjust virtual knobs in your music software using real, physical knobs!
In this guide, we'll wire up 16 potentiometers and program the Grand Central MIDI Controller to do your knobby bidding!
For the MEGA proto shield version, I used some vertical PC mount 9mm 100k linear pots with 6mm knobless shafts. You can them here.
One note, I cut off their mounting tabs for the tight fit.