GitHub - SrMorrris/Arduino-USB-Midi-Pedalboard: How to build a USB or Bluetooth Midi Pedal board device for use it with DAW´s or plugins like amplitube, guitar rig etc..
Proto Pedal Example: Programmable Digital Pedal - SparkFun Learn
Write-Up: Adding MIDI Control to a Guitar Effects Pedal - Audio - Arduino Forum
Stomping On Microcontrollers: Arduino Mega Guitar Effects Pedal | Hackaday