The wiring is pretty straight-forward. A single wire goes from each button to pins 1,2,3,4 and a common ground connecting everybody.

The parts used for MIDIPedalBox:

• 1 - Adafruit Trinket M0

  • Buy from Adafruit
  • A QT Py or Seeed XIAO will work too, with minor code modifications

• 4 - effects pedal switches

  • I chose these generic momentary ones, but there are many to choose from and most all will work. Be sure to check dimensions to be sure!

or if you want push buttons instead of foot switches,

• 4 - 12 mm momentary buttons
  • I used these from All Electronics, but the equivalent are available from Amazon

If you want to add serial MIDI out, the CAD includes a hole for a panel mount MIDI jack, like this one

(Note: all Amazon links are affiliate links)