This is the heart of it all, the machine that makes all the buttons and signals work together: a Rasberry Pi 3 Model B. For easy access to the pins we mounted a ModMyPi – Paddle Breakout HAT on top.
We used an old wooden box for a casing, drilled out the holes for the cables and connectors and set it to work.
Proper systematic and clear labelling is everything, especially for last minute changes to the setup. Nothing more annoying than not knowing which cable goes to what input / output – especially when working in random mode in our case.
All Buttons connect via Jack or Midi Cables to the Raspberry Pi and all the buttons have been firmly fixated into separate boxes or onto the table.