While MIDI was the initial plan to control the two Raspberry Pis in this setup, I have decided to change.

Some research into Reaper and also the MODEP software running on the Pis both support OSC input, which allows for control similar to midi, just over a network.

My footswitch will now aim to usitlise an ethernet shield with an Arduino to send OSC messages to a small network switch, connected to both onbkard Pis.

The Arduino can receive power from one Pi, while my small usb powered switch can be powered from the other.