Apologies for the lack of updates on this bad boy - progress is still slowly ticking away in the background!
I'm currently fixing some issues in the software at present; upgrading everything to allow the use of the AudioInjector card has broken my WiFi, unfortunately. I've slowly getting to the the bottom of it, but it has been a time consuming and frustrating affair.
I have also been doing some work on the Wah/Expression Pedal input; rather than sticking an arduino in and plugging it in I am tempted to experiment with an ESP8266 to send data wirelessly.
I already have a python script translating GPIO pin button presses into MIDI, so adding some further code in there to translate incoming data is entirely plausible.