What you are going to use as a controller?
Binding something as MIDI/HID/OSC is one thing, but to be useful that something should have physical controls.
X-Touch already exists as a full scale controller with Ethernet/WiFi.
And there are puc+ / MT-BT01 for BT.
Several buttons + DIY transceiver + accu + box + debugging seems like a lot just to make these buttons wireless and also way over proposed by this thread budget.
The solution I am writing about is way simpler:
* take any mouse (wired / wireless)
* explain Windows it is NOT a mouse (technically tricky, but there is "one click" utility for that)
* put csurf Reaper extension in place (that part I am writing now...)
* assign actions
* make music
