With a big touch surface, buttons on the side, and plenty of room inside for mods, it looked perfect to repurpose as a control surface to send a bunch of useful MIDI CCs.
Here's the finished item with some additional knobs, switches, and I/O, plus an Arduino Uno inside to handle the controls and send MIDI over USB. (Not pictured is the plastic stylus that came with the pad but I don't use -- it responds just fine to finger pressure.)
Full feature list:
- X/Y touch pad with enable/disable switches for each axis (for MIDI learn situations)
- LFO with:
- Four blendable waveforms (triangle, noise, saw up, 50% square)
- Selectable looping or one-shot mode with a reset/trigger button
- Knobs and switches for LFO output enable/disable, waveform blend, speed range, speed, and amplitude
- LED display of waveform and speed
- Five momentary buttons
- Three toggle switches
- +5v send/return loop for an expression pedal (2x RCA jacks)
- CV LFO output (rightmost RCA jack)
This pad has been sporadically useful for MIDI control of synths, DAWs, and Audiomulch -- but it's really taken on new life since I started using VCV Rack, which makes it easy to use all the pad's physical controls as virtual control voltages. Wiring up the X/Y axes to control 5-6 parameters each and sweeping a finger around the surface is godlike!
The actual CV output for the LFO is also super useful with my Neutron. I thought about adding CV outputs for the pad, but last time I cracked it open and saw the hash I'd made of the internal wiring, I reconsidered. Whatever -- I think the Uno is out of useful output pins anyway. :)
Here's the code: https://github.com/krylenko/tpMIDIpad
