And I want to be able to drum on two sides and the lid, with either hands or, say, marimba mallets… and get three different triggers via MIDI.
Okay, I can build the wooden box - or adapt one I already have… But the sensors? Conversion from sensor to MIDI? Is there something ready-DIY-ish I can use? And any thoughts about do I need to isolate the sides and lid somehow?
Bonus: The box has a hinged lid. I’d love to get the angle of the lid as a CC value!
If you are looking to get midi note on/off messages from piezos you could try something like the alesis io trig or ddrum ddti. I did a project a few years ago where I wanted to get isolated drum trigs from acoustic drums without bleed in order to control events in max/msp and the alesis box worked great. I didn’t get to develop the project further because the suitcase with all the gear for the project was stolen the day after the first performance. Looks like the alesis is no longer in production so the ddrum might be a better option.
Buying a small brain will save you lots of hassle. You can DIY the contact mics, and plug those straight in (after some physical isolation to minimize crosstalk). Mousepads are really handy for this.
You can go DIY on the software/hardware side too but you’ll have to do some electronic filtering on them as piezos can produce gigantic spikes (that could potentially fry your arduino or whatever you DIY it with), not to mention false triggering etc…
It’s been a while since I look it up, but lots of guides out there.
Regarding the lid: alternatives to attaching some kind of gearing to a rotary pot include flex sensors, which basically change their resistance depending on how much they’re bending. You could affix it to the inner edges of the lid, or to the back wall and the lid, and then into some kind of analog input on your control brain (microcontroller or similar). Mapping the range of possible values to a 0-127 CC is then just an exercise for the reader.