Sunder is inspired by the Buchla Thunder which is a MIDI touch controller. Sunder uses 25 capacitive sensing pads to generate MIDI data. It's built on a Bela Trill Craft and a Teensy 4.0. The Teensy can be reprogramed to send different CC's and process the sensing data in different ways. The current version calculates the centroid position X, Y, spread, and overall surface area touched (sort of pressure). Becuase Sunder uses 25 individual pads it is possible to do multi-touch and gesture recognition. Although there is a limit to what can be done on the Teensy so each pad is sent out as it's own CC as well. A PCB isn't very nice to touch in general so a layer of silicone is glued to the surface. Silicone has a higher dielectric constant than air as well! Why does this matter? I tried to design the pads in a way to maximize surface area so that there would be some pre-sensing. It actually works to some extent, you can hover your hand over the entire box and begin to change values. The silicone also gives you something to push against which helps you get a better range or possibly response curve for the psuedo pressure values. I don't know that it actually helps but it seems to. The wood box it is housed in was handmade by me! I took my time making everything square, rounding corners, and sanding. It's not perfect but it works great, feels great, and has a nice weight to it. (I may have glued a weight inside it)