Goals of this project:
Create an ultra-portable MIDI drum and sample pad that was more friendly, and less overkill than the DrumFighter pad.
Design something that could be built cheaply and quickly, or as a beginner project for someone getting their feet wet.
What was learned from this project:
Beyond the most basic snare/kick/hi-hat/tom note values, there is almost no standardization with regard to what note triggers what percussion sound between MIDI synthesizers, or even different drum kits in the same synthesizer. Most of the development time on this project was spent just deciding what note makes sense where.
It was interesting to discover how little apparent note standardization exists between drum samplers, or even between kits in the same program (GarageBand is especially bad about this), with the same sounds occasionally being assigned to different note values after switching kits. It's likely that they assume access to a full piano keyboard, but this still ignores players of actual MIDI drum kits. A lot of time was spent just searching for the best note assignments for the limited number of buttons. Ultimately, I just added multiple note layouts with the ability to toggle between them. It's just frustrating that this is a lot of added complexity for seemingly no sensible purpose.
I also spent quite a bit of time testing different finger drumming layouts on this device. I personally feel that the Quest for Groove layout might be the most logical, and easy to learn, and variants of this layout with only minor changes have been standard on every drum layout I have implemented since.