Good news everyone! I'm working on a version 2.0 board that operates over i2c using the TCA8418. This will be my first project using SMD parts and so far so good.
For switches I picked the EVQ-Q2B03W. They are more pricey than your typical tactile switch but are worth the cost in my opinion. The datasheet says they require 0.5 N of force to press, are 3.1 mm tall and are rated at 2,000,000 presses. They are VERY light touch, it really doesn't require much more force than just typing on your phone screen.
Next steps will be:
- Seeing if this will work on raspberry pis without any other hardware. Note to self: checkout how the Malti project did this.
- Write an Arduino library (mostly done)
- Write a Micropython/Circuitpython library
- Look into getting them manufactured professionally. It took me about an hour to pick and place by hand and reflow.