Cap-touch array

Circuitsoft

So, question/idea: Could an array of cap-touch buttons be scanned?

I would imagine a grid of wires crossing over each other, let's say 1/2/3/4/a/b/c/d for 16 (4x4) buttons.

Scan through rows 1/2/3/4 in inverted schmitt trigger (self oscillation) mode.
For each of 1/2/3/4, scan through columns a/b/c/d setting each one to be the inverse of the signal output from the row you're on. If a person's finger happens to be over the cross you're currently testing, that will reduce the frequency even more than just being on the same row.

I don't have a dev board to test this. Anyone want to try?

Circuitsoft

This would be similar to a "Projected Capacitance" touchscreen. Maybe it could even do full analog multi-touch positioning like that?