I posted something that lead to this a while ago which you can read here if you'd like, where I ultimately decided that the MPR121 breakout board is my best bet, but now I'm focusing on... how the heck am I going to get at least 48 inputs from the 12 it provides? Here are some of my ideas:
1) Is multiplexing the electrodes possible? Like an example would be to attach 4 relays to each electrode, but obviously I don't want to do specifically that for several reasons... but yeah if I can multiplex them a different way that'd be great
2) Could I use multiple boards? Each board provides 12 electrodes, which, conveniently, is 48/4, so I could use 4 boards and do it that way (although that would be second choice due to software changes, hardware complications and ugliness, and expenses
3) I'm using this for a touch-sensitive piano keyboard, so would there be a way I could combine more than one key into an electrode and still get an accurate result due to the fact that the sensor is analog rather than digital? LOL could I just have the whole 32 keys be hooked to 2 electrodes??? That'd be awesome and hilarious, and the more I think about it, the more this sounds like my best option Nope, even if this worked, it would eliminate multitouch abilities. Never mind.
4) It occurs to me that quite some time ago I saw someone use a strip of metal as a range detector by sending an electrical impulse and measuring the time it took to get back kind of like sonar, but I can't seem to find the video anywhere and I've forgotten how he did it! But if this is an option, I might ditch the capacitive sensor altogether and do that...
Let me know if you have any experience doing these, have thoughts on how they might go, or have any other ideas for how to get this thing working; help is much appreciated! :)