I am studying the capacitive buttons with the Arduino Uno, but the examples I found on the internet uses 2 wires, but I know it is possible using a single wire connected to capacitive touch key, someone would have the wiring diagram and example code simple to use that key with a single wire?
The "key" only needs one wire but a capacitive sensor needs two Arduino pins. It's not possible with one.
If each key requires 2 wires, if I make a keyboard with 12 keys, I need 24 I / O ports?
I was thinking of making an array of capacitive keys, someone would have a wiring diagram?