I got some TTP223 to be able to trigger some inputs from an Arduino Nano thru a plastic cover without drilling anything (and hiding the buttons was cool so no one knows that there is functionality hidden).
The thing is that the sensors work fine but they get activate with anything, plastic, wood, me ... is that normal? I understood that they measured the capacitance generated with humans, not with everything.
Is there anything I can do to be able to mount these TTP223s behind something? Otherwise they could be a bit useless.
Am I missing something?