Proper sensors / hardware


I am new to sensors and hardware. Long time programmer.

basically what I am hoping is to get some insight into how I would do something that would allow me to have an array of "pads" say 6"x6" for each pad. Maybe 20 or 30 pads. And I want to detect if a pad was touched, and what pad was touched. I am not sure if capacitive touch is the way to go. Through my research it seems that would be the most likely but open to anything.

I would like the hardware in the bad to not be too expensive.

I can see how I could potentially run separate wires from main controller board to each pad individually but I have to think there is a way to connect each pad to one another in a "daisy chain" like way.

If possible I think it would be nice for the pads to know what pads are directly connected and how many hops to each. But that makes me feel like more "beefy" hardware would be required in each pad. So not required because the main controller that they talk to could be programmed to know the layout.

Would love any input or insight into how to do this. I have searched in the forum a lot and not seen anything quite like this idea.


“Proper” :o What is ‘proper’ ?

Tell us more . . .

You can get conductive foam on eBay.

Capacitive switches:

You can use an IR key pad like these if the array was small:


Sounds like the perfect job for a TTP223 capacitive sensor. One chip per pad.

Each pad needs power and ground connections (shared) and an individual signal wire. To read all the pads I'm thinking of PCF8574 or PCF8575 port extenders in combination with an Uno or Nano, or using a Mega.