question about touch sensor MPR121

Other Hardware Sensors
1

Hello
I once used a MPR121 to detect touch, and it worked fine for touch on-off detection

it is not clear to me if I can use this IC to measure how much I touch the sensor, I mean, using only 1 input of the 12 included in the IC, can I tell if my finger is just barely touching the sensor it or is totally flat over the sensor?

I know I could to that using many little sensors with the 12 inputs and checking how many of them have been touched (like on a trackpad), but I'm wondering if you can do that with only one big sensor and one input, after all I don't need to detect position but just the amount of touched surface

2

You cannot measure the touched surface with this chip but as the chip only measures the capacity of the capacitor built by your finger and the pad you should be able to detect several levels of finger proximity. Read out the low level registers of the chip and calibrate with your specific pad and you should be able to differentiate several levels. It might just work with exactly your finger but I'd say it worth a try.