Getting deep into capacitive touch driver

RE: Getting deep into capacitive touch driver

bjorn-spockeli — Wed, 07 Jun 2017 12:27:57 GMT

The link in my previous comment was incorrect, I have corrected it now so that it refers to this page. Have you attached a resistor between each pad and their respective analog input pin?

RE: Getting deep into capacitive touch driver

Lola — Tue, 06 Jun 2017 14:30:09 GMT

@Bjorn Spockeli thanks, Well I got to say your touch driver costs me too much. I'v spent a very long time trying everything from sophisticated DSP to all sorts of hardware constellations, but you have a serious problem with the ADC. I found out in multiple tests, that the ADC value is NOT STABLE, it doesn't matter what is the configuration, if you put your finger on a pad, the value goes up, say to 1700 stable, and after a few seconds down to 800 stable, then right up to 1700, and back to 800, without me doing anything. This is insane, and it causing me spending too much time because of some bugs with the ADC( in which I could see other people have).

Don't know what else can I do. it's just doesn't work, values has some kind of periodic error, god knows why.

RE: Getting deep into capacitive touch driver

bjorn-spockeli — Tue, 06 Jun 2017 12:08:17 GMT

Hi Lola, you need one resistor per sonsor-pad, as shown in this figure.