Post
by Siriushardware » Mon Aug 20, 2018 6:19 pm
In answer to your question, and somewhat to my surprise, I find this works the same way for me as it does for you, that is, I have to provide a resistance path to 0V to get the image to change. If I dampen my thumbs a little and press them to pin0 and GND respectively, then the image changes.
As far as I know the touch pins have a very high value, weak pull up on them - I think it's meant to be that just touching the pin will make it wiggle high and low in sympathy with the mains hum your body is picking up from the surrounding mains wiring, and this will be detected as 'touched', but it does not seem to work that way.