I'm (also) not successful in using the gpio on armstonea9r2dl with V3.0.
What I did:
Then I read the voltage on pin 3 of the feature connector against GND with a scope and toggle the value.
The pin is always high no matter if I write 0 or 1.
This pin has a special usage for a keypad but there's no keypad connected.
What am I doing wrong?
Thanks for any hints.