wvmarle:
I know that LED circuit. A simple constant-current circuit.For the testing I've set it up with simple LEDs, no transistors, just straight from the pin. The Rx needed its own resistor and is now happy. Clock is running after I got the order right, so that's progress.
Your buttons, are they active low (pull-up resistor) or active high (pull-down resistor)?
Hi. My buttons are with pull-up resistor, so I think they are active LOW.
Cheers