I'm creating my own sort of one wire protocol (to drive a attiny10):
when I drive the line low for a moment the other side starts reading pulses.
So far so good. But I detect that:
if I do a digitalWrite(line, HIGH); (e.g. on D12 or D13), the other side starts to respond.
it should only respond to a digitalWrite(line, LOW);
To confirm this issue I also tried it with:
PORTB &= ~1<<PINB5;
PORTB |= 1<<PINB5;
That gives exactly the expected behavior.
It seems that digitalWrite(x, HIGH) does more than PORTB &= (1 << PINB4);
That is very interesting isn't it?!