Welcome
I suggest that you post your code; do not forget to use code tags as described in How to get the best out of this forum
Serial.read will return -1 (0xFF) if there is nothing to read.
A wiring diagram might also be useful.
Welcome
I suggest that you post your code; do not forget to use code tags as described in How to get the best out of this forum
Serial.read will return -1 (0xFF) if there is nothing to read.
A wiring diagram might also be useful.