Serial Com between Arduinos - One not always running.

Projects General Guidance
4

CrossRoads:
On A-side:
if (Serial.available()>0){ // got some data from B to process

On B-side, send an "I'm online" message when ready receive data,
"going offline" when not.

btw got the mega screw-shields today :slight_smile:

pleasure doing business with you. they look great.