Hi, i will have one main unit of Arduino and 2-3 other Arduinos as sensors.
I thinking what is simples way to two way communication between them on wire with max length of 10m. There will be almost no data between them but if it will goes it will be important ;). Sensor need to send one command when activated, and get command to light color led or not. Speed and transmission type is unimportant, just the simples way to communicate them.