I've two can-bus shield stacked on two different arduino that receive data from two different loading cells...can I send a message (such as "CIAO") from one of theese to the other one or can-bus shields occupy all the serial communication?? How can i do??
can-bus shields occupy all the serial communication??
To answer that question you need to look at the technical spec for the shield and see what pins it requires, and also what hardware resources are needed by the software that drives it.