Has anyone tried this? Anyone have code or links to projects?
It should, in theory, be quite simple. The radios don't know whether there is one other radio listening, two other radios listening, 1000 other radios listening, or no other radios listening, when they transmit.
As long as each transmission identifies who sent it, and who it is for, the data can be broadcast to every receiver. It is up to the receiver to ignore data not meant for it.
"Tom says: Joe turn lED 3 on"
"Joe says: Tom, I can't"
Bob doesn't care what Tom and Joe are talking about.