I want to make some objects that will know when they are, let's say, 3 feet(or less) from each other.
They need to also know the identification of the objects close to them.
For example. If object Ball is in presence of a Cube, they would both be 'unhappy'. But if a Ball is in the presence of another Ball. They would both be 'happy'.
Summing up...I'm looking for cheap ways to have objects: (1) know when others are around (2) know their unique ID (which would probably require some sort of broadcasting of IDs by each device)