I'm new to the electrical side of computing so bare with me. I'm working on a small arduino side project and would like to build a bump feature where any device can touch/bump another device and the two devices will become aware of each other by passing a small amount of data between each other.
Device 1 with Id 123 Device 2 with Id 456 Device 3 with Id 789
[u]Usage:[/u] Device X(Host Id, Shared Id) Device 1 (123, 456) <--> Device 2 (456, 123) | Device 3(789, null) Device 2 (456, 789) <--> Device 3(789, 456) | Device 1(123, null)
If device 1 touches device 2 then they both tell each other their ids. The same with device 2 touching device 3 or any other permutation. The caveat is that I do not want the device that is not part of the physical touch to be aware that the meeting has taken place. Nor do I want an explicit handshake protocol to commence. It should be conceivable to have 50 of these devices that have never interacted before and be able to bump them together for an accurate data swap.
[u]Protocols I've looked into:[/u] -RFID: Seems that there can only be one tag/"id" in view. Which is sort of a deal breaker. -XBEE: Seems to require a handshake as well as would broadcast to all nodes -IR: Seems like it would make the most sense but I'm a little worried about sensor alignment -NFC: I believe this has the same problem as RFID where only one tag can be in view at a time.
[u]Resulting Question:[/u] In short, is IR the best solution for this problem or is there something I have overlooked? Thanks!