I am looking for a way to transmit data when two phones are close by. This needs to be cross platform so I cannot use NFC or iBeacon. I plan on using allJoyn to send information. I would only like to send data to others that are within a few feet of me.
Is there any way that I could get an accurate reading of distance on other phones? Or can I get an accurate distance on a master device that could be placed in the room?
So the best way that I found to do this is to use the accelerometer to tell when two devices bump then I get the bluetooth signal strength of the nearest device, if that falls into a certain value then they are touching.