RFID or Bluetooth detecting range?
I have a project in which I need a stationary device (A) to pair with/detect a mobile device (B) and only that device. Once detected/paired, I need device B to light up when pulled out of range from device A. I also need to be able to adjust this range in some manner. I was looking at RFID, but I am worried about interferance from other RFID tags. Not sure if bluetooth could even do what I want in the size that I need (no more than 2x2x.25 inches for either device.) ANyone have any suggestions?