How to estimate distance between two android devices? (bluetooth preferred)

Question

Target is not to have the real distance. It is something simpler.
Target is to check whether another device is very very close. True or false. Let\'s say 1

Answer 1

You are not specifying the objective for this distance detection, but if you could add some additional requirements to that (i.e phone orientation and flash light), a totally different approach could probably be used.

If both devices are oriented in a way that both cameras face each other, the flash light could be used to validate the correct phone and distance. The size of the white spot generated in the camera image decreases rapidly with distance, and a specific flash sequency could differentiate between the other phone flash light and other light sources.

This could require some tweaking to work outdoors, as for the same distance the spot size will be much smaller ...

Regards.