We could still location based stuff with other bluetooth devices and
discovering them from the phone. Not quite sure what else we could do
indoors. Set every phone as an access point (probably only 2+?) and
get signal strength? Hmm scrub that doesn't look like you set peoples
phones up as AP automatically (understandably), unless we ndk? Which
means mesh networks are out as well.
Will
If wifi strength was omni directional and dropped off reliably you
could do it with 3 (draw three circles the weaker the signal the
bigger, see where they intersect) I think. As it is not (due to walls
etc) you might be able to get a decent proximity warning by just
comparing signal strengths. E.g. if freds signal strengths are
3,5,6,9 and bobs are 3,6,7,9 they might be close, even if you don't
know where they are. It'd be worth experimenting with.
Will
Hadn't thought of that. Hmm.
It should work, although it might up the power draw a lot.
Or have a very short range? I've noticed that arduino bluetooth
devices can come in different power draws/ranges. I'm not sure of the
ranges of the ones we have.
Will
If not then the proximity stuff will have to be IR beacons, which the
gun can then relay to the phone for processing