SparkFun Forums

[sverrirbjarna]

Im wondering if i can reduce the range of a bluetooth device or how it would be possible for me to make some kind of device that could only go a certain amount of meters from the source. And if i could set it on the go with an app or something.

[jremington]

Geofencing with radio is difficult and not accurate. The best you can do is with GPS, and for consumer grade devices you are limited to at best 2-3 meters accuracy, when outdoors with a clear view of the sky.

[stevech]

Im wondering if i can reduce the range of a bluetooth device or how it would be possible for me to make some kind of device that could only go a certain amount of meters from the source. And if i could set it on the go with an app or something.

Yes, geofencing is restricting movements to inside a polygon area.
Loss of signal at range x is easily done, but x will vary greatly, say, 10 to 1, depending the RF propagation impairments from walls, foliage, terrain, body-block, etc.
That's OK for some applications.