Question : Distance to a bluetooth device.

Is there a cheap and easy way to determine the distance to a bluetooth device?

Answer : Distance to a bluetooth device.

If you were to try to do this in a small space such as an auditorium, i would recomend using information both from the devices position in relation to 3 (or more) recievers and then also have fixed transmitters around the auditorium which you also determine thier position with the recievers.

Since you know the position of the fixed transmitters they would give you some idea of how the signal strength would vary over the area of the auditorium. In addition these fixed transmitters would appear to be moving (hopefully slowly) due to signal variation and you could remove this random variation from the position of the object that you want to calculate.

using all this information you could develop an algorthm that uses both you static referenece signals and looks for signals that are way outside of the limits. If you also know the maximum speed that you expect the moving object to travel at (ie attached to someone walking) you could use this to add some damping to the apparent movement of the device thus removing more error signal.

quite a complex senario though but you could add each sofictication in turn and see how many you need before you get a good possition.