**Description :**

I'm trying to find a way to calculate the distance between the application, and nearby Bluetooth devices.

That, or only detect devices that are `x` meters away from the device with the application.

**Tried so far :**

I tried using the Bluetooth's signal strength, but it is not reliable, as it has so many variables other than the distance (rotation of the device, objects between the 2 devices, etc). For example, I kept an eye on a device that was still on a table, and the numbers went up by 10 mBw without neither of the devices moving.

I also thought of using GPS for distance calculation, but GPS's accuracy is vary big compared to the accuracy I'm looking for (+-1m).

I look for lowering the strength of the Bluetooth signal before searching (on newer Bluetooth versions), to find less devices within a lower range. But the people who have tried it say it is unreliable because even at the lowest energy for Bluetooth, the Bluetooth was able to find devices that are about 10m away.

**Examples around us :**

If anyone has an Apple Watch and a Mac, they'd know that it is possible to unlock your Mac by simpley being close to your Mac while wearing your Watch.

Also, car keys. When you get close enough to the car while carrying the key on you, the car is unlocked.

**Notes :**

Assume all the devices are Android devices with high their hardware. It's a special implementation, not for everyone