Bluetooth LE RSSI for proximity detection iOS

Question

I\'ll start with the question.

Is the BTLE RSSI a good way to indicate two devices proximity to each other or not? does it only work with small devices like fobs et

Answer 1

You are entirely correct about RSSI jumping wildly and randomly. You should retrieve your RSSI values every two seconds (any faster and you get a bunch of errors). Throw out the RSSI values that are more than a ~-40 decibel spike and use an aggregate of the past values before you declare your approximate range to the user.

As for your following statement, you are in luck.

If only there was a way to reduce the signal strength of the peripheral devices advertisement....

The service you are looking for is called the TX Power Service. Implementing this service on your peripheral will allow you to decrease the transmit power of the device. That way you can throttle down the range that the advertisement data is visible from. We unfortunately do not however, have access to this service on an iOS device. But if you are writing your own firmware for a BLE peripheral, this is the service you want.