Scanning for (specific) phone MAC address using nRF52840 Dongle

[0Khurram0]

I know this should be possible if the phone acts as a BLE advertiser.

But is there any way to scan for a (specific) phone MAC address, if the phone is not advertising BLE (i.e. with only the phones Bluetooth toggled ON)?

For example; the nRF52840 Dongle (or any other Nordic device) is used to send a request to a MAC and if there is a response we will know that the device is nearby

Is this possible? If yes, which items would need to be explored.

Otherwise, what would be the best way to determine if a specific MAC is nearby (is it a must that the phone be a BLE advertiser?)

Thank you

[ovrebekk]

Hi 

There is no way to do this, no,at least not without running an app on the phone that enables it. 

Most phones try to avoid advertising a static MAC address for privacy reasons, otherwise it is very easy for people (with good or bad intentions) to track your phone whenever it passes a certain point. 

A safer way to do this is to run an app on the phone that configures the phone to advertise a random resolvable address. 

Random resolvable addresses typically change every 15 minutes or so, avoiding the issue where people can track you over time, but still allows trusted scanner devices to identify the phone if you share the IRK with them (using the IRK you can 'resolve' a static identifier even if the advertising address keeps changing). 

Best regards
Torbjørn