Thank you to p0larpatch for writing in and sharing with us his project called "Bluewatch," which uses a Raspberry Pi to detect when new Bluetooth devices appear in your neighborhood. While Bluewatch doesn't use an SDR and only uses a standalone Raspberry Pi, it may still interest our readers. p0larpatch explains the project below:

Get alerts when new Bluetooth devices appear in your local neighbourhood.

The real strength shows up once you actually start using it: categorize the devices you already know, your own phones, your TV, the smart plugs, the neighbour's robot lawnmower, whatever's expected around you, and BlueWatch filters all of that familiar traffic out of the way.

What's left standing out is the interesting part: the moment an unrecognized device enters the radio range of whatever's running BlueWatch, it surfaces immediately instead of being buried under dozens of devices you've already triaged.

The dashboard stops being a wall of MAC addresses and turns into an actual presence radar for your surroundings. You notice the one device that doesn't belong, not the fifty that do.