Have you ever wondered how many Bluetooth devices are floating around you? You could use one of those creepy retail store Bluetooth tracking systems, or set your smartphone to scan. Alternatively, you could use the Bluetooth Devices Visualizer from [Jeremy Geppert].
The device was inspired by [Jeremy’s] trip to Hackaday Supercon 2022. Wanting to build something with LEDs that worked in a badge-like form factor, he set out on whipping up a device to scan and display a readout of Bluetooth devices in the immediate area.
The device is based on an ESP32 microcontroller, which provides the necessary Bluetooth hardware to scan for devices. It then displays the number of devices found using an 8 x 8 array of addressable LEDs. There is also a small OLED display on board for displaying relevant details to the device’s operation. The device neatly fits on a lanyard, and is more of an art project than anything else. It’s no wardriver, and details of devices found are not logged or stored in any way when the device is switched off.
With a variety of operational modes, it’s a fun way to get an idea of just how many Bluetooth devices are really out there these days. If you’ve got your own nifty Bluetooth hacks in the works, don’t hesitate to let us know!
How does the device distinguish between bluetooth and the wifi and other cellular signals?
“Each BT device seen in a 10 second interval scan”
I assume this is done by scanning the advertising channels of BLE where every BLE-Device advertises its presence.
Also, as he talks about Air-Tags (” Phone, smartwatch, Air-tag, laptop, Air-pods, etc. “) which ONYL advertise and you cannot connect to them in a classical sense, i would highly go with the route
— He scans for BLE-Devices advertising their presence in the Advertising channels 37 (2402MHz), 38 (2426MHz) and 29 (2480MHz).