Part 1
Anatomy of a BLE Advertising Packet
Every BLE device broadcasts a small packet dozens of times per second, no pairing required. Hover or tap each field below to see what it carries and why it can identify a device type. Sample bytes shown for a fictional manufacturer, AcmeSpecs smart glasses.
Tap a field
Select any segment of the packet to learn what it does and how detection apps use it.
Part 2
Room Scanner Simulation
Drag the glasses around the room (or use arrow keys after clicking the canvas). RSSI is computed live from a log-distance path-loss model. Cross the wall to see attenuation kick in; drag past range and the scanner loses the signal.
Part 3
Why MAC Randomization Isn't Enough
Modern devices rotate their MAC address to resist tracking. Press the button to simulate a rotation and watch which fields actually change under each strategy. Amber fields persist — that persistence is the fingerprint.
Part 4
What You Can and Can't Detect
BLE scanning is a presence signal, not surveillance-camera detection. Honest limits matter.
A scanner CAN tell you
- A BLE device matching a known smart-glasses signature is advertising nearby.
- A rough proximity estimate from RSSI (near / mid / far).
- Whether the same fingerprint keeps reappearing over time.
It CANNOT tell you
- Whether the camera is recording — camera state is never broadcast over BLE advertising.
- Exact distance or direction; RSSI is noisy and reflects off walls and bodies.
- Anything if Bluetooth is off. Silence is not proof of absence.
- Zero false positives: earbuds, watches, and shared chipsets can look similar.
Part 5
Check Your Understanding
Five quick questions with instant feedback.