Passive radio receiver
Police body cameras, tasers and license-plate cameras broadcast Bluetooth and Wi-Fi identifiers so their own docks can find them. They never stop broadcasting. BeaconScout receives those advertisements and tells you what is near you.
Read this before you buy. BeaconScout gives you a distance, never a direction — one antenna cannot resolve a bearing. It cannot see a device that is switched off, and an empty screen means nothing matched was transmitting, not that nothing is there.
How it works
Nothing is uploaded, no account is created, and the app has no code path that sends your location anywhere.
The phone scans Bluetooth advertisements and Wi-Fi beacons in short duty cycles. The companion adds an external antenna and a faster Wi-Fi sweep, and keeps scanning with your screen off.
Each hit is scored against vendor identifiers — company IDs, service UUIDs, fixed address prefixes and payload tags. Independent evidence is fused, so two weak hints do not become one confident answer.
A live list with tier and estimated distance, a proximity radar, and a map that plots known fixed cameras by their true bearing. Sessions export as JSON you own.
What it sees — and what it doesn't
These are the identifiers the hardware actually transmits, and the limits that come with receiving them.
| Device | What it broadcasts | BeaconScout |
|---|---|---|
| Axon body cameras Body 3 / Body 4 |
Bluetooth address in Axon's fixed prefix, company ID 0x034D,
services 0xFC81/0xFE6B/0xFE6C,
BWCDEVICE payload tag |
Detected — typically strong confidence at 10–100 m |
| Axon tasers T7 / T10 |
Same vendor identifiers; the flaw is in hardware and cannot be patched | Detected — flagged separately from body cameras |
| Flock Safety cameras ALPR + accessories |
Wi-Fi SSIDs starting Flock-, Bluetooth names
FS Ext Battery / Penguin- / FS-,
company ID 0x09C8 |
Detected — Wi-Fi sweep on the companion reaches further than a phone |
| Flock Raven acoustic sensor |
Service UUIDs in the 0x3100–0x3500 block |
Detected |
| Anything switched off | Nothing | Not detectable. By anyone. |
| Direction to a source | — | Not available. One omni antenna, no bearing. Rings, not dots. |
What the range numbers mean. A phone hears roughly 10–100 m. The companion with an external antenna reaches several hundred metres in good conditions. Beyond about 150 m the app labels the estimate low-confidence instead of printing a number you would trust.
Pricing
The app is free on your own phone. The companion is the hardware that makes it worth carrying. The bundle is for people who want it to work out of the box.
Hardware is not shipping yet. The app is built and tested; the companion firmware compiles and the enclosure is being finalised. Reserving costs nothing and we will not take payment until a unit is ready to post.
Specifications
| Companion radio | ESP32-S3, Bluetooth LE + 2.4 GHz Wi-Fi, external antenna |
| Scan cycle | 8 s on / 2 s off (phone) · 5 s on / 1.5 s off (companion) |
| Wi-Fi sweep | every 20 s from the companion; Android throttles a phone to 4 per 2 minutes |
| Power | ~80 mA average, 10,000 mAh bank ≈ 4 days, also charges your phone |
| App requirements | Android 8.0 or newer, Bluetooth LE, location permission (Android requires it for Wi-Fi results) |
| Data | Everything stays on the device. Session files export only when you share them. No account, no analytics. |
| Detection latency | under 2 seconds from advertisement to screen |
| False positives | Every verdict shows the rules that fired and their weights. Weak hits are hidden by default. |
Questions
No, and nothing in this class can. A single omni-directional antenna measures signal strength, not angle. The radar shows distance; the map shows known fixed cameras by true bearing because those have known coordinates. Anything claiming otherwise is either using multiple antennas and multilateration, or guessing.
No. This is a receiver. If nothing is transmitting, there is nothing to receive. Treat an empty screen as "nothing matched was broadcasting", never as "you are not being watched".
Receiving is passive — the device transmits nothing on the frequencies it monitors and does not decode private content. It listens to advertisement frames these devices broadcast openly. Rules differ by country and by US state, and some jurisdictions restrict devices used to avoid law enforcement, so check your local law before relying on it. It is not legal advice.
Yes. The app alone uses your phone's Bluetooth and Wi-Fi radios and detects the same hardware at shorter range. The companion adds reach, screen-off operation and a faster Wi-Fi sweep.
Nothing, because we never receive it. There is no account, no analytics and no upload path in the app. Sessions are files on your device that leave only when you choose to share one.
Yes. Signature packs are JSON you can export, edit and re-import. A malformed pack is rejected with a reason rather than silently half-loaded, so the detector never runs on rules you did not intend.
Each rule carries a published weight and every verdict lists the rules that fired. A lone address-prefix match scores 45% and shows as weak. Two independent identifiers agreeing reaches the strong band. You can always open a row and see the arithmetic.