Every modern vehicle broadcasts a unique radio ID from each tire, every few seconds, whenever the wheels turn. Sentinel listens. No camera. No plate. Works at night, through fog, behind a delivery truck, and past a plate that's been covered, swapped, or caked in mud.
Passive receive-only · 315 MHz · data stays on your property
Plate readers are good at what they do, and they fail in predictable, exploitable ways. Anyone who wants to defeat one already knows how. Sentinel isn't a replacement — it's the layer that catches what the plate layer drops.
Sentinel is designed to run alongside existing cameras and access control, not to replace them. Where you already have a plate reader, the two together tell you both who was seen and who wasn't.
There is no configuration phase where you tell it what "normal" looks like. It works that out by watching.
A software-defined radio pulls the short tire-pressure bursts every passing vehicle emits — 315 MHz in North America, 433.92 MHz elsewhere — and logs the sensor ID, time, pressure and temperature to a local database. The unit never transmits.
Over the first days it builds your traffic curve — by hour, by weekday — plus your repeat visitors and their dwell patterns. Your "normal" is measured, not configured.
Today's count against a ±σ band. First-time vehicles ranked by how long they lingered. Activity inside your quiet hours. The dashboard answers "what was different today?"
Every detector below is shipping in v1 — not a roadmap. They run on-box, on your data, with no cloud round-trip.
A vehicle with repeat visits in the last two weeks and no history before that. The signature of someone looking a place over.
An unknown vehicle that keeps arriving or leaving within minutes of the same staff vehicle, across multiple days.
Any activity inside the hours you declared dead. Default 02:00–05:00, tunable per site.
Today's unique-vehicle count against the mean ±σ of the trailing 30 days. Flags the abnormal day, not the busy one.
Thirty days of traffic as a grid. The Tuesday-3am cell that shouldn't be warm is visible at a glance.
First-time vehicles seen today, ranked by dwell time. The longer an unfamiliar vehicle sat, the higher it sorts.
Tag vehicles as alert, allow, employee or note. Paste a list to bulk-import. Alerts fire on sighting.
Who comes back, how often, how long they stay, and the distribution that makes an outlier obvious.
Multi-entrance correlation — following a vehicle from one gate to another to distinguish a drive-through from a stop — activates when a second node is deployed.
Sentinel records anonymous radio identifiers from tires. It does not read plates, photograph anyone, capture audio, or touch personal data — and it has no transmitter, so it cannot be used to broadcast, spoof, or interfere.
Sensor IDs can be one-way hashed on export, so a log handed to a third party carries no reusable identifier at all.
| Capability | Sentinel |
|---|---|
| Transmits any radio signal | No |
| Reads or stores license plates | No |
| Captures images, video or audio | No |
| Collects names or personal data | No |
| Sends your data off-site | No |
| Runs entirely on your property | Yes |
| Hashes identifiers on export | Yes |
| You own the hardware outright | Yes |
Purpose-built on proven components, assembled and burned in for 24 hours before it ships. Indoor and weatherproof outdoor builds available.
| Component | Specification |
|---|---|
| Receiver | Software-defined radio, receive-only — 315 MHz (North America) or 433.92 MHz (Europe & rest of world), selected at order |
| Compute | Quad-core ARM single-board computer, ~5 W |
| Positioning | Optional u-blox GPS receiver stamps every record with a location |
| Storage | Solid-state, sized for multi-year event retention |
| Antenna | Magnetic-mount omni tuned to your band; directional available for gates and chokepoints |
| Power | Standard 5 V USB-C mains supply |
| Network | Ethernet or Wi-Fi for dashboard access only — no outbound dependency |
| Interface | Password-protected web dashboard plus JSON API on your LAN |
| Range | Typical 10–30 ft omni; substantially further with a directional antenna at a chokepoint |
Antenna placement determines results more than any other factor. Every deployment starts with a short placement conversation about your entrances, approach angles and mounting options.
No lease, no per-camera annual fee, no contract that renews itself. The hardware is yours on delivery and the data never leaves your building.
We deploy one node at your property for 30 days, send you a daily summary of what came and went, and hand you a final report with all the raw data on day 30.
Keep the node and the $995 comes off the $1,850 — a pilot that works costs you exactly what buying it would have. Send it back and you owe nothing further.
| What you decide | What you pay, in total |
|---|---|
| Try it for 30 days, send it back | $995 |
| Try it, then keep it | $1,850 |
| Skip the trial, buy outright | $1,850 |
Limited to our first three pilot sites — we want deployments we can study properly.
Start a Proof DeploymentPrices in USD, exclusive of applicable tax. Invoiced with net terms; ACH or card.
| Leased plate reader | Sentinel Unit | |
|---|---|---|
| Try it for 30 days | not offered | $995 |
| Year 1 | $2,750 – $4,400 | $1,850 |
| Through year 3 | $7,750 – $9,400 | $1,850 |
| Through year 5 | $12,750 – $14,400 | $1,850 |
| Who owns the hardware | The vendor | You do |
| Where the data lives | Vendor cloud | Your building |
Leased-reader figures reflect published 2026 market pricing for a mainstream fixed plate-reader subscription at $2,500–$3,000 per camera per year plus a one-time $250–$1,900 installation charge. Sentinel is a complementary sensor, not a plate reader; the comparison is of cost structure, not of feature parity.
Every deployment starts with antenna placement, so the first conversation is about your entrances and what you're trying to see. Fifteen minutes is usually enough.