Rabet
An OBD-II dongle and a crash-hardened black box connecting real-time vehicle diagnostics, collision telemetry, emergency alerts, and driving scores to a mobile app — with an insurance integration that never shipped.
Two devices,
pulled apart.
Rotate the dongle and the black box on the canvas below. The dongle's shell is translucent, so its board and status LEDs show through the plastic — strip either device to a wireframe, or explode the assembly to see what every layer is for.
- Connector shell
- 16-pin OBD array
- Main housing
- Main PCB
- Interface MCU
- BLE radio
- Status LEDs
Illustrative 3D models of the two Rabet prototypes, drawn after the ELM327-class adapter and its companion recorder. The dongle listens to the CAN bus and bridges to the phone; the black box keeps its own sensors, storage, and backup power for the worst day.
A car talks constantly.
Almost nobody is listening.
Rabet — Arabic for “the link” — is an OBD-II hardware and software module built as a startup venture on the InnovEgypt track (ITIDA / TIEC, 2025). A dongle in the diagnostics port streams what the car already knows; a crash-hardened black box freezes what happens when physics takes over. Health checks, decoded warnings, driving scores, and an emergency alert chain — feeding a B2B insurance model that never quite crossed the finish line.
- Devices in the kit
- 02
- Live signals polled
- 12+
- Score dimensions
- 04
Two devices. One link.
Rabet splits the problem in two. The dongle answers “how is the car?” — it plugs into the standard OBD-II diagnostics port, polls the CAN bus, and bridges everything to the phone over Bluetooth Low Energy. The black box answers “what just happened?” — a separate event data recorder with its own inertial sensors, GPS, storage, and backup power, designed to survive the collision it records.
The listener.
CAN bus → BLE → phone
- Plugs into the J1962 diagnostics port and speaks OBD-II over the CAN bus.
- Polls live PIDs: engine speed, vehicle speed, coolant temperature, battery voltage, fuel trims, throttle position, engine load.
- Reads and clears diagnostic trouble codes, pushing decoded faults to the app as plain-language warnings.
- Lives in the port. The car never notices it; the driver never waits for it.
The witness.
IMU · GPS · camera · flash
- A 6-axis inertial unit samples acceleration and rotation continuously into a ring buffer.
- On a sustained g-spike, the pre-impact window is frozen and write-protected: velocity vectors, heading, position, and active trouble codes.
- A dashcam feed runs continuously, with event-triggered snapshot isolation around erratic driving or telemetry anomalies.
- Backup power keeps the recorder writing if the collision severs the vehicle’s own supply.
Why two devices at all?
A dongle alone dies with the harness it draws power from. A recorder alone can’t ask the car how it feels. Splitting the roles keeps each device simple, cheap to replace, and honest about its failure mode: if the crash kills the port, the black box is still writing; if the black box is offline, the dongle still reports health on every trip.
Health checks, before the light comes on.
The check-engine light is the car’s last word. Rabet listens for the whole sentence: while the driver sees a dashboard, the app sees the live parameter IDs (PIDs) behind it, polled trip after trip, with every reading kept in the context of the ones before it.
- Battery voltage
- Sag below 12.4 V while running, or a weakening crank signature across trips.
- “Battery is fading — test it before the summer heat does.”
- Coolant temperature
- Sustained readings above 105 °C, or a climb rate that outpaces the thermostat curve.
- “Running hot — check coolant level and radiator fans.”
- Fuel trims
- Long-term trim drifting beyond ±10 % — the engine compensating for something.
- “Mixture drifting — possible vacuum leak or a tired sensor.”
- Pending trouble codes
- Manufacturer pending DTCs surface here before the MIL ever lights.
- Decoded to plain language, with severity and whether it’s safe to drive.
Three states, no false alarms.
Every signal folds into a traffic-light verdict: OK, watch, or act. A single odd sample does nothing — rules fire on sustained readings and multi-trip trends, so a pothole or a cold morning doesn’t become a warning. The dongle also clears a fault code once it’s fixed, and the app remembers which warnings the car has already given, and how long the driver ignored them.
The fifteen seconds that matter.
Collision detection is a state machine, not a single sample. A sustained acceleration spike — well beyond any speed bump or kerb strike — combined with the gyro signature of a rollover or side impact, freezes the ring buffer and starts the emergency chain.
- DetectIMU · sustained g-spike + gyro signature
Impact is confirmed across a window of samples, not one jolt, before anything is sent.
- FreezeBlack box · write-protected event file
Pre-impact velocity vectors, g-trace, GPS trail, and active DTCs are sealed in flash, powered by the backup cell if the car’s supply is cut.
- IsolateDashcam · event-triggered snapshots
The seconds around the anomaly are quarantined from the continuous buffer, so the footage of the event can’t be overwritten.
- AlertApp → contacts · cloud → services
The phone dispatches SMS alerts to emergency contacts while the cloud feed carries location, severity, and vehicle data to the emergency-services integration.
A score the driver can argue with.
Every trip ends with a score from 0 to 100, and — more importantly — every deduction points at the exact moment that caused it. No opaque modelling: the driver can replay the trip and watch the points fall.
- Smoothness
- Harsh acceleration and braking events, measured on the IMU’s longitudinal axis. The single heaviest weight.
- Speed discipline
- Time spent above the limit for the road, scaled by how far above it.
- Cornering
- Sustained lateral g in bends — the difference between a curve and a swerve.
- Context
- Time of day and trip purpose: the same manoeuvre at 2 a.m. costs more than at 2 p.m.
Trips roll up into a driver profile, and the profile was designed to be portable: a record the driver owns, with the evidence attached, rather than a number an insurer computes behind a wall. That portability is exactly what the insurance chapter wanted to consume.
The chapter that never completed.
The business model bundled Rabet’s telemetry cloud with insurance products: usage-based pricing from driving scores, claims triage from black-box evidence, and dashcam snapshots to cut fraud and reconstruction time. Insurers were interested. Conversations happened. The integration never completed.
With hindsight, the reasons were structural. Actuarial teams wanted fleet-scale data before underwriting anything; the pilot had cars, not fleets. Integration roadmaps on the insurer side were heavier than either party had budgeted. And the model had a cold start: without a discount, no driver adopts the device; without drivers, there is nothing to underwrite.
Small kit. Clear responsibilities.
- Dongle
- ELM327-class OBD-II interface over CAN, bridged to Bluetooth Low Energy
- Black box
- Microcontroller, 6-axis IMU, GPS module, flash storage, camera interface, backup cell
- Firmware
- Embedded C/C++: sampling loops, a ring buffer, and the collision trigger state machine
- Mobile app
- BLE central, live health dashboard, trip history, decoded warnings, emergency contacts
- Cloud
- Trip ingestion, score computation, event and evidence storage, operations dashboard
- Recognition
- InnovEgypt startup track (ITIDA / TIEC) — Certificate of Acknowledgement C0505S25T0677
Both devices were prototyped together with the app and cloud pipeline, so a demo could run the full loop live: plug in, drive, watch the health screen, trigger a staged impact, and see the alert chain fire with the frozen evidence attached.
A telemetry pipeline is easy to demo —
and hard to underwrite.
Ninety seconds,
measured.
Speed, engine speed, and g-forces from one illustrative trip. Every harsh manoeuvre costs the score a specific number of points — and at the end, the black box earns its keep.
ignition on · dongle connected · health check OK · no stored DTCs01 / 08Ignition on
The g-trace comes from the black box IMU, not the speed chart’s derivative — impact peaks are sharper than any speed curve. Score penalties are the design weights from the case study, not a live product.
From impact
to an ambulance.
What happens in the seconds after a detected collision: evidence frozen in the car, alerts out through the phone and the cloud — and one dashed line that never carried traffic.
dongle: ELM327 ready · CAN 500 kbit/s · BLE advertising01 / 08The dongle joins the bus
The pilot’s alerts reached emergency contacts and the operations dashboard. The emergency-services API ran in demos; the dashed insurer path was designed, demoed, and never completed.
Where the
senses live.
Five subsystems, one car. Pick a layer to see where each part of the Rabet kit sits — the tour also walks itself until you take over.
Placement is illustrative: the dongle goes wherever the diagnostics port is, and the black box mounts flat against the chassis so the IMU reads the car’s motion, not a console’s rattle.