race-tracker. Automatic timing for off-road races.
A UHF RFID timing system for friendly ATV, enduro and SSV races: a reader at every checkpoint, wired to a Raspberry Pi Pico 2 W, two passive tags on every vehicle and an app that turns the reads into passings, laps and a live leaderboard.
How it works.
- Two tags per vehicle.
- Passive UHF tags, no battery, in 3D-printed holders: one on the front number plate, one on the side. They cost a few euros and never run down.
- One reader at every point.
- A UHF reader on a stand, wired to a Raspberry Pi Pico 2 W. The Pico stamps every read with GPS time, writes it to a card and sends it to the server through the marshal's phone hotspot.
- Offline first.
- Every read is saved locally, with a sequence number, and uploads whenever there is signal. If the forest has no coverage, the data reaches the server at the end.
- The server and the marshal.
- Passings become laps and a live leaderboard, with a screen for the public. A lap counts only with every intermediate point and above the minimum time; anything suspicious goes to the marshal, and every correction stays in the log.
From passing to leaderboard.
The race is a 5 km loop with three checkpoints and the finish line. The start is in groups, by class; whoever completes the most laps wins, and on a tie, whoever finished their last lap earlier. The first pass through the finish after time runs out closes the rider's race.
- The passing.
- The reader sees the tag, the Pico records the exact time and place. On a side antenna, at 40 km/h, a tag stays in the read zone for over a third of a second: enough for dozens of reads.
- The lap.
- The server checks the order CP1, CP2, CP3, finish, and the minimum lap time. A lap missing an intermediate point does not count, so the course cannot be cut.
- The leaderboard.
- Laps, lap time, position in class, in real time, on the marshal's phone and on the screen at the finish.
- Marshalling.
- Accounts with roles: admin, marshal, rider. Manual entry from a phone, cancellation, time correction, all with a trace in the audit log.
Where it is now.
The timing app runs end to end with simulated readers: registration, reads, laps, live leaderboard, TV screen and the marshal's panel.
The hardware research is done: UHF RFID wins over BLE, GPS and LoRa because the tags are cheap and have no battery. A complete reading point costs, by estimate, a few hundred euros, and four points around a thousand.
The next step is the first real reader: a single reader and a set of tags, the speed test in the field with a few vehicles, then the other three points. There is no public address yet.
Have a question or a project?
Write to us at ovidiu@heylola.ro. There are two of us, so one of us will answer.