Open source drag racing timing system — staging beams, Christmas tree, ET / 60ft / trap speed measurement, and race control software. Built from industrial off-the-shelf components so that any club, anywhere, can run a real drag event without a five-figure imported black box.
Status: prototype, week 1. Nothing works yet. Architecture is designed, components are on order, bench validation is next. Follow the commits.
Break the beam.
This project started the day a national drag event was cancelled mid-finals: the country's only timing system failed, and there was no second one. The timing rig turned out to be a single point of failure for an entire racing scene. Commercial systems exist — and cost like an engine build, ship for months, and are serviced an ocean away.
Beam402 is the answer: an open, reproducible, field-repairable timing system for grassroots drag racing — training days, junior events, alternative leagues, and everything the big rigs never reach.
- Timing nodes — identical boxes along the track (start, 60ft, 1/8, finish) that timestamp beam breaks with ≤1 ms resolution
- Industrial polarized retroreflective sensors — the same measurement architecture reference systems use, not hobby IR modules
- A wired RS-485 trunk with a broadcast start pulse — no clock sync, no radio jitter, verifiable with an oscilloscope
- Christmas tree module — full staging / AutoStart / pro & standard tree logic
- Race control software — classes, qualifying, ladders, time slips, and a local web scoreboard for spectators
- Per-node battery power — a cut cable loses data, never nodes
Design priorities, in order: trustworthy timing, field repairability by non-specialists, low cost, incremental deployment (start + finish + tree is already a complete working system).
| Doc | What's inside |
|---|---|
docs/architecture.md |
Full system design: sensors, timing model, bus, power, nodes, tree — including the honest list of unverified assumptions that gate the project |
docs/decisions.md |
Decision log (ADR): why wired and not wireless, why retroreflective, why DIP addressing, why no photo finish, and what evidence would change each call |
hardware/BOM.md |
Prototype bill of materials with sourcing guidance |
- Bench validation — sensor jitter rig, hardware capture jitter, start-pulse noise immunity over full-length cable (gates everything)
- Two perfboard nodes (start + finish) + tree prototype
- Parking-lot demo: staging → tree → start pulse → ET on a laptop
- Carrier PCB (KiCad) + fab-assembled batch
- Field enclosures (IP67 assemblies), full two-lane configuration
- Race control software: brackets, classes, scoreboard
- First real event
The project is young and the best time to influence it is now. Especially welcome: eyes on the architecture and decision log (tell us where we're wrong — with evidence), experience with photoelectric sensors and RS-485 in the field, and later — firmware and race-control software contributions. Open an issue; English or Russian both fine. Ground rules and how to challenge a decision: CONTRIBUTING.md.
Community chat on Telegram: t.me/beam402 — mostly Russian, English welcome. Conclusions that affect the design come back to issues; the project's record lives on GitHub.
Related projects worth knowing: MajicDesigns/DragLights (tree lamp logic this project builds on) and RotorHazard (the FPV drone timing project whose open-community architecture is a reference for ours).
Code: MIT. Hardware design files: CERN-OHL (added with the first PCB commit).
The Beam402 name and logo identify builds verified by the project — the design is free to use, the name is not a free-for-all. A self-built system is the builder's responsibility; a verification checklist will ship with v1.
Документация проекта ведётся на английском. Краткий обзор на русском: README.ru.md. Полевые регламенты и правила серии — на русском отдельно.