Precision Meets Performance
The ultimate open-source vehicle performance timer. 10Hz UBX GPS & 100Hz IMU telemetry, 3D gravity leveling, wireless BLE OTA updates, and a sleek companion app.
Engineered for Accuracy
Advanced physics computations, 3D attitude alignment, and hardware integration for the ultimate run.
3D Attitude Alignment
Mount OpenDragy at any angle (0–359°) or sloped surface. Continuous 3D gravity tracking (Ax, Ay, Az) projects acceleration onto the true horizontal plane, eliminating pitch/roll slope leakage and cosine attenuation.
10Hz GPS & 100Hz IMU
Parses binary UBX-NAV-PVT packets 10 times per second directly from the u-blox M10 navigation solution, fused with 100Hz live accelerometer streaming and ESP32 hardware EMA smoothing.
Voice Callouts & Cabin Audio
Real-time spoken announcements for launch arming, milestone splits, and trap speeds. Optional cabin recording captures engine and exhaust notes synced directly to your telemetry curves.
Wireless BLE OTA Updates
Wirelessly check for, download, and flash ESP32-S3 firmware updates directly over Bluetooth Low Energy from within the companion app without opening the case or plugging in USB.
Drag, Intervals & Braking
Complete performance suite: standing drag milestones with NHRA rollout, rolling acceleration intervals, and dedicated deceleration braking tests.
Garage & Weather Sync
Manage multiple vehicles (cars & bikes) with localized profiles, and automatically log real-time ambient temperature, elevation, and relative humidity via Open-Meteo API.
Precision Telemetry & 3D Orientation
- High-Precision 10Hz UBX: Direct binary UBX-NAV-PVT packets 10 times per second straight from the u-blox internal navigation engine.
- 100Hz Real-Time IMU Telemetry: High-rate accelerometer stream mapped to G-force curves with hardware EMA filtering on the ESP32.
- Dynamic 3D Gravity Vector Projection: Continuously projects acceleration onto the true horizontal plane orthogonal to gravity, preventing cosine attenuation and slope leakage.
- Interactive 360° Pivot Preview: Top-down rotating graphical preview dialog with 0°, 90°, 180°, 270° quick presets and 1° fine slider.
- Zero-Crossing Interpolation: Interpolates launch start time down to the millisecond between stationary and moving states.
- Auto-Armed Launch: Automatically arms and triggers when exceeding 3.0 km/h to bypass GPS drift and jitter.
Analytics, Voice & Wireless Ecosystem
- Voice Announcements (TTS): Real-time spoken callouts for armed state, launch, intermediate milestones, and trap speeds.
- Cabin Audio Recording: Record exhaust audio synchronized directly with interactive speed and G-force graphs.
- Wireless BLE OTA Updates: Update ESP32-S3 microcontroller firmware wirelessly from your phone.
- Interactive Slopes & Curves: High-resolution charts showing speed curves, G-forces, elevation profiles, and NHRA slope validity.
- Garage & Fleet Management: Track independent performance metrics across all your vehicles.
- Automated Weather Logging: Automatic temperature, altitude, and humidity fetching using Open-Meteo.
- OLED Theme & Smart Wakelock: OLED-optimized dark UI that keeps your display awake during active sessions.
Track Every Milestone
From standing launches and roll racing to deceleration braking tests, OpenDragy covers every performance metric.
- Drag Mode (Standstill): 60ft to 1/2 mile with trap speeds, optional NHRA 1-ft rollout deduction, and 66ft trap speed calculations.
- Braking & Deceleration: Dedicated deceleration tests with directional speed-crossing detection (e.g. 100–0 km/h, 60–0 mph).
- Speed Intervals: Standard Metric and Imperial acceleration splits (including 0–60, 60–130, 0–100, 100–200, and rolling ranges).
- Custom Targets: Create custom distance and speed interval tests in any unit with test visibility toggles.
Open-Source Hardware
Build your own high-precision timer with off-the-shelf components. Our ESP32-S3 firmware handles high-rate binary parsing, sensor fusion, and wireless OTA updates.
Showcase
A closer look at the OpenDragy app and hardware components.
App Interface
Hardware
