OpenPonyLogger is an open-source automotive telemetry system designed for track day data logging and analysis. Built on a ESP32-S3 platform, it provides professional-grade data acquisition at a fraction of commercial system costs.
- Device should not interfere with vehicle operation
- Non-invasive OBD-II connection (read-only)
- Secure mounting to prevent projectile hazard
- Heat management in enclosed cabin environment
- Fuse protection on power input
- All data stored locally on device
- No cloud upload without user consent
- WiFi AP mode (no internet connectivity)
- User controls all data export and deletion
- Verify track rules permit data logging devices
- Ensure mounting does not obstruct driver visibility
- Secure all wiring to prevent pedal interference
- Easy removal if required by event officials
This is an open-source project. Contributions welcome:
- Hardware improvements and alternatives
- Code optimization and bug fixes
- Additional sensor support
- Post-processing tools
- Documentation improvements
- Vehicle-specific CAN definitions
For contributor workflow, build steps, and repo hygiene, see CONTRIBUTING.md.
MIT
GitHub: https://github.com/John-MustangGT/OpenPonyLogger
Project Lead: John Orthoefer
Target Vehicle: 2014 Ford Mustang GT (S197) "Ciara"
Inspiration: Carroll Shelby's "foundation first" philosophy applied to data acquisition
For detailed information about the logging system, please refer to:
- Log Format Specification - Complete logging format including block headers, session headers, NVS schema, and write/recovery semantics
- Record Schema - Canonical C struct definitions for all record types (IMU, GPS, CAN, COMPASS)
- Project Checklist - V2 prototype implementation tasks and design decisions
- Additional references in
docs/:
| PID | Description | Units | Formula |
|---|---|---|---|
| 0x0C | Engine RPM | rpm | ((A*256)+B)/4 |
| 0x0D | Vehicle Speed | km/h | A |
| 0x11 | Throttle Position | % | A*100/255 |
| 0x05 | Coolant Temperature | °C | A-40 |
| 0x0F | Intake Air Temperature | °C | A-40 |
| 0x2F | Fuel Tank Level | % | A*100/255 |
| 0x46 | Ambient Air Temperature | °C | A-40 |
Research required - community databases available through:
- FORScan software
- OpenXC Ford platform
- Mustang6G forums
- S197 tuning communities
Engine Control:
- Engine RPM, load, timing
- Fuel injection parameters
- Air/fuel ratio (if wideband equipped)
Transmission:
- Current gear
- Transmission temperature
- Torque converter lock status
ABS/Stability:
- Individual wheel speeds
- Brake pressure
- Yaw rate sensor
- Lateral acceleration sensor (if equipped)
Steering:
- Steering angle
- Steering rate
- Power steering pressure
Document Version: 1.1
Last Updated: 2026-01-15
Status: Planning Phase