Rally Telemetry

High-performance telemetry data logger for rally cars. Real-time sensor fusion, dual-core processing, web dashboard, and alerts.

Features

• 100Hz IMU sampling - 6-axis accelerometer/gyroscope
• 10Hz GPS tracking - Position, speed, altitude
• 50Hz binary logging - Compressed format with CRC32
• Real-time alerts - G-force, roll, pitch thresholds
• Web dashboard - Live visualization at 192.168.4.1
• WiFi streaming - UDP telemetry broadcast
• Automatic log rotation - 50MB chunks, circular buffer
• Dual-core RTOS - Sensors on Core 0, I/O on Core 1

Hardware

Component	Part	Interface
Microcontroller	ESP32 DevKit	-
IMU	MPU6050	I2C (GPIO 21/22)
GPS	NEO-M8N	UART2 (GPIO 16/17)
Storage	MicroSD	SPI (GPIO 5/18/19/23)
Status LED	RGB Common Cathode	GPIO 25/26/27

Quick Start

PlatformIO

# Clone and build
git clone https://github.com/Si6gma/rallyTelemetry.git
cd rallyTelemetry

# Upload firmware
pio run --target upload

# Upload dashboard files
pio run --target uploadfs

# Monitor
pio device monitor

Arduino IDE

1. Install ESP32 board support
2. Install libraries: Adafruit MPU6050, Adafruit Unified Sensor
3. Use ESP32 Sketch Data Upload plugin for dashboard files
4. Select ESP32 Dev Module, 240MHz CPU
5. Upload

Usage

1. Power on - Blue LED blinks during initialization
2. Keep still - IMU auto-calibrates
3. Wait for GPS - Green LED when ready
4. Recording starts - Triple blink pattern

Connect to WiFi: RallyTelemetry / rally2024

Open browser: http://192.168.4.1/dashboard

Serial Commands

Command	Action
r	Start recording
s	Stop recording
f	Flush SD card
c	Calibrate IMU
t	Task statistics
h	Help

API Endpoints

Endpoint	Description
GET /api/live	Real-time telemetry JSON
GET /api/files	List log files
GET /api/convert?file=X.bin	Download as CSV
GET /download?file=X.bin	Download binary

Data Format

Binary Log Structure (72 bytes)

struct TelemetryPacket {
    uint32_t magic;        // 'RALL'
    uint16_t version;
    uint16_t sequence;
    uint32_t timestamp_ms;
    
    struct {
        float accel_x, accel_y, accel_z;  // m/s^2
        float gyro_x, gyro_y, gyro_z;     // deg/s
        float temperature;                 // Celsius
    } imu;
    
    struct {
        double latitude, longitude;
        float altitude, speed_kmh, heading;
        uint8_t satellites, fix_quality, hdop;
    } gps;
    
    uint16_t crc16;
} __attribute__((packed));

CSV Export

Timestamp,AccelX,AccelY,AccelZ,GyroX,GyroY,GyroZ,TempC,Latitude,Longitude,Altitude,SpeedKmh,Heading,Satellites,FixQuality
12345,0.123,-0.456,9.81,1.2,-0.5,0.1,25.4,40.712800,-74.006000,50.0,85.5,180.0,8,1

Configuration

Edit src/core/config.h:

// Sampling rates
const uint32_t IMU_SAMPLE_RATE_HZ = 100;
const uint32_t GPS_SAMPLE_RATE_HZ = 10;
const uint32_t LOG_RATE_HZ = 50;

// Alert thresholds
const float ALERT_G_FORCE_WARN = 2.5f;
const float ALERT_G_FORCE_CRIT = 3.5f;
const float ALERT_ROLL_WARN = 25.0f;
const float ALERT_ROLL_CRIT = 35.0f;

// WiFi settings
const char* WIFI_AP_SSID = "RallyTelemetry";
const char* WIFI_AP_PASS = "rally2024";

Architecture

Core 0 (Real-time)          Core 1 (I/O)
┌─────────────────┐         ┌─────────────────┐
│ Sensor Task     │         │ Logging Task    │
│   - IMU 100Hz   │────┐    │   - SD writes   │
│   - GPS 10Hz    │    │    │   - 50Hz        │
└─────────────────┘    │    └─────────────────┘
         ↓             │             ↑
┌─────────────────┐    │    ┌─────────────────┐
│ Compute Task    │────┘    │ Telemetry Task  │
│   - Data fusion │         │   - UDP stream  │
│   - Alerts      │         │   - Web server  │
└─────────────────┘         └─────────────────┘

Project Structure

rallyTelemetry/
├── rallyTelemetry.ino           # Main firmware
├── platformio.ini               # Build config
├── data/dashboard/              # Web UI
│   ├── index.html
│   ├── main.js
│   ├── settings.js
│   └── styles.css
├── src/
│   ├── core/                    # RTOS tasks, state machine
│   ├── sensors/                 # IMU, GPS drivers
│   ├── storage/                 # Binary logger
│   ├── telemetry/               # WiFi, web server
│   ├── alerts/                  # Threshold system
│   └── utils/                   # Ring buffers
└── test/                        # Unit tests

Testing

# Run all tests
pio test

# Run specific test
pio test -f test_ring_buffer

# Upload and run tests on device
pio test --upload-port /dev/ttyUSB0

Dependencies

• Adafruit MPU6050 ^2.2.4
• Adafruit Unified Sensor ^1.1.9
• ESP32 Arduino Core (built-in)

License

MIT License - See LICENSE