C4 Corvette Digital Dashboard

A complete digital dashboard replacement for 1984-1996 Chevrolet Corvette (C4) featuring real-time sensor monitoring, fuel consumption tracking, and multiple display styles.

🚗 C4 Corvette Digital Dashboard Creator

Hi! I'm Yahor, an automotive electronics enthusiast who built a complete digital dashboard replacement for C4 Corvettes using Arduino, ESP32, and Raspberry Pi.

What I've created:

5 retro-themed dashboard styles (Synthwave, Citroën BX, Subaru XT, Nissan 300ZX, C4 Classic)
Real-time ALDL ECU integration for accurate fuel consumption
Triple display setup with hardware-accelerated graphics
Open-source project free for personal use

Support my work:

Your coffee helps me continue developing new features, adding more vehicle compatibility, and maintaining this free project for the automotive community!

☕ Every coffee = More dashboard styles & features
📧 Contact: chupin.ye@gmail.com

Your support helps keep this project free and growing

<----------------

Or QR code:

Thank You!

Photos of different styles

You can switch between styles by pressing simultaneously AVG MPG and TRIP ODO buttons

Watch the video of Dashboard work

📁 Required Files

Core Application Files

arduino_code.cpp - Main Arduino firmware for sensor reading and data processing
arduino_combined_dashboard.py - Raspberry Pi dashboard application with all display styles
README.md - This comprehensive setup and usage guide

Symbol Images (Required for dashboard display)

coolant_temp_symbol.png - Coolant temperature gauge icon
oil_symbol.png - Oil pressure gauge icon
gas_pump_symbol.png - Fuel level gauge icon
battery_symbol.png - Battery voltage gauge icon

Documentation Files (Optional - for development reference)

ALDL_INTEGRATION_FINAL_SUCCESS.md - ALDL fuel consumption integration details
C4_DASHBOARD_COMPLETE_SETUP.md - Complete hardware setup guide
FUEL_DISPLAY_IMPROVEMENT.md - Fuel display architecture improvements
ALDL_PERFORMANCE_FIX.md - Performance optimization details
debug_timing_analysis.py - Performance analysis tool (development use)

File Structure

C4-Corvette-Dashboard/
├── arduino_code.cpp                    # Arduino firmware
├── arduino_combined_dashboard.py       # Main dashboard application
├── README.md                          # Setup guide
├── coolant_temp_symbol.png            # Required icon
├── oil_symbol.png                     # Required icon
├── gas_pump_symbol.png                # Required icon
├── battery_symbol.png                 # Required icon
├── docs/                              # Documentation (optional)
│   ├── ALDL_INTEGRATION_FINAL_SUCCESS.md
│   ├── C4_DASHBOARD_COMPLETE_SETUP.md
│   ├── FUEL_DISPLAY_IMPROVEMENT.md
│   └── ALDL_PERFORMANCE_FIX.md
└── tools/                             # Development tools (optional)
    └── debug_timing_analysis.py

Installation Priority

Essential: arduino_code.cpp, arduino_combined_dashboard.py, symbol images
Recommended: README.md for setup instructions
Optional: Documentation files for advanced configuration and troubleshooting

🚗 Project Overview

This project replaces the original C4 Corvette dashboard with a modern digital system featuring:

🎯 Key Features

Triple Display Setup: Speedometer, Tachometer, and DSI gauges
5 Display Styles: Synthwave, Citroën BX, Subaru XT, Nissan 300ZX, and C4 Classic
Real-time ALDL Integration: Dedicated ESP32 board for ECU fuel consumption data
Comprehensive Sensor Monitoring: Speed, RPM, fuel, oil, coolant, battery
Advanced Fuel Calculations: Real-time MPG and GPH from ECU data with accurate display across all styles
Hardware Acceleration: 20Hz refresh rate with optimized performance
Robust Error Handling: Comprehensive safety checks and graceful degradation

🔧 Hardware Architecture

Complete system wiring diagram showing Arduino Mega, ESP32 ALDL board, Raspberry Pi, and all sensor connections

Main Arduino (Mega 2560)

Primary dashboard control and sensor reading
20Hz main loop for smooth gauge updates
Switch monitoring and user interface
Communication hub for all components

Dedicated ESP32 ALDL Board

Real-time ALDL ECU data capture from 1988 Corvette L98 TPI
Non-blocking fuel consumption calculation
Serial communication with main Arduino
Isolated processing - zero impact on dashboard performance

Raspberry Pi 4

Triple display management (1920x1080 + 800x480 + 800x480)
Advanced graphics rendering with hardware acceleration
Style switching and user interface
Data logging and persistent storage

📡 ALDL Integration Details

The system uses a dedicated ESP32 board for ALDL (Assembly Line Diagnostic Link) integration:

ESP32 ALDL Board (ESP32_ALDL_Dedicated.ino)

GPIO19: ALDL ECU data input (160 baud, 6.24ms bit timing)
GPIO17: Serial TX to Arduino (9600 baud)
Real-time ECU fuel consumption calculation in lb/hr
Proven timing method from ALDL_reading_final.cpp
Automatic fuel counter rollover handling

Communication Flow

ECU → ESP32 (ALDL capture) → Arduino (Serial) → Raspberry Pi → Dashboard

Fuel Data Processing

ECU fuel counter and fuel constant from ALDL stream
Real-time lb/hr calculation using injector flow rates
Conversion to GPH for dashboard display (lb/hr ÷ 6.0)
Instant MPG calculation using Speed ÷ Fuel Flow

🔌 Wiring Connections

📋 See the complete wiring diagram above for visual reference

ESP32 ALDL Board

ESP32 GPIO17 → Arduino Pin 19 (Serial1 RX)
ESP32 GPIO19 → ALDL wire from ECU (Pin E on diagnostic connector)
ESP32 GND    → Arduino GND (common ground essential!)
ESP32 USB    → 5V Power supply

Main Arduino Connections

Analog Inputs: Fuel (A15), Oil (A1), Coolant (A2), Oil Temp (A3), Battery (A4), Brightness (A9), Tach (A7), Speed (A8)
Digital Inputs: Various switches (Pins 4-16) with internal pull-ups
Serial Communication: ESP32 (Pin 19), Raspberry Pi (USB)

🚗 Supported Vehicles

This project replaces the traditional analog gauges with a modern digital dashboard system using Arduino Mega and Raspberry Pi. It provides real-time monitoring of all essential vehicle parameters with enhanced features like instant/average MPG calculation, fuel consumption tracking, and customizable display themes.

Key Features

Real-time sensor monitoring: Speed, RPM, fuel level, oil pressure, coolant temperature, oil temperature, battery voltage
Advanced fuel tracking: Instant MPG, Average MPG, GPH consumption with accurate display across all styles
ALDL integration: Real-time ECU data for precise fuel consumption calculations
Multiple display styles: Synthwave, Citroën BX, Subaru XT, Nissan 300ZX, Corvette C4 themes
Triple display setup: Left speedometer, center DSI gauges, right tachometer
Hardware acceleration: Optimized for smooth 20Hz refresh rate with robust error handling
Ground loop compensation: Software correction for electrical interference

🛠️ Hardware Requirements

Core Components

Raspberry Pi 4 (recommended for performance)
Arduino Mega 2560 (main sensor interface and dashboard control)
ESP32 Development Board (dedicated ALDL ECU data processing)
Triple Display Setup:
- Left: HDMI-1 (1024x768) - Speedometer
- Center: DSI-1 (800x480) - Official Pi touchscreen with gauges
- Right: HDMI-2 (1024x768) - Tachometer

Sensors and Connections

Fuel Level: Pin A15 (470Ω pull-up + 100µF filter)
Oil Pressure: Pin A1 (1kΩ pull-up)
Coolant Temperature: Pin A2 (1kΩ pull-up)
Oil Temperature: Pin A3 (1kΩ pull-up)
Battery Voltage: Pin A4 (voltage divider)
Brightness Dimmer: Pin A5 (voltage divider)
Tachometer: Pin A7 (LM2907N output)
Speedometer: Pin A8 (LM2907N output)
ESP32 Communication: Pin 19 (9600 baud serial from ESP32 ALDL board)

ESP32 ALDL Board

ESP32 Development Board (any ESP32 with GPIO17 and GPIO19)
ALDL ECU Connection: GPIO19 (direct connection to ECU diagnostic port)
Arduino Communication: GPIO17 (serial TX to Arduino Pin 19)
Power: USB 5V (separate from Arduino)
Ground: Common ground with Arduino (essential for serial communication)

Digital Switches (Internal pull-up enabled)

Average MPG Switch: Pin 15
Instant MPG Switch: Pin 5
Average Fuel Reset: Pin 4
Trip Odometer Switch: Pin 16
Fuel Range Switch: Pin 8
Trip Odometer Reset: Pin 7
Volts Switch: Pin 10
Coolant Temp Switch: Pin 11
Oil Pressure Switch: Pin 12
Oil Temp Switch: Pin 13
Metric Switch: Pin 14

📦 Software Installation

Raspberry Pi Setup

Install Raspberry Pi OS Lite (for optimal performance)

sudo apt update
sudo apt install python3-pygame python3-serial python3-pip
sudo apt install xserver-xorg-core xinit x11-xserver-utils xrandr

Configure GPU Memory in /boot/firmware/config.txt:

gpu_mem=128
dtoverlay=vc4-kms-v3d
hdmi_force_hotplug=1
hdmi_drive=2
disable_overscan=1

Setup Display Configuration:

DISPLAY=:0 xrandr --output HDMI-1 --mode 1024x768 --pos 0x0 --rotate normal
DISPLAY=:0 xrandr --output HDMI-2 --mode 1024x768 --pos 1024x0 --rotate normal  
DISPLAY=:0 xrandr --output DSI-1 --mode 800x480 --pos 2048x0 --rotate normal

Install Dashboard Files:
- Copy arduino_combined_dashboard.py to /home/pi/
- Copy symbol images (*.png) to /home/pi/
- Set up systemd service for auto-start

ESP32 ALDL Board Setup

Install ESP32 Board Support:
- Open Arduino IDE
- Go to File → Preferences
- Add to Additional Board Manager URLs: https://dl.espressif.com/dl/package_esp32_index.json
- Go to Tools → Board → Boards Manager
- Search for "ESP32" and install "ESP32 by Espressif Systems"
Upload ESP32 Code:
- Select Board: "ESP32 Dev Module" (or your specific ESP32 board)
- Select correct COM port for ESP32
- Upload ESP32_ALDL_Dedicated.ino
Verify ESP32 Operation:
- Open Serial Monitor at 115200 baud
- Should see: "ESP32 ALDL Board Starting..."
- With ALDL connected: "ALDL Fuel: X.XXX lb/hr"

ESP32 Wiring:

ESP32 GPIO17 → Arduino Pin 19
ESP32 GPIO19 → ALDL wire from ECU
ESP32 GND    → Arduino GND

Arduino Setup

Install Arduino IDE
Upload arduino_code.cpp to Arduino Mega
Verify serial connection at 115200 baud
Connect ALDL wire from ECU Pin E (19) to Arduino Pin 19

⚙️ Configuration

Ground Loop Compensation

Important: This system includes software ground loop compensation specifically calibrated for electrical interference patterns. This may not be needed for all vehicles.

To disable ground loop compensation:

const bool ENABLE_FUEL_GROUND_LOOP_COMPENSATION = false;

To enable (default):

const bool ENABLE_FUEL_GROUND_LOOP_COMPENSATION = true;

Fuel Sensor Calibration

The fuel sensor calibration is specific to the circuit design and may need adjustment for different vehicles:

Current calibration (470Ω pull-up + 100µF filter):

Full tank: ~0V
Empty tank: ~0.78V
Current example: 0.18V = 45% fuel

To recalibrate for your vehicle:

Measure actual voltages at different fuel levels
Update the voltage thresholds in fuelLevelPercent() function
Adjust ground loop compensation values if needed

Sensor Calibration

All sensors use lookup tables based on C4 Corvette specifications. For other vehicles, you may need to adjust these values:

Temperature Sensors (Coolant & Oil)

C4 Corvette specifications:

185Ω @ 210°F (hot)
3400Ω @ 68°F (room temperature)
7500Ω @ 39°F (cold)

To calibrate for your vehicle:

Measure sensor resistance at known temperatures
Update the resistance tables in coolantTemperatureFahrenheit() and oilTemperatureFahrenheit()
Adjust calibration factors if readings don't match original cluster

Example calibration adjustment:

// Temperature calibration factor based on original cluster comparison
sensorResistance = sensorResistance * 1.47;  // Adjust this multiplier

Oil Pressure Sensor

C4 Corvette specifications:

1Ω @ 0 PSI (no pressure)
43Ω @ 30 PSI (normal idle)
86Ω @ 60 PSI (driving)
120Ω @ 80 PSI (maximum)

Non-linear calibration applied:

if (pressure < 10) {
    pressure = pressure * 4.0;  // Higher correction for low pressure
} else if (pressure < 30) {
    pressure = pressure * 2.5;  // Moderate correction
} else {
    pressure = pressure * 1.5;  // Minimal correction for high pressure
}

To calibrate for your vehicle:

Compare readings with original cluster or known good gauge
Adjust the resistance table values in oilPressurePSI()
Modify the non-linear correction factors as needed

Fuel Level Sensor

Circuit-specific calibration (depends on your pull-up resistor and circuit design):

Current setup (470Ω pull-up + 100µF filter):

Full tank: ~0V (0Ω resistance)
Current example: 0.18V = 45% fuel (26Ω resistance)
Empty tank: ~0.78V (90Ω resistance)

To calibrate for different circuit or vehicle:

Measure actual voltages at known fuel levels
Update voltage thresholds in fuelLevelPercent() function:

if (voltage <= 0.05) {
    fuel_percent = 100.0;  // Full tank threshold
} else if (voltage >= 0.78) {
    fuel_percent = 0.0;    // Empty tank threshold
}

Battery Voltage

Voltage divider calibration (R1=14.7kΩ, R2=5.5kΩ):

return voltage * 3.79;  // Calibration factor

To calibrate:

Compare Arduino reading with multimeter measurement
Adjust the multiplier (3.79) to match actual battery voltage

Brightness Dimmer

Voltage range mapping (6V-14.5V input to 20-100% brightness):

float brightness = ((actualVoltage - 6.0) / (14.5 - 6.0)) * 80.0 + 20.0;

To calibrate:

Measure actual dimmer voltage range in your vehicle
Adjust the voltage range (6.0V to 14.5V) and brightness range (20% to 100%)

🔄 Sensor Smoothing System

The dashboard implements adaptive smoothing to eliminate sensor noise while maintaining responsiveness:

Smoothing Algorithm

Each sensor uses a weighted moving average with configurable parameters:

smoothed_value = (old_value * (1 - smoothing_factor)) + (new_value * smoothing_factor)

Adaptive Smoothing Parameters

Fuel Level Smoothing

const float FUEL_SMOOTHING = 0.05;      // 5% new, 95% old (heavy smoothing)
const float FUEL_DEADBAND = 0.5;        // Ignore changes < 0.5%

Adaptive behavior:

Engine running: Even heavier smoothing (0.03) to reduce electrical noise
RC filter: Hardware 100µF capacitor provides additional noise reduction

RPM Smoothing

const float RPM_FAST_SMOOTHING = 0.8;   // Fast response for large changes (>100 RPM)
const float RPM_SLOW_SMOOTHING = 0.4;   // Moderate response for medium changes
const float RPM_DEADBAND = 30;          // Ignore changes < 30 RPM

Adaptive behavior:

Large changes: Fast response for acceleration/deceleration
Small changes: Moderate smoothing to eliminate idle oscillation

Speed Smoothing

const float SPEED_FAST_SMOOTHING = 0.95; // Ultra-fast for large changes (>5 MPH)
const float SPEED_SLOW_SMOOTHING = 0.9;  // Very fast for medium changes
const float SPEED_DEADBAND = 0.5;        // Ignore changes < 0.5 MPH

Special features:

Zero speed detection: Immediate drop to 0 when stopped
Acceleration compensation: Monitors acceleration patterns (currently disabled)

Temperature Smoothing

const float TEMP_SMOOTHING = 0.15;       // 15% new, 85% old
const float TEMP_DEADBAND = 2.0;         // Ignore changes < 2°F

Handles special cases:

"LO" temperature: Immediate display for disconnected sensors
Gradual changes: Smooth response to prevent erratic readings

Oil Pressure & Voltage Smoothing

const float OIL_PRESSURE_SMOOTHING = 0.3;  // 30% new, 70% old
const float VOLTAGE_SMOOTHING = 0.2;       // 20% new, 80% old

Deadband System

Prevents unnecessary updates when sensor values fluctuate within normal noise levels:

if (abs(new_value - current_value) > DEADBAND_THRESHOLD) {
    // Apply smoothing and update display
    current_value = apply_smoothing(new_value);
} else {
    // Keep current value (no change)
}

Customizing Smoothing

To adjust smoothing for your vehicle:

Increase smoothing (more stable, slower response):

const float SENSOR_SMOOTHING = 0.1;  // 10% new, 90% old

Decrease smoothing (faster response, more noise):

const float SENSOR_SMOOTHING = 0.5;  // 50% new, 50% old

Adjust deadband (sensitivity to changes):

const float SENSOR_DEADBAND = 1.0;   // Smaller = more sensitive

Smoothing Benefits

✅ Eliminates sensor noise without losing responsiveness
✅ Adaptive behavior based on change magnitude
✅ Prevents display flicker from minor fluctuations
✅ Maintains accuracy for significant changes
✅ Configurable parameters for different vehicle characteristics

🎨 Display Styles

The dashboard supports 5 different visual themes:

Synthwave (Default) - Retro neon aesthetic
Citroën BX - Futuristic green theme
Subaru XT - Amber/orange theme
Nissan 300ZX - Turquoise theme
Corvette C4 - Classic red theme

Style switching: Hold both trip reset and average fuel reset buttons for 1 second.

Recent Improvements (January 2025)

✅ GPH Display Fix: Resolved critical fuel consumption display bug across all styles
✅ Enhanced Error Handling: Added comprehensive safety checks for sensor data
✅ Improved Stability: Fixed RPM None value crashes and visual display issues
✅ Consistent Fuel Display: All styles now accurately show GPH values (e.g., "0.8 GPH" when idling)

🔧 Troubleshooting

Common Issues

Fuel level shows incorrect readings:

Check voltage at Arduino pin A15 with multimeter
Verify ground connections between fuel sender and Arduino
Confirm 470Ω pull-up resistor value
Test with known resistor values (26Ω, 68Ω, 100Ω)

Ground loop interference:

Ensure all sensor grounds connect to Arduino GND
Avoid using chassis ground for precision measurements
Adjust ground loop compensation values if needed
Consider using shielded cables for long sensor runs

Display issues:

Check display configuration with DISPLAY=:0 xrandr
Verify X11 server is running: ps aux | grep X
Restart display setup script if screens are mirrored
Ensure GPU memory is set to 128MB

Arduino communication:

Verify serial connection: ls /dev/ttyACM*
Check baud rate (115200)
Monitor serial output for sensor data
Test individual sensor readings

Performance Optimization

For best performance:

Use Raspberry Pi OS Lite (not desktop version)
Disable unnecessary services (bluetooth, wifi-powersave)
Enable hardware acceleration (kmsdrm driver)
Use quality SD card (Class 10 or better)
Ensure adequate power supply (3A+ for Pi 4)

📊 Technical Specifications

Performance Metrics

Dashboard refresh rate: 20Hz
Serial communication: 115200 baud
Boot time: <15 seconds (optimized)
Switch response: <1 second
Memory usage: ~100MB RAM

Fuel Consumption Accuracy

ALDL integration: Real-time ECU data when available
RPM fallback: Accurate estimation based on engine load
MPG calculation: Speed ÷ Fuel Flow Rate (GPH)
Range estimation: Current fuel × Average MPG

Electrical Specifications

Operating voltage: 12V automotive
Current consumption: <500mA total
Sensor pull-up resistors: 470Ω (fuel), 1kΩ (others)
ADC resolution: 10-bit (1024 levels)
Voltage dividers: 3.79:1 (battery), 3.676:1 (dimmer)

🤝 Contributing

This project is open source and welcomes contributions:

Fork the repository
Create feature branch: git checkout -b feature/new-feature
Commit changes: git commit -am 'Add new feature'
Push to branch: git push origin feature/new-feature
Create Pull Request

Areas for Contribution

Additional display themes
Enhanced ALDL protocol support
Data logging functionality
Mobile app integration
Additional vehicle compatibility

📄 License

This project is licensed under a Personal Use License.

License Summary:

✅ FREE for personal use - Install, modify, and use in your own vehicle
✅ FREE to share - Distribute modifications for non-commercial purposes
✅ FREE to contribute - Submit improvements to the project
❌ Commercial use requires permission - Contact author for licensing

For commercial use inquiries: chupin.ye@gmail.com

See the LICENSE file for complete terms and conditions.

🙏 Acknowledgments

C4 Corvette community for technical specifications
Original dashboard design inspiration from various automotive manufacturers
Contributors to the Arduino and Raspberry Pi ecosystems
ALDL protocol documentation and reverse engineering efforts

📞 Support

For technical support and questions:

GitHub Issues: Report bugs and feature requests
Forum Discussion: Share experiences and modifications
Documentation: Refer to included markdown files for detailed setup guides

⚠️ Important Safety Notice: This system is intended for off-road and track use. Ensure all safety systems remain functional and comply with local regulations when modifying vehicle instrumentation.

Name		Name	Last commit message	Last commit date
Latest commit History 16 Commits
docs		docs
screenshots		screenshots
tools		tools
ALDL_reading_final.cpp		ALDL_reading_final.cpp
ESP32_ALDL_Dedicated.ino		ESP32_ALDL_Dedicated.ino
LICENSE		LICENSE
README.md		README.md
arduino_code.cpp		arduino_code.cpp
arduino_combined_dashboard.py		arduino_combined_dashboard.py
battery_symbol.png		battery_symbol.png
bmc_qr.jpg		bmc_qr.jpg
c4_logo.png		c4_logo.png
coolant_temp_symbol.png		coolant_temp_symbol.png
corvette_c4_dashboard.jpg		corvette_c4_dashboard.jpg
gas_pump_symbol.png		gas_pump_symbol.png
oil_symbol.png		oil_symbol.png

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C4 Corvette Digital Dashboard