TrailCurrent Electric Heater Control

Firmware and hardware module for controlling an electric heater via CAN bus with OTA firmware update capability.

Hardware Overview

• Microcontroller: ESP32-C6
• Function: Electric heater control with CAN bus communication
• Key Features:
  • CAN bus communication at 500 kbps
  • Over-the-air (OTA) firmware updates via WiFi
  • RGB LED status indicator
  • DHT22 temperature/humidity monitoring
  • Custom flash partition layout with dual OTA slots

Hardware Requirements

Components

• Microcontroller: ESP32-C6-Super-Mini
• Sensors: DHT22 temperature/humidity
• Communication: CAN bus transceiver (TX: GPIO 15, RX: GPIO 14)
• Status: RGB LED on GPIO 8

KiCAD Library Dependencies

This project uses the consolidated TrailCurrentKiCADLibraries.

Setup:

# Clone the library
git clone https://github.com/trailcurrentoss/TrailCurrentKiCADLibraries.git

# Set environment variables (add to ~/.bashrc or ~/.zshrc)
export TRAILCURRENT_SYMBOL_DIR="/path/to/TrailCurrentKiCADLibraries/symbols"
export TRAILCURRENT_FOOTPRINT_DIR="/path/to/TrailCurrentKiCADLibraries/footprints"
export TRAILCURRENT_3DMODEL_DIR="/path/to/TrailCurrentKiCADLibraries/3d_models"

See KICAD_ENVIRONMENT_SETUP.md in the library repository for detailed setup instructions.

Opening the Project

1. Set up environment variables (see Library Dependencies above)
2. Open KiCAD:

   kicad EDA/TrailCurrentElectricHeaterControl/TrailCurrentElectricHeaterControl.kicad_pro

3. Verify libraries load - All symbol and footprint libraries should resolve without errors
4. View 3D models - Open PCB and press Alt+3 to view the 3D visualization

Firmware

See src/ directory for PlatformIO-based firmware.

Setup:

# Install PlatformIO (if not already installed)
pip install platformio

# Build firmware
pio run

# Upload to board (serial)
pio run -t upload

# Upload via OTA (after initial flash)
pio run -t upload --upload-port esp32c6-DEVICE_ID

Firmware Dependencies

This firmware depends on the following public libraries:

• C6SuperMiniRgbLedLibrary (v0.0.1) - RGB LED status indicator driver
• Esp32C6OtaUpdateLibrary (v0.0.1) - Over-the-air firmware update functionality
• Esp32C6TwaiTaskBasedLibrary (v0.0.3) - CAN bus communication interface
• Adafruit DHT sensor library (v1.4.6+) - Temperature and humidity sensor

All dependencies are automatically resolved by PlatformIO during the build process.

WiFi Credentials (for OTA updates):

• Copy src/Secrets.h.example to src/Secrets.h and fill in your WiFi credentials
• Never commit Secrets.h to version control (it's in .gitignore)

CAN Bus Protocol

• Receive ID 0x00: OTA update notifications - triggers firmware update when device ID matches
• CAN speed: 500 kbps

Manufacturing

• PCB Files: Ready for fabrication via standard PCB services (JLCPCB, OSH Park, etc.)
• BOM Generation: Export BOM from KiCAD schematic (Tools > Generate BOM)
• JLCPCB Assembly: See BOM_ASSEMBLY_WORKFLOW.md for detailed assembly workflow

Project Structure

├── EDA/                          # KiCAD hardware design files
│   └── TrailCurrentElectricHeaterControl/
│       ├── *.kicad_pro           # KiCAD project
│       ├── *.kicad_sch           # Schematic
│       └── *.kicad_pcb           # PCB layout
├── src/                          # Firmware source
│   ├── Main.cpp                  # Main application
│   ├── Globals.h                 # Debug macros and data structures
│   └── Secrets.h.example         # WiFi credentials template
├── platformio.ini                # Build configuration
└── partitions.csv                # ESP32 flash partition layout

License

MIT License - See LICENSE file for details.

This is open source hardware. You are free to use, modify, and distribute these designs for personal or commercial purposes.

Contributing

Improvements and contributions are welcome! Please submit issues or pull requests.

Support

For questions about:

• KiCAD setup: See KICAD_ENVIRONMENT_SETUP.md
• Assembly workflow: See BOM_ASSEMBLY_WORKFLOW.md