TrailCurrent Air Quality Module

Air quality sensor module for monitoring environmental conditions including temperature, humidity, and air quality metrics.

Hardware Overview

• Function: Environmental monitoring module combining temperature, humidity, and air quality sensing
• Key Features:
  • DHT22 temperature and humidity sensor
  • Air quality sensing capability
  • Compact design suitable for integration into larger systems
  • PlatformIO-based firmware for configuration and operation

Hardware Requirements

Components

• Sensors:

  • DHT22 temperature/humidity sensor
  • Air quality sensor module

• Connectors:

  • JST XH 4-pin connectors for power and signal distribution

KiCAD Library Dependencies

This project uses the consolidated TrailCurrentKiCADLibraries.

Setup:

# Clone the library
git clone git@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 /path/to/EDA/TrailCurrentAirQualityModule/TrailCurrentAirQualityModule.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
   • All 3D models should load from the consolidated library path
   • Models use relative ${TRAILCURRENT_3DMODEL_DIR} references

Firmware

See src/ directory for PlatformIO-based firmware.

Setup:

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

# Build firmware
pio run -d /path/to/project

# Upload to board
pio run -t upload -d /path/to/project

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:

• Firmware receives WiFi credentials via CAN Bus (ID 0x01) from the TrailCurrent system
• For standalone development/testing without the TrailCurrent system, create a secrets.h file in src/:

  // Copy to src/secrets.h for local development only
  // NEVER commit this file - it's in .gitignore
  const char* ssid = "YOUR_SSID_HERE";
  const char* password = "YOUR_PASSWORD_HERE";

Future Enhancement: WiFi credential configuration will be fully implemented via CAN Bus protocol, allowing credentials to be distributed from the TrailCurrent system without firmware modifications.

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: This project supports automated assembly using JLCPCB
  • See BOM_ASSEMBLY_WORKFLOW.md for detailed assembly workflow
  • Component library includes LCSC, Mouser, and DigiKey part numbers for flexible sourcing

Documentation

• Schematic: EDA/TrailCurrentAirQualityModule/TrailCurrentAirQualityModule.kicad_sch
• PCB Layout: EDA/TrailCurrentAirQualityModule/TrailCurrentAirQualityModule.kicad_pcb

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 to the main repository.

Support

For questions about:

• KiCAD setup: See KICAD_ENVIRONMENT_SETUP.md
• Library consolidation: See CONNECTOR_CONSOLIDATION_SUMMARY.md
• Assembly workflow: See BOM_ASSEMBLY_WORKFLOW.md