GassiMeter

A .NET application that monitors Home Assistant entities, checks weather conditions, and displays visual notifications on WLED-compatible LED strips.

Overview

GassiMeter integrates three main components:

1. Home Assistant Integration (optional) - Monitor entity states
2. Weather Monitoring - Check rain forecasts via OpenWeather API
3. LED Visualization - Display information on WLED-compatible LED strips

The application runs continuously, checking conditions at configurable intervals and updating LED displays accordingly.

Requirements

• .NET 9.0 or later
• WLED-compatible LED strip with ESP32
• OpenWeather API key (free tier available)
• Home Assistant instance (optional)

3D Printed files

For the legend (show what color means what) and scale I created a few STL files as well as the Blend File (for Blender) so you can change the text if you decide to use my design:

https://www.thingiverse.com/thing:7117297

Configuration

config.json

The application includes a config.json file that needs to be configured with your specific settings:

Hass (Optional)

• Sensor: The Home Assistant entity ID to monitor
• RequiredState: The required state value to check for

Weather (Required)

• Longitude: Geographic longitude for weather data
• Latitude: Geographic latitude for weather data
• Delay: Interval between weather checks (format: "HH:MM:SS", default: "00:02:00")

Wled (Required)

• Url: WLED device JSON API endpoint
• Count: Number of LEDs to control (default: 60)
• Start: Starting LED index (default: 0)
• MinutesPerLed: Minutes represented per LED (default: 2)
• Brightness: LED brightness level 0-255 (default: 128)
• Colors: Array of color-to-rain-amount mappings for LED display
  • ColorCode: 6-character hex color code (e.g., "32FF32" for green)
  • RainAmount: Rain amount in mm/hour that triggers this color
  • Required values: Must include entries for RainAmount: -1 (missing data) and RainAmount: 0 (no rain)
  • Colors are interpolated between defined values for smooth gradients
  • Example color scheme:
    • -1: "000000" (LEDs off - missing historical data)
    • 0: "32FF32" (Green - sunny/no rain)
    • 0.5: "00B4FF" (Light Blue - drizzle)
    • 2.5: "0032C8" (Blue - light rain)
    • 5: "FF3296" (Pink - heavy rain/thunderstorm)
    • 10: "DC1414" (Red - very heavy rain)
    • 20: "FFC800" (Orange - extreme weather)

OperationTime (Optional)

• FromTime: Start time for operation (format: "HH:MM:SS", e.g., "06:00:00")
• ToTime: End time for operation (format: "HH:MM:SS", e.g., "22:00:00")

secrets.json

1. Copy secrets.example.json to secrets.json
2. Fill in your actual values:

• HassBearer: Home Assistant long-lived access token (only required if using Hass integration)
• WeatherApiKey: OpenWeather API key (required)

API Usage and Rate Limits

OpenWeather API

The application uses the OpenWeather API to fetch hourly rain forecasts. The free tier includes:

• 1,000 API calls per day

Important: With the default 2-minute interval, running 24/7 will make approximately 720 calls per day, which is within the free tier limit. If you want to reduce the interval make sure you set a limit at WeatherApi. One Call per minute is above the free tier when running 24h.

Getting Started

Option 1: Running with .NET

1. Clone the repository
2. Install .NET 9.0 SDK
3. Configure config.json with your location and device settings
4. Copy secrets.example.json to secrets.json and add your API keys
5. Get your OpenWeather API key from openweathermap.org
6. Configure your WLED device and note its IP address
7. Build and run the application:

dotnet build
dotnet run

Option 2: Running with Docker

1. Clone the repository
2. Configure config.json and secrets.json on your host machine
3. Build the Docker image:

docker build -t gassimeter .

4. Run the container with volume mounts for configuration:

docker run -d \
  --name gassimeter \
  -v /path/to/your/config.json:/app/config.json \
  -v /path/to/your/secrets.json:/app/secrets.json \
  gassimeter

Replace /path/to/your/ with the actual paths to your configuration files on the host system.

Docker Volume Configuration

The application requires two configuration files that should be mounted as volumes:

• config.json: Application settings including weather location, WLED device URL, and color mappings
• secrets.json: API keys and sensitive credentials

Example with absolute paths:

docker run -d \
  --name gassimeter \
  -v /home/user/gassimeter/config.json:/app/config.json \
  -v /home/user/gassimeter/secrets.json:/app/secrets.json \
  gassimeter

This approach keeps your configuration and secrets outside the container, making it easy to update settings without rebuilding the image.

Home Assistant Integration

To use the Home Assistant integration:

1. Generate a long-lived access token in Home Assistant
2. Add the token to secrets.json as HassBearer
3. Configure the Hass section in config.json with your entity and required state
4. If the Hass configuration is omitted, this step will be skipped automatically

WLED Setup

1. Flash your ESP32 with WLED firmware
2. Connect to your WiFi network
3. Note the device's IP address
4. Update the Wled.Url in your config to point to http://[device-ip]/json/state

Troubleshooting

• Configuration errors: Ensure JSON syntax is valid in both config files
• API errors: Verify your OpenWeather API key is valid and active
• WLED connection: Check that the ESP32 is accessible on your network
• Home Assistant: Verify your long-lived token has appropriate permissions

License

This project is open source. Please check the LICENSE file for details.

Gassimeter in Action