nanoFramework.HomeAssistant.MqttDiscovery

Easily integrate your .NET nanoFramework devices with Home Assistant using MQTT Auto Discovery.
This library lets your devices automatically register entities like sensors and switches without any manual configuration in Home Assistant.

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Features

• Home Assistant MQTT Auto Discovery support
• Simple API for defining sensors, switches, and other entities
• Built-in support for state updates and command handling
• Supports MQTT authentication
• Compatible with .NET nanoFramework for ESP32 and similar devices

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Installation

You can install the package via NuGet:

nuget install nf.HomeAssistant.MqttDiscovery

Example usage

using nanoFramework.HomeAssistant.MqttDiscovery;
using System.Device.Gpio;

// Create the Home Assistant client
var homeassistant = new HomeAssistant(
    "Second Test",
    "192.168.88.172",
    username: "homeassistant",
    password: "password");

// Example: Add a switch entity
var relay = homeassistant.AddSwitch("Switch number 1", "OFF");
relay.OnChange += (s, e) =>
{
    if (e == "ON")
    {
        relayPin.Write(PinValue.High);
    }
    else
    {
        relayPin.Write(PinValue.Low);
    }
};

// Example: Add a temperature sensor
var temperatureSensor = homeassistant.AddSensor("Temperature", "°C", "18", DeviceClass.Temperature);
temperatureSensor.OnChange += (s, e) =>
{
    Console.WriteLine($"Temperature changed to {e}");
};

// Example: Add select options
var dayOfWeek = homeassistant.AddOption("Day of week", new [] { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" } , "Tuesday");
dayOfWeek.OnChange += (s, e) =>
{
    Console.WriteLine($"Day of week changed to {e}");
};

// Connect to home assistant
homeassistant.Connect();

// Set the relay to off
relay.SetState("OFF"); // This publishes an MQTT event to the switch's state topic. Home assistant will show the new state of off.
relayPin.Write(PinValue.Low);

// Report the current temperature to Home Assistant
var currentTemperature = GetCurrentTemperature();
temperatureSensor.SetState($"{currentTemperature}");

Thread.Sleep(Timeout.Infinite);

This example:

• Creates a Home Assistant connection over MQTT
• Adds a switch that responds to Home Assistant commands
• Adds a temperature sensor that reports values automatically

Configuration

Make sure your Home Assistant installation has the MQTT integration enabled and is configured to allow Auto Discovery.

You can verify this by checking Configuration → Devices & Services → MQTT.

For more details: Home Assistant MQTT Discovery Docs

Entity Types Supported

• Sensors
  • All types defined on https://www.home-assistant.io/integrations/sensor/#device-class
• Switches
• Text inputs
• Select options

License

This project is licensed under the MIT License.

Contributing

Contributions, issues, and feature requests are welcome!

Feel free to open an issue or pull request on the GitHub repository.