Model temperature states on a microcontroller

This .NET nanoFramework sample shows how Raven's domain modeling fits close to a hardware boundary. A union represents the sensor states, and one exhaustive match translates those states into GPIO output.

union TemperatureState {
    case SensorUnavailable
    case Comfortable(celsius: double)
    case TooHot(celsius: double)
}

func ActOn(state: TemperatureState, alarm: GpioPin) {
    match state {
        .SensorUnavailable => alarm.Write(PinValue.High)
        .Comfortable(_) => alarm.Write(PinValue.Low)
        .TooHot(_) => alarm.Write(PinValue.High)
    }
}

What the sample shows

• A missing sensor is a named state rather than an invented numeric reading.
• Each successful state carries its temperature.
• ActOn handles the complete state space and keeps the GPIO effect separate from sensor classification.
• Raven uses the nanoFramework GpioPin and PinValue types directly.

The complete sample reads a DHT sensor, owns device resources with use, runs an unconditional device loop, and packages the program as an NFMRK2 image.

Continue with building embedded IoT applications for project setup, packaging, hardware boundaries, and links to the temperature and Pico blinky samples.