Meadow.Foundation.Sensors.Light.Bh1750 1.3.1.1-beta

Meadow.Foundation.Sensors.Light.Bh1750

Bh1750 I2C luminance and color light sensor

The Bh1750 library is designed for the Wilderness Labs Meadow .NET IoT platform and is part of Meadow.Foundation

The Meadow.Foundation peripherals library is an open-source repository of drivers and libraries that streamline and simplify adding hardware to your C# .NET Meadow IoT application.

For more information on developing for Meadow, visit developer.wildernesslabs.co, to view all Wilderness Labs open-source projects, including samples, visit github.com/wildernesslabs

Usage

Bh1750 sensor;

public override Task Initialize()
{
    Resolver.Log.Info("Initialize...");

    var i2c = Device.CreateI2cBus();
    sensor = new Bh1750(
        i2c,
        measuringMode: Mode.ContinuouslyHighResolutionMode, // the various modes take differing amounts of time.
        lightTransmittance: 1 // lower this to increase sensitivity, for instance, if it's behind a semi opaque window
        ); 

    // Example that uses an IObservable subscription to only be notified when the filter is satisfied
    var consumer = Bh1750.CreateObserver(
        handler: result => Resolver.Log.Info($"Observer: filter satisifed: {result.New.Lux:N2}Lux, old: {result.Old?.Lux:N2}Lux"),
        
        // only notify if the visible light changes by 100 lux (put your hand over the sensor to trigger)
        filter: result => {
            if (result.Old is { } old) { //c# 8 pattern match syntax. checks for !null and assigns var.
                // returns true if > 100lux change
                return ((result.New - old).Abs().Lux > 100);
            }
            return false;
        });
    sensor.Subscribe(consumer);

    // classical .NET events can also be used:
    sensor.Updated += (sender, result) => Resolver.Log.Info($"Light: {result.New.Lux:N2}Lux");

    return Task.CompletedTask;
}

public override async Task Run()
{
    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($" Light: {result.Lux:N2}Lux");

    sensor.StartUpdating(TimeSpan.FromSeconds(1));
}