Meadow.Foundation.Sensors.Light.Max44009

Max44009
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

The Max44009 is an analog ambient light sensor.

Code Example

Max44009 sensor;

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

    sensor = new Max44009(Device.CreateI2cBus());

    // Example that uses an IObservable subscription to only be notified when the filter is satisfied
    var consumer = Max44009.CreateObserver(
        handler: result => Resolver.Log.Info($"Observer: filter satisfied: {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)
            {
                // 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));
}

Sample project(s) available on GitHub

Wiring Example

To wire a Max44009 to your Meadow board, connect the following:

Max44009	Meadow Pin
SCL	D08
SDA	D07
GND	GND
VCC	3V3

It should look like the following diagram:

Code Example​

Wiring Example​

Code Example

Wiring Example