Meadow.Foundation.Sensors.Atmospheric.Ccs811 1.3.1.1-beta

Meadow.Foundation.Sensors.Atmospheric.Ccs811

Ccs811 I2C VOC Air Quality Sensor

The Ccs811 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

Ccs811 sensor;

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

    var i2cBus = Device.CreateI2cBus(Meadow.Hardware.I2cBusSpeed.Fast);
    sensor = new Ccs811(i2cBus);

    var consumer = Ccs811.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer triggered:");
            Resolver.Log.Info($"   new CO2: {result.New.Co2?.PartsPerMillion:N1}ppm, old: {result.Old?.Co2?.PartsPerMillion:N1}ppm.");
            Resolver.Log.Info($"   new VOC: {result.New.Voc?.PartsPerBillion:N1}ppb, old: {result.Old?.Voc?.PartsPerBillion:N1}ppb.");
        },
        filter: result =>
        {
            //c# 8 pattern match syntax. checks for !null and assigns var.
            if (result.Old is { } old)
            {
                return (
                (result.New.Co2.Value - old.Co2.Value).Abs().PartsPerMillion > 1000 // 1000ppm
                  &&
                (result.New.Voc.Value - old.Voc.Value).Abs().PartsPerBillion > 100 // 100ppb
                );
            }
            return false;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"CO2: {result.New.Co2.Value.PartsPerMillion:n1}ppm, VOC: {result.New.Voc.Value.PartsPerBillion:n1}ppb");
    };

    return Task.CompletedTask;
}

public override async Task Run()
{
    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  CO2: {result.Co2.Value.PartsPerMillion:n1}ppm");
    Resolver.Log.Info($"  VOC: {result.Voc.Value.PartsPerBillion:n1}ppb");

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