Remarks

Htu31d
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Htu31d? sensor;

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

    sensor = new Htu31d(Device.CreateI2cBus());

    var consumer = Htu31d.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: Temp changed by threshold; new temp: {result.New.Temperature?.Celsius:N2}C, old: {result.Old?.Temperature?.Celsius:N2}C");
        },
        filter: result =>
        {
            //c# 8 pattern match syntax. checks for !null and assigns var.
            if (result.Old?.Temperature is { } oldTemp &&
                result.Old?.Humidity is { } oldHumidity &&
                result.New.Temperature is { } newTemp &&
                result.New.Humidity is { } newHumidity)
            {
                return ((newTemp - oldTemp).Abs().Celsius > 0.5 &&
                        (newHumidity - oldHumidity).Percent > 0.05);
            }
            return false;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  Temperature: {result.New.Temperature?.Celsius:F1}C");
        Resolver.Log.Info($"  Relative Humidity: {result.New.Humidity?.Percent:F1}%");
    };

    return Task.CompletedTask;
}

public override async Task Run()
{
    if (sensor == null) { return; }

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result.Temperature?.Celsius:F1}C");
    Resolver.Log.Info($"  Relative Humidity: {result.Humidity:F1}%");

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

Sample project(s) available on GitHub

Characteristic	Locus
Inheritance	System.Object ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> SamplingSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> PollingSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> ByteCommsSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> Htux1dBase > Htu31d
Implements	ISamplingSensor<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> ISamplingSensor<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>> IDisposable ITemperatureSensor IHumiditySensor
Inherited Members	Htux1dBase.TemperatureUpdated Htux1dBase.HumidityUpdated Htux1dBase.DEFAULT_SPEED Htux1dBase.Temperature Htux1dBase.Humidity Htux1dBase.SerialNumber Htux1dBase.RaiseEventsAndNotify(IChangeResult<ValueTuple<Nullable<Units.Temperature>, Nullable<RelativeHumidity>>>) ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Peripheral ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.ReadBuffer ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.WriteBuffer ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Init(Int32, Int32) ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Dispose(Boolean) ByteCommsSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Dispose() PollingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.StartUpdating(Nullable<TimeSpan>) PollingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.StopUpdating() SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.samplingLock SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Updated SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.SamplingTokenSource SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Conditions SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.IsSampling SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.UpdateInterval SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.ReadSensor() SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.RaiseEventsAndNotify(IChangeResult<>) SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.Read() ObservableBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.observers ObservableBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>.NotifyObservers(IChangeResult<>) Meadow.Foundation.ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>>.Subscribe(IObserver<>) Meadow.Foundation.ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>>.CreateObserver(Action<>, System.Nullable<Predicate<IChangeResult<UNIT>>>)
Namespace	Meadow.Foundation.Sensors.Atmospheric
Assembly	Htux1d.dll

Syntax

public class Htu31d : Htux1dBase, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity)>, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity)>, IDisposable, ITemperatureSensor, IHumiditySensor

Constructors

Htu31d(II2cBus, Byte, Nullable<TimeSpan>)

Create a new Htu31d temperature and humidity sensor.

Declaration

public Htu31d(II2cBus i2cBus, byte address = null, TimeSpan? updateInterval = null)

Parameters

Type	Name	Description
II2cBus	i2cBus	I2CBus (default to 100 KHz).
System.Byte	address	Sensor address (default to 0x40).
System.Nullable<TimeSpan>	updateInterval	Update interval, defaults to 1 sec if null

Methods

Heater(Boolean)

Turn the heater on or off

Declaration

public void Heater(bool heaterOn)

Parameters

Type	Name	Description
System.Boolean	heaterOn	Heater status, true = turn heater on, false = turn heater off

ReadSensor()

Read atmospheric data from sensor

Declaration

protected override Task<(Units.Temperature? Temperature, RelativeHumidity? Humidity)> ReadSensor()

Returns

Type	Description
Task<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>>

Overrides

Meadow.Foundation.SamplingSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>>.ReadSensor()

Reset()

Reset the sensor

Declaration

public void Reset()