Remarks

Sht4x
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sht4x sensor;

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

    sensor = new Sht4x(Device.CreateI2cBus());

    var consumer = Sht4x.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 is { } old)
            {
                return (
                (result.New.Temperature.Value - old.Temperature.Value).Abs().Celsius > 0.5
                &&
                (result.New.Humidity.Value.Percent - old.Humidity.Value.Percent) > 0.05
                );
            }
            return false;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  Temperature: {result.New.Temperature?.Celsius:N2}C");
        Resolver.Log.Info($"  Relative Humidity: {result.New.Humidity:N2}%");
    };

    return Task.CompletedTask;
}

public override async Task Run()
{
    var conditions = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {conditions.Temperature?.Celsius:N2}C");
    Resolver.Log.Info($"  Relative Humidity: {conditions.Humidity?.Percent:N2}%");

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

Sample project(s) available on GitHub

Wiring Example

To wire a Sht4x to your Meadow board, connect the following:

Sht4x	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

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>>> > Sht4x
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	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	Sht4x.dll

Syntax

public class Sht4x : ByteCommsSensorBase<(Units.Temperature? Temperature, RelativeHumidity? Humidity)>, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity)>, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity)>, IDisposable, ITemperatureSensor, IHumiditySensor

Constructors

Sht4x(II2cBus, Byte)

Create a new SHT4x object

Declaration

public Sht4x(II2cBus i2cBus, byte address = null)

Parameters

Type	Name	Description
II2cBus	i2cBus	I2cBus
System.Byte	address	Sensor address (0x44 or 0x45)

Properties

Humidity

The humidity, in percent relative humidity, from the last reading

Declaration

public RelativeHumidity? Humidity { get; }

Property Value

Type	Description
System.Nullable<RelativeHumidity>

ReadPrecision

Precision of sensor reading

Declaration

public Sht4x.Precision ReadPrecision { get; protected set; }

Property Value

Type	Description
Sht4x.Precision

Temperature

The curren temperature -from the last reading.

Declaration

public Units.Temperature? Temperature { get; }

Property Value

Type	Description
System.Nullable<Units.Temperature>

Methods

GetDelayForPrecision(Sht4x.Precision)

Returns the appropriate delay in ms for the set precision

Declaration

protected int GetDelayForPrecision(Sht4x.Precision precision)

Parameters

Type	Name	Description
Sht4x.Precision	precision	Precision to calculate delay

Returns

Type	Description
System.Int32

RaiseEventsAndNotify(IChangeResult<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity)>)

Raise events for subscribers

Declaration

protected override void RaiseEventsAndNotify(IChangeResult<(Units.Temperature? Temperature, RelativeHumidity? Humidity)> changeResult)

Parameters

Type	Name	Description
IChangeResult<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>>>	changeResult

ReadSensor()

Get a reading from the sensor and set the Temperature and Humidity properties.

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()

Events

HumidityUpdated

Humidity changed event handler

Declaration

public event EventHandler<IChangeResult<RelativeHumidity>> HumidityUpdated

Event Type

Type	Description
EventHandler<IChangeResult<RelativeHumidity>>

TemperatureUpdated

Temperature changed event handler

Declaration

public event EventHandler<IChangeResult<Units.Temperature>> TemperatureUpdated

Event Type

Type	Description
EventHandler<IChangeResult<Units.Temperature>>