Remarks

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

Code Example

RgbPwmLed onboardLed;
SwitchingAnemometer anemometer;

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

    //==== onboard LED
    onboardLed = new RgbPwmLed(
        redPwmPin: Device.Pins.OnboardLedRed,
        greenPwmPin: Device.Pins.OnboardLedGreen,
        bluePwmPin: Device.Pins.OnboardLedBlue,
        CommonType.CommonAnode);

    //==== create the anemometer
    anemometer = new SwitchingAnemometer(Device.Pins.A01);

    //==== classic events example
    anemometer.WindSpeedUpdated += (sender, result) =>
    {
        Resolver.Log.Info($"new speed: {result.New.KilometersPerHour:n1}kmh, old: {result.Old?.KilometersPerHour:n1}kmh");
        OutputWindSpeed(result.New);
    };

    //==== IObservable example
    var observer = SwitchingAnemometer.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"new speed (from observer): {result.New.KilometersPerHour:n1}kmh, old: {result.Old?.KilometersPerHour:n1}kmh");
        },
        null
        );
    anemometer.Subscribe(observer);

    return Task.CompletedTask;
}

public override Task Run()
{
    // start raising updates
    anemometer.StartUpdating();
    Resolver.Log.Info("Hardware initialized.");

    return Task.CompletedTask;
}

/// <summary>
/// Displays the windspeed on the onboard LED as full red @ >= `10km/h`,
/// blue @ `0km/h`, and a proportional mix, in between those speeds.
/// </summary>
/// <param name="windspeed"></param>
void OutputWindSpeed(Speed windspeed)
{
    // `0.0` - `10kmh`
    int r = (int)windspeed.KilometersPerHour.Map(0f, 10f, 0f, 255f);
    int b = (int)windspeed.KilometersPerHour.Map(0f, 10f, 255f, 0f);

    var wspeedColor = Color.FromRgb(r, 0, b);
    onboardLed.SetColor(wspeedColor);
}

Sample project(s) available on GitHub

Characteristic	Locus
Inheritance	System.Object ObservableBase<Speed> SamplingSensorBase<Speed> PollingSensorBase<Speed> > SwitchingAnemometer
Implements	ISamplingSensor<Speed> ISamplingSensor<Speed> IAnemometer
Inherited Members	SamplingSensorBase<Speed>.samplingLock SamplingSensorBase<Speed>.Updated SamplingSensorBase<Speed>.SamplingTokenSource SamplingSensorBase<Speed>.Conditions SamplingSensorBase<Speed>.IsSampling SamplingSensorBase<Speed>.UpdateInterval SamplingSensorBase<Speed>.RaiseEventsAndNotify(IChangeResult<>) SamplingSensorBase<Speed>.Read() ObservableBase<Speed>.observers ObservableBase<Speed>.NotifyObservers(IChangeResult<>) Meadow.Foundation.ObservableBase<Speed>.Subscribe(IObserver<>) Meadow.Foundation.ObservableBase<Speed>.CreateObserver(Action<>, System.Nullable<Predicate<IChangeResult<UNIT>>>)
Namespace	Meadow.Foundation.Sensors.Weather
Assembly	SwitchingAnemometer.dll

Syntax

public class SwitchingAnemometer : PollingSensorBase<Speed>, ISamplingSensor<Speed>, ISamplingSensor<Speed>, IAnemometer

Constructors

SwitchingAnemometer(IDigitalInputPort)

Creates a new switching anemometer using the specific IDigitalInputPort.

Declaration

public SwitchingAnemometer(IDigitalInputPort inputPort)

Parameters

Type	Name	Description
IDigitalInputPort	inputPort

SwitchingAnemometer(IPin)

Creates a new SwitchingAnemometer using the specific digital input on the device.

Declaration

public SwitchingAnemometer(IPin digitalInputPin)

Parameters

Type	Name	Description
IPin	digitalInputPin

Properties

KmhPerSwitchPerSecond

Calibration for how fast the wind speed is when the switch is hit once per second. Used to calculate the wind speed based on the time duration between switch events. Default is 2.4kmh.

Declaration

public float KmhPerSwitchPerSecond { get; set; }

Property Value

Type	Description
System.Single

NoWindTimeout

Time to wait if no events come in to register a zero speed wind

Declaration

public TimeSpan NoWindTimeout { get; set; }

Property Value

Type	Description
TimeSpan

OneTimeReadDuration

Time to capture samples for a one time Read if IsSampling is false

Declaration

public TimeSpan OneTimeReadDuration { get; set; }

Property Value

Type	Description
TimeSpan

SampleCount

Number of samples to take for a reading

Declaration

public int SampleCount { get; set; }

Property Value

Type	Description
System.Int32

WindSpeed

The current wind speed

Declaration

public Speed? WindSpeed { get; protected set; }

Property Value

Type	Description
System.Nullable<Speed>

Methods

RaiseEventsAndNotify(IChangeResult<Speed>)

Raise events for subcribers and notify of value changes

Declaration

protected override void RaiseEventsAndNotify(IChangeResult<Speed> changeResult)

Parameters

Type	Name	Description
IChangeResult<Speed>	changeResult	The updated sensor data

ReadSensor()

Reads data from the sensor

Declaration

protected override Task<Speed> ReadSensor()

Returns

Type	Description
Task<Speed>	The latest sensor reading

Overrides

Meadow.Foundation.SamplingSensorBase<Speed>.ReadSensor()

StartUpdating(Nullable<TimeSpan>)

Starts continuously sampling the sensor

This method also starts raising Updated events and IObservable subscribers getting notified. Use the standbyDuration parameter to specify how often events and notifications are raised/sent.

Declaration

public override void StartUpdating(TimeSpan? updateInterval = null)

Parameters

Type	Name	Description
System.Nullable<TimeSpan>	updateInterval

StopUpdating()

Stops the driver from raising wind speed events

Declaration

public override void StopUpdating()

Overrides

Meadow.Foundation.PollingSensorBase<Speed>.StopUpdating()

SwitchIntervalToKmh(TimeSpan)

A wind speed of 2.4km/h causes the switch to close once per second

Declaration

protected float SwitchIntervalToKmh(TimeSpan interval)

Parameters

Type	Name	Description
TimeSpan	interval	The interval between signals

Returns

Type	Description
System.Single

Events

WindSpeedUpdated

Raised when the speed of the wind changes

Declaration

public event EventHandler<IChangeResult<Speed>> WindSpeedUpdated

Event Type

Type	Description
EventHandler<IChangeResult<Speed>>