Meadow.Foundation.Sensors.Distance.Hcsr04

Hcsr04
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

The HC-SR04 ultrasonic sensor uses sonar to determine distance to an object (like bats). It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package.

Code Example

Hcsr04 hCSR04;

public override Task Initialize()
{
    Resolver.Log.Info($"Hello HC-SR04 sample");

    hCSR04 = new Hcsr04(
        triggerPin: Device.Pins.D05,
        echoPin: Device.Pins.D06);
    hCSR04.Updated += HCSR04_DistanceUpdated;

    return Task.CompletedTask;
}

public override Task Run()
{
    while (true)
    {
        // Sends a trigger signal
        hCSR04.MeasureDistance();
        Thread.Sleep(2000);
    }
}

private void HCSR04_DistanceUpdated(object sender, IChangeResult<Meadow.Units.Length> e)
{
    Resolver.Log.Info($"Distance (cm): {e.New.Centimeters}");
}

Sample project(s) available on GitHub

Wiring Example

Class Hcsr04

HCSR04 Distance Sensor - driver not complete

Assembly: Hcsr04.dll

View Source

Declaration

public class Hcsr04 : SamplingSensorBase<Length>, IObservable<IChangeResult<Length>>, IRangeFinder, ISamplingSensor<Length>, ISensor<Length>, ISensor, ISamplingSensor, IDisposable

Inheritance: System.Object -> Meadow.Foundation.ObservableBase<UNIT>

Derived:
Meadow.Foundation.ICs.IOExpanders.SerialWombatBase.Hcsr04

Implements:
System.IObservable<Meadow.IChangeResult<Meadow.Units.Length>>, Meadow.Peripherals.Sensors.Distance.IRangeFinder, Meadow.Peripherals.Sensors.ISamplingSensor<Meadow.Units.Length>, Meadow.Peripherals.Sensors.ISensor<Meadow.Units.Length>, Meadow.Peripherals.Sensors.ISensor, Meadow.Peripherals.Sensors.ISamplingSensor, System.IDisposable

Properties

Distance

Returns current distance

View Source

Declaration

public Length? Distance { get; protected set; }

MinimumDistance

Minimum valid distance in cm

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Declaration

public double MinimumDistance { get; }

MaximumDistance

Maximum valid distance in cm

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Declaration

public double MaximumDistance { get; }

IsDisposed

Is the object disposed

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Declaration

public bool IsDisposed { get; }

Fields

triggerPort

Port for trigger Pin

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Declaration

protected IDigitalOutputPort? triggerPort

echoPort

Port for echo Pin

View Source

Declaration

protected IDigitalInterruptPort? echoPort

Methods

MeasureDistance()

Sends a trigger signal

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Declaration

public virtual void MeasureDistance()

ReadSensor()

Reads data from the sensor

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Declaration

protected override Task<Length> ReadSensor()

Returns

System.Threading.Tasks.Task<Meadow.Units.Length>: The latest sensor reading### StartUpdating(TimeSpan?) Starts continuously sampling the sensor

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Declaration

public override void StartUpdating(TimeSpan? updateInterval = null)

Parameters

Type	Name
System.Nullable<System.TimeSpan>	updateInterval

StopUpdating()

Stops sampling the sensor

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Declaration

public override void StopUpdating()

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

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Declaration

public void Dispose()

Dispose(bool)

Dispose of the object

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Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	Is disposing

Implements

• System.IObservable<Meadow.IChangeResult<Meadow.Units.Length>>
• Meadow.Peripherals.Sensors.Distance.IRangeFinder
• Meadow.Peripherals.Sensors.ISamplingSensor<Meadow.Units.Length>
• Meadow.Peripherals.Sensors.ISensor<Meadow.Units.Length>
• Meadow.Peripherals.Sensors.ISensor
• Meadow.Peripherals.Sensors.ISamplingSensor
• System.IDisposable