Remarks

HC-SR04
Status	Not working
Source code	GitHub
NuGet package	Not published

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.

Purchasing

The HC-SR04 sensor is available from Sparkfun:

• Ultrasonic Sensor - HC-SR04

Sample projects available on GitHub

Wiring Example

Characteristic	Locus
Inheritance	System.Object > Hcsr04
Namespace	Meadow.Foundation.Sensors.Distance
Assembly	HCSR04.dll

Syntax

public class Hcsr04 : IRangeFinder

Constructors

Hcsr04(IDigitalOutputPort, IDigitalInputPort)

Create a new HCSR04 object

Declaration

public Hcsr04(IDigitalOutputPort triggerPort, IDigitalInputPort echoPort)

Parameters

Type	Name	Description
IDigitalOutputPort	triggerPort
IDigitalInputPort	echoPort

Hcsr04(IIODevice, IPin, IPin)

Create a new HCSR04 object with an IO Device

Declaration

public Hcsr04(IIODevice device, IPin triggerPin, IPin echoPin)

Parameters

Type	Name	Description
IIODevice	device
IPin	triggerPin
IPin	echoPin

Fields

echoPort

Echo Pin.

Declaration

protected IDigitalInputPort echoPort

Field Value

Type	Description
IDigitalInputPort

tickStart

Declaration

protected long tickStart

Field Value

Type	Description
System.Int64

triggerPort

Trigger Pin.

Declaration

protected IDigitalOutputPort triggerPort

Field Value

Type	Description
IDigitalOutputPort

Properties

CurrentDistance

Returns current distance detected in cm.

Declaration

public float CurrentDistance { get; }

Property Value

Type	Description
System.Single

MaximumDistance

Maximum valid distance in cm (CurrentDistance returns -1 if above).

Declaration

public float MaximumDistance { get; }

Property Value

Type	Description
System.Single

MinimumDistance

Minimum valid distance in cm (CurrentDistance returns -1 if below).

Declaration

public float MinimumDistance { get; }

Property Value

Type	Description
System.Single

Methods

MeasureDistance()

Sends a trigger signal

Declaration

public void MeasureDistance()

Events

DistanceDetected

Raised when an received a rebound trigger signal

Declaration

public event EventHandler<DistanceEventArgs> DistanceDetected

Event Type

Type	Description
System.EventHandler<DistanceEventArgs>