Package com.diozero.devices

Class HCSR04

java.lang.Object

com.diozero.devices.HCSR04

All Implemented Interfaces:

DistanceSensorInterface, SensorInterface, Closeable, AutoCloseable

public class HCSR04
extends Object
implements DistanceSensorInterface

User's manual: https://docs.google.com/document/d/1Y-yZnNhMYy7rwhAgyL_pfa39RsB-x2qR4vP8saG73rE/edit# Product specification: http://www.micropik.com/PDF/HCSR04.pdf Provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm You only need to supply a short 10uS pulse to the trigger input to start the ranging, and then the module will send out an 8 cycle burst of ultrasound at 40 kHz and raise its echo. The Echo is a distance object that is pulse width and the range in proportion. We suggest to use over 60ms measurement cycle, in order to prevent trigger signal to the echo signal

Constructor Summary

Constructors

Constructor	Description
HCSR04(int triggerGpioNum, int echoGpioNum)	Initialise GPIO to echo and trigger pins

Method Summary

Modifier and Type	Method	Description
void	close()	Free device GPIOs
float	getDistanceCm()	Send a pulse to HCSR04 and compute the echo to obtain distance

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

HCSR04

public HCSR04(int triggerGpioNum,
int echoGpioNum)
       throws RuntimeIOException

Initialise GPIO to echo and trigger pins

Parameters:

triggerGpioNum - GPIO connected to the HC-SR04 trigger pin

echoGpioNum - GPIO connected to the HC-SR04 echo pin

Throws:

RuntimeIOException - if an I/O error occurs

Method Details

getDistanceCm

public float getDistanceCm()
                    throws RuntimeIOException

Send a pulse to HCSR04 and compute the echo to obtain distance

Specified by:

getDistanceCm in interface DistanceSensorInterface

Returns:

distance in cm

Throws:

RuntimeIOException - if an I/O error occurs

close

public void close()

Free device GPIOs

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface SensorInterface