com.diozero.sandpit

Class HCSR04UsingEvents

java.lang.Object

com.diozero.sandpit.HCSR04UsingEvents

All Implemented Interfaces:

DistanceSensorInterface, InputEventListener<DigitalInputEvent>, Closeable, AutoCloseable

public class HCSR04UsingEvents
extends Object
implements DistanceSensorInterface, Closeable, InputEventListener<DigitalInputEvent>

Note this version doesn't work as well as the event-based HCSR04UsingEvents version as the ns event timings aren't from the raw device unfortunately, only as they get processed in Java 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 Pi4j: sudo java -classpath dio-zero-0.3-SNAPSHOT.jar:pi4j-core-1.1-SNAPSHOT.jar com.diozero.sandpit.HCSR04UsingEvents 17 27 JDK Device I/O: sudo java -classpath dio-zero-0.3-SNAPSHOT.jar com.diozero.sandpit.HCSR04UsingEvents 17 27

Constructor Summary

Constructors

Constructor and Description
HCSR04UsingEvents(int triggerGpioNum, int echoGpioNum) Initialise GPIO to echo and trigger pins

Method Summary

Modifier and Type	Method and Description
void	close() Free device GPIOs
float	getDistanceCm() Send a pulse to HCSR04 and compute the echo to obtain distance
static void	main(String[] args)
void	valueChanged(DigitalInputEvent event)

Methods inherited from class java.lang.Object

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

Constructor Detail

HCSR04UsingEvents

public HCSR04UsingEvents(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 Detail

main

public static void main(String[] args)

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 Closeable

Specified by:

close in interface AutoCloseable

valueChanged

public void valueChanged(DigitalInputEvent event)

Specified by:

valueChanged in interface InputEventListener<DigitalInputEvent>