com.pi4j.wiringpi

Class GpioInterrupt

java.lang.Object

com.pi4j.wiringpi.GpioInterrupt

public class GpioInterrupt
extends Object

This class provides static methods to configure the native Pi4J library to listen to GPIO interrupts and invoke callbacks into this class. Additionally, this class provides a listener registration allowing Java consumers to subscribe to GPIO pin state changes.

Before using the Pi4J library, you need to ensure that the Java VM in configured with access to the following system libraries:

• pi4j
• wiringPi

This library depends on the wiringPi native system library.
(developed by Gordon Henderson @ http://wiringpi.com/)

Author:

Robert Savage (http://www.savagehomeautomation.com)

See Also:

https://www.pi4j.com/

Method Summary

Modifier and Type	Method and Description
static void	addListener(GpioInterruptListener listener) Java consumer code can all this method to register itself as a listener for pin state changes.
static int	disablePinStateChangeCallback(int pin) This method is used to instruct the native code to stop the monitoring thread monitoring interrupts on the selected GPIO pin.
static int	enablePinStateChangeCallback(int pin) This method is used to instruct the native code to setup a monitoring thread to monitor interrupts that represent changes to the selected GPIO pin.
static boolean	hasListener(GpioInterruptListener listener) Returns true if the listener is already registered for event callbacks.
static void	removeListener(GpioInterruptListener listener) Java consumer code can all this method to unregister itself as a listener for pin state changes.

Methods inherited from class java.lang.Object

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

Method Detail

enablePinStateChangeCallback

public static int enablePinStateChangeCallback(int pin)

This method is used to instruct the native code to setup a monitoring thread to monitor interrupts that represent changes to the selected GPIO pin.

The GPIO pin must first be exported before it can be monitored.

Parameters:

pin - GPIO pin number (not header pin number; not wiringPi pin number)

Returns:

A return value of a negative number represents an error. A return value of '0' represents success and that the GPIO pin is already being monitored. A return value of '1' represents success and that a new monitoring thread was created to handle the requested GPIO pin number.

disablePinStateChangeCallback

public static int disablePinStateChangeCallback(int pin)

This method is used to instruct the native code to stop the monitoring thread monitoring interrupts on the selected GPIO pin.

Parameters:

pin - GPIO pin number (not header pin number; not wiringPi pin number)

Returns:

A return value of a negative number represents an error. A return value of '0' represents success and that no existing monitor was previously running. A return value of '1' represents success and that an existing monitoring thread was stopped for the requested GPIO pin number.

addListener

public static void addListener(GpioInterruptListener listener)

Java consumer code can all this method to register itself as a listener for pin state changes.

Parameters:

listener - A class instance that implements the GpioInterruptListener interface.

See Also:

GpioInterruptListener, GpioInterruptEvent

removeListener

public static void removeListener(GpioInterruptListener listener)

Java consumer code can all this method to unregister itself as a listener for pin state changes.

Parameters:

listener - A class instance that implements the GpioInterruptListener interface.

See Also:

GpioInterruptListener, GpioInterruptEvent

hasListener

public static boolean hasListener(GpioInterruptListener listener)

Returns true if the listener is already registered for event callbacks.

Parameters:

listener - A class instance that implements the GpioInterruptListener interface.

See Also:

GpioInterruptListener, GpioInterruptEvent