Package com.diozero.devices

Class Button

java.lang.Object

com.diozero.api.GpioDevice

com.diozero.api.GpioInputDevice<DigitalInputEvent>

com.diozero.api.AbstractDigitalInputDevice

com.diozero.api.DigitalInputDevice

com.diozero.devices.Button

All Implemented Interfaces:

DeviceInterface, DigitalInputDeviceInterface, DeviceEventConsumer<DigitalInputEvent>, AutoCloseable, Consumer<DigitalInputEvent>

public class Button
extends DigitalInputDevice

Provides push button related utility methods.

From the ButtonTest example:

 
 try (Button button = new Button(inputPin, GpioPullUpDown.PULL_UP)) {
   button.addListener(event -> Logger.debug("Event: {}", event));
   Logger.debug("Waiting for 10s - *** Press the button connected to input pin " + inputPin + " ***");
   SleepUtil.sleepSeconds(10);
 }
 
 

Controlling an LED with a button ButtonControlledLed:

 
 try (Button button = new Button(buttonPin, GpioPullUpDown.PULL_UP); LED led = new LED(ledPin)) {
   button.whenPressed(nanoTime -> led::on);
   button.whenReleased(nanoTime -> led::off);
   Logger.info("Waiting for 10s - *** Press the button connected to pin {} ***", Integer.valueOf(buttonPin));
   SleepUtil.sleepSeconds(10);
 }
 
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Button.Builder	Button builder.

Field Summary

Fields inherited from class com.diozero.api.AbstractDigitalInputDevice

activeHigh

Fields inherited from class com.diozero.api.GpioDevice

pinInfo

Constructor Summary

Constructors

Constructor	Description
Button(int gpio)
Button(int gpio, GpioPullUpDown pud)
Button(int gpio, GpioPullUpDown pud, GpioEventTrigger trigger)
Button(GpioDeviceFactoryInterface deviceFactory, int gpio, GpioPullUpDown pud)
Button(GpioDeviceFactoryInterface deviceFactory, int gpio, GpioPullUpDown pud, GpioEventTrigger trigger)
Button(GpioDeviceFactoryInterface deviceFactory, PinInfo pinInfo, GpioPullUpDown pud, GpioEventTrigger trigger, boolean activeHigh)

Method Summary

Modifier and Type	Method	Description
boolean	isPressed()	Get the current state.
boolean	isReleased()	Get the current state.
void	whenPressed(LongConsumer consumer)	Action to perform when the button is pressed.
void	whenReleased(LongConsumer consumer)	Action to perform when the button is released.

Methods inherited from class com.diozero.api.DigitalInputDevice

close, getPullUpDown, getTrigger, getValue, isActive, removeListener, setListener

Methods inherited from class com.diozero.api.AbstractDigitalInputDevice

accept, disableDeviceListener, enableDeviceListener, isActiveHigh, waitForActive, waitForActive, waitForInactive, waitForInactive, waitForValue, whenActivated, whenDeactivated

Methods inherited from class com.diozero.api.GpioInputDevice

addListener, hasListeners, removeAllListeners, removeListener

Methods inherited from class com.diozero.api.GpioDevice

getGpio

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.Consumer

andThen

Constructor Details

Button

public Button(int gpio)
       throws RuntimeIOException,
NoSuchDeviceException

Parameters:

gpio - GPIO to which the device is connected.

Throws:

RuntimeIOException - If an I/O error occurs.

NoSuchDeviceException

Button

public Button(int gpio,
GpioPullUpDown pud)
       throws RuntimeIOException

Parameters:

gpio - GPIO to which the button is connected.

pud - Pull up / down configuration (NONE, PULL_UP, PULL_DOWN).

Throws:

RuntimeIOException - If an I/O error occurred.

Button

public Button(int gpio,
GpioPullUpDown pud,
GpioEventTrigger trigger)
       throws RuntimeIOException,
NoSuchDeviceException

Parameters:

gpio - GPIO to which the device is connected

pud - Pull up/down configuration, values: NONE, PULL_UP, PULL_DOWN

trigger - Event trigger configuration, values: NONE, RISING, FALLING, BOTH

Throws:

RuntimeIOException - If an I/O error occurs

NoSuchDeviceException

Button

public Button(GpioDeviceFactoryInterface deviceFactory,
int gpio,
GpioPullUpDown pud)

Button

public Button(GpioDeviceFactoryInterface deviceFactory,
int gpio,
GpioPullUpDown pud,
GpioEventTrigger trigger)
       throws RuntimeIOException,
NoSuchDeviceException

Parameters:

deviceFactory - Device factory to use to provision this digital input device

gpio - GPIO to which the device is connected

pud - Pull up/down configuration, values: NONE, PULL_UP, PULL_DOWN

trigger - Event trigger configuration, values: NONE, RISING, FALLING, BOTH

Throws:

RuntimeIOException - If an I/O error occurs

NoSuchDeviceException

Button

public Button(GpioDeviceFactoryInterface deviceFactory,
PinInfo pinInfo,
GpioPullUpDown pud,
GpioEventTrigger trigger,
boolean activeHigh)
       throws RuntimeIOException,
NoSuchDeviceException

Parameters:

deviceFactory - Device factory to use to provision this digital input device

pinInfo - Information about the GPIO pin to which the device is connected

pud - Pull up/down configuration, values: NONE, PULL_UP, PULL_DOWN

trigger - Event trigger configuration, values: NONE, RISING, FALLING, BOTH

activeHigh - Set to true if digital 1 is to be treated as active

Throws:

RuntimeIOException - If an I/O error occurs.

NoSuchDeviceException

Method Details

isPressed

public boolean isPressed()

Get the current state.

Returns:

Return true if the button is currently pressed.

isReleased

public boolean isReleased()

Get the current state.

Returns:

Return true if the button is currently released.

whenPressed

public void whenPressed(LongConsumer consumer)

Action to perform when the button is pressed.

Parameters:

consumer - Callback function to invoke when pressed (long parameter is nanoseconds time).

whenReleased

public void whenReleased(LongConsumer consumer)

Action to perform when the button is released.

Parameters:

consumer - Callback function to invoke when pressed (long parameter is nanoseconds time).