Java GpioPinDigitalInput.addTrigger方法代码示例

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {

        System.out.println("<--Pi4J--> GPIO Blink Trigger Example ... started.");

        // create gpio controller
        final GpioController gpio = GpioFactory.getInstance();

        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02,
                                                  PinPullResistance.PULL_DOWN);

        System.out.println(" ... complete the GPIO #02 circuit and see the blink trigger take effect.");

        // setup gpio pins #04 an output pins and make sure they are all LOW at startup
        final GpioPinDigitalOutput myLed = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, PinState.LOW);

        // create a gpio control trigger on the input pin ; when the input goes HIGH, turn on blinking
        myButton.addTrigger(new GpioBlinkStateTrigger(PinState.HIGH, myLed, 250));

        // create a gpio control trigger on the input pin ; when the input goes LOW, turn off blinking
        myButton.addTrigger(new GpioBlinkStopStateTrigger(PinState.LOW, myLed));

        // keep program running until user aborts (CTRL-C)
        while(true) {
            Thread.sleep(500);
        }

        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller
    }
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {
    
    System.out.println("<--Pi4J--> GPIO Blink Trigger Example ... started.");

    // create gpio controller
    final GpioController gpio = GpioFactory.getInstance();

    // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
    final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02, 
                                              PinPullResistance.PULL_DOWN);
    
    System.out.println(" ... complete the GPIO #02 circuit and see the blink trigger take effect.");
    
    // setup gpio pins #04 an output pins and make sure they are all LOW at startup
    final GpioPinDigitalOutput myLed = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, PinState.LOW);
    
    // create a gpio control trigger on the input pin ; when the input goes HIGH, turn on blinking
    myButton.addTrigger(new GpioBlinkStateTrigger(PinState.HIGH, myLed, 250));

    // create a gpio control trigger on the input pin ; when the input goes LOW, turn off blinking
    myButton.addTrigger(new GpioBlinkStopStateTrigger(PinState.LOW, myLed));

    // keep program running until user aborts (CTRL-C)
    for (;;) {
        Thread.sleep(500);
    }
    
    // stop all GPIO activity/threads by shutting down the GPIO controller
    // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
    // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller        
}
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {

        // START SNIPPET: usage-create-controller-snippet
        // create gpio controller instance
        final GpioController gpio = GpioFactory.getInstance();
        // END SNIPPET: usage-create-controller-snippet

        // START SNIPPET: usage-provision-input-pin-snippet
        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        // (configure pin edge to both rising and falling to get notified for HIGH and LOW state
        // changes)
        GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02,             // PIN NUMBER
                                                                     "MyButton",                   // PIN FRIENDLY NAME (optional)
                                                                     PinPullResistance.PULL_DOWN); // PIN RESISTANCE (optional)

        // END SNIPPET: usage-provision-input-pin-snippet
        // START SNIPPET: usage-provision-output-pin-snippet
        // provision gpio pins #04 as an output pin and make sure is is set to LOW at startup
        GpioPinDigitalOutput myLed = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04,   // PIN NUMBER
                                                                   "My LED",           // PIN FRIENDLY NAME (optional)
                                                                   PinState.LOW);      // PIN STARTUP STATE (optional)
        // END SNIPPET: usage-provision-output-pin-snippet

        // START SNIPPET: usage-shutdown-pin-snippet
        // configure the pin shutdown behavior; these settings will be
        // automatically applied to the pin when the application is terminated
        // ensure that the LED is turned OFF when the application is shutdown
        myLed.setShutdownOptions(true, PinState.LOW, PinPullResistance.OFF);
        // END SNIPPET: usage-shutdown-pin-snippet

        // START SNIPPET: usage-control-pin-snippet
        // explicitly set a state on the pin object
        myLed.setState(PinState.HIGH);

        // use convenience wrapper method to set state on the pin object
        myLed.low();
        myLed.high();

        // use toggle method to apply inverse state on the pin object
        myLed.toggle();

        // use pulse method to set the pin to the HIGH state for
        // an explicit length of time in milliseconds
        myLed.pulse(1000);
        // END SNIPPET: usage-control-pin-snippet

        // START SNIPPET: usage-read-pin-snippet
        // get explicit state enumeration for the GPIO pin associated with the button
        PinState myButtonState = myButton.getState();

        // use convenience wrapper method to interrogate the button state
        boolean buttonPressed = myButton.isHigh();
        // END SNIPPET: usage-read-pin-snippet

        // START SNIPPET: usage-register-listener-snippet
        // create and register gpio pin listener
        myButton.addListener(new GpioUsageExampleListener());
        // END SNIPPET: usage-register-listener-snippet

        // START SNIPPET: usage-trigger-snippet
        // create a gpio synchronization trigger on the input pin
        // when the input state changes, also set LED controlling gpio pin to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myLed));
        // END SNIPPET: usage-trigger-snippet

        // keep program running until user aborts (CTRL-C)
        while (true) {
            Thread.sleep(500);
        }

        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller
    }
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String args[]) throws InterruptedException, IOException {

        System.out.println("<--Pi4J--> GPIO Listen Example ... started.");

        // create gpio controller
        final GpioController gpio = GpioFactory.getInstance();

        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02, PinPullResistance.PULL_DOWN);

        // create custom Olimex GPIO provider
        final OlimexAVRIOGpioProvider olimexProvider = new OlimexAVRIOGpioProvider(Serial.DEFAULT_COM_PORT);

        // provision gpio input pin #01 from Olimex
        final GpioPinDigitalInput myInput = gpio.provisionDigitalInputPin(olimexProvider, OlimexAVRIOPin.IN_01);

        // create gpio pin listener
        GpioPinListenerDigital listener = new GpioPinListenerDigital() {
            @Override
            public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {
                // display pin state on console
                System.out.println(" --> GPIO PIN STATE CHANGE: " + event.getPin() + " = "
                        + event.getState());
            }
        };

        // register gpio pin listener for each input pin
        myButton.addListener(listener);
        myInput.addListener(listener);

        // setup gpio pins #04, #05, #06 as an output pins and make sure they are all LOW at startup
        GpioPinDigitalOutput myRelays[] = {
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_01, "RELAY #1", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_02, "RELAY #2", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_03, "RELAY #3", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_04, "RELAY #4", PinState.LOW)
          };

        // create a gpio control trigger on the input pin ; when the input goes HIGH, also set gpio pin #04 to HIGH
        myButton.addTrigger(new GpioSetStateTrigger(PinState.HIGH, myRelays[0], PinState.HIGH));

        // create a gpio control trigger on the input pin ; when the input goes LOW, also set gpio pin #04 to LOW
        myButton.addTrigger(new GpioSetStateTrigger(PinState.LOW, myRelays[0], PinState.LOW));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myRelays[1]));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myRelays[2]));

        // create a gpio pulse trigger on the input pin; when the input goes HIGH, also pulse gpio pin #06 to the HIGH state for 1 second
        myButton.addTrigger(new GpioPulseStateTrigger(PinState.HIGH, myRelays[3], 1000));

        System.out.println(" ... complete the GPIO #02 circuit and see the listener feedback here in the console.");

        // keep program running until user aborts (CTRL-C)
        // or we reach 60 seconds
        Thread.sleep(60000);

        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        gpio.shutdown();

        System.out.println("Exiting OlimexGpioExample");
    }
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {

        System.out.println("<--Pi4J--> GPIO Trigger Example ... started.");

        // create gpio controller
        final GpioController gpio = GpioFactory.getInstance();

        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02,
                                                  PinPullResistance.PULL_DOWN);

        System.out.println(" ... complete the GPIO #02 circuit and see the triggers take effect.");

        // setup gpio pins #04, #05, #06 as an output pins and make sure they are all LOW at startup
        GpioPinDigitalOutput myLed[] = {
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, "LED #1", PinState.LOW),
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_05, "LED #2", PinState.LOW),
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_06, "LED #3", PinState.LOW)
          };

        // create a gpio control trigger on the input pin ; when the input goes HIGH, also set gpio pin #04 to HIGH
        myButton.addTrigger(new GpioSetStateTrigger(PinState.HIGH, myLed[0], PinState.HIGH));

        // create a gpio control trigger on the input pin ; when the input goes LOW, also set gpio pin #04 to LOW
        myButton.addTrigger(new GpioSetStateTrigger(PinState.LOW, myLed[0], PinState.LOW));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myLed[1]));

        // create a gpio pulse trigger on the input pin; when the input goes HIGH, also pulse gpio pin #06 to the HIGH state for 1 second
        myButton.addTrigger(new GpioPulseStateTrigger(PinState.HIGH, myLed[2], 1000));

        // create a gpio callback trigger on gpio pin#4; when #4 changes state, perform a callback
        // invocation on the user defined 'Callable' class instance
        myButton.addTrigger(new GpioCallbackTrigger(new Callable<Void>() {
            public Void call() throws Exception {
                System.out.println(" --> GPIO TRIGGER CALLBACK RECEIVED ");
                return null;
            }
        }));

        // keep program running until user aborts (CTRL-C)
        while (true) {
            Thread.sleep(500);
        }

        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller
    }
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {
    
    // START SNIPPET: usage-create-controller-snippet
    // create gpio controller instance
    final GpioController gpio = GpioFactory.getInstance();
    // END SNIPPET: usage-create-controller-snippet

    // START SNIPPET: usage-provision-input-pin-snippet
    // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
    // (configure pin edge to both rising and falling to get notified for HIGH and LOW state
    // changes)
    GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02,             // PIN NUMBER
                                                                 "MyButton",                   // PIN FRIENDLY NAME (optional)
                                                                 PinPullResistance.PULL_DOWN); // PIN RESISTANCE (optional)

    // END SNIPPET: usage-provision-input-pin-snippet
    // START SNIPPET: usage-provision-output-pin-snippet
    // provision gpio pins #04 as an output pin and make sure is is set to LOW at startup
    GpioPinDigitalOutput myLed = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04,   // PIN NUMBER
                                                               "My LED",           // PIN FRIENDLY NAME (optional)
                                                               PinState.LOW);      // PIN STARTUP STATE (optional)
    // END SNIPPET: usage-provision-output-pin-snippet

    // START SNIPPET: usage-shutdown-pin-snippet
    // configure the pin shutdown behavior; these settings will be 
    // automatically applied to the pin when the application is terminated
    // ensure that the LED is turned OFF when the application is shutdown
    myLed.setShutdownOptions(true, PinState.LOW, PinPullResistance.OFF);
    // END SNIPPET: usage-shutdown-pin-snippet
    
    // START SNIPPET: usage-control-pin-snippet
    // explicitly set a state on the pin object
    myLed.setState(PinState.HIGH);

    // use convenience wrapper method to set state on the pin object
    myLed.low();
    myLed.high();

    // use toggle method to apply inverse state on the pin object
    myLed.toggle();

    // use pulse method to set the pin to the HIGH state for
    // an explicit length of time in milliseconds
    myLed.pulse(1000);
    // END SNIPPET: usage-control-pin-snippet

    // START SNIPPET: usage-read-pin-snippet
    // get explicit state enumeration for the GPIO pin associated with the button
    PinState myButtonState = myButton.getState();

    // use convenience wrapper method to interrogate the button state
    boolean buttonPressed = myButton.isHigh();
    // END SNIPPET: usage-read-pin-snippet

    // START SNIPPET: usage-register-listener-snippet
    // create and register gpio pin listener
    myButton.addListener(new GpioUsageExampleListener());
    // END SNIPPET: usage-register-listener-snippet

    // START SNIPPET: usage-trigger-snippet
    // create a gpio synchronization trigger on the input pin
    // when the input state changes, also set LED controlling gpio pin to same state
    myButton.addTrigger(new GpioSyncStateTrigger(myLed));
    // END SNIPPET: usage-trigger-snippet

    // keep program running until user aborts (CTRL-C)
    for (;;) {
        Thread.sleep(500);
    }
    
    // stop all GPIO activity/threads by shutting down the GPIO controller
    // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
    // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller                
}
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String args[]) throws InterruptedException {

        System.out.println("<--Pi4J--> GPIO Listen Example ... started.");
        
        // create gpio controller
        final GpioController gpio = GpioFactory.getInstance();
        
        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02, PinPullResistance.PULL_DOWN);

        // create custom Olimex GPIO provider
        final OlimexAVRIOGpioProvider olimexProvider = new OlimexAVRIOGpioProvider(Serial.DEFAULT_COM_PORT);
        
        // provision gpio input pin #01 from Olimex
        final GpioPinDigitalInput myInput = gpio.provisionDigitalInputPin(olimexProvider, OlimexAVRIOPin.IN_01);
        
        // create gpio pin listener
        GpioPinListenerDigital listener = new GpioPinListenerDigital() {            
            @Override
            public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {
                // display pin state on console
                System.out.println(" --> GPIO PIN STATE CHANGE: " + event.getPin() + " = "
                        + event.getState());
            }
        };
        
        // register gpio pin listener for each input pin 
        myButton.addListener(listener);
        myInput.addListener(listener);
        
        // setup gpio pins #04, #05, #06 as an output pins and make sure they are all LOW at startup
        GpioPinDigitalOutput myRelays[] = { 
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_01, "RELAY #1", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_02, "RELAY #2", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_03, "RELAY #3", PinState.LOW),
            gpio.provisionDigitalOutputPin(olimexProvider, OlimexAVRIOPin.RELAY_04, "RELAY #4", PinState.LOW)
          };
        
        // create a gpio control trigger on the input pin ; when the input goes HIGH, also set gpio pin #04 to HIGH
        myButton.addTrigger(new GpioSetStateTrigger(PinState.HIGH, myRelays[0], PinState.HIGH));

        // create a gpio control trigger on the input pin ; when the input goes LOW, also set gpio pin #04 to LOW
        myButton.addTrigger(new GpioSetStateTrigger(PinState.LOW, myRelays[0], PinState.LOW));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myRelays[1]));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myRelays[2]));
        
        // create a gpio pulse trigger on the input pin; when the input goes HIGH, also pulse gpio pin #06 to the HIGH state for 1 second
        myButton.addTrigger(new GpioPulseStateTrigger(PinState.HIGH, myRelays[3], 1000));

        System.out.println(" ... complete the GPIO #02 circuit and see the listener feedback here in the console.");
        
        // keep program running until user aborts (CTRL-C)
        // or we reach 60 seconds
        for (int seconds = 0; seconds < 60; seconds++) {
            Thread.sleep(1000);
        }
        
        System.out.println(" ... exiting program.");
        
        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        gpio.shutdown();                 
    }
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {
    
    System.out.println("<--Pi4J--> GPIO Trigger Example ... started.");

    // create gpio controller
    final GpioController gpio = GpioFactory.getInstance();

    // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
    final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02, 
                                              PinPullResistance.PULL_DOWN);
    
    System.out.println(" ... complete the GPIO #02 circuit and see the triggers take effect.");
    
    // setup gpio pins #04, #05, #06 as an output pins and make sure they are all LOW at startup
    GpioPinDigitalOutput myLed[] = { 
        gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, "LED #1", PinState.LOW),
        gpio.provisionDigitalOutputPin(RaspiPin.GPIO_05, "LED #2", PinState.LOW),
        gpio.provisionDigitalOutputPin(RaspiPin.GPIO_06, "LED #3", PinState.LOW) 
      };
    
    // create a gpio control trigger on the input pin ; when the input goes HIGH, also set gpio pin #04 to HIGH
    myButton.addTrigger(new GpioSetStateTrigger(PinState.HIGH, myLed[0], PinState.HIGH));

    // create a gpio control trigger on the input pin ; when the input goes LOW, also set gpio pin #04 to LOW
    myButton.addTrigger(new GpioSetStateTrigger(PinState.LOW, myLed[0], PinState.LOW));

    // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
    myButton.addTrigger(new GpioSyncStateTrigger(myLed[1]));

    // create a gpio pulse trigger on the input pin; when the input goes HIGH, also pulse gpio pin #06 to the HIGH state for 1 second
    myButton.addTrigger(new GpioPulseStateTrigger(PinState.HIGH, myLed[2], 1000));

    // create a gpio callback trigger on gpio pin#4; when #4 changes state, perform a callback
    // invocation on the user defined 'Callable' class instance
    myButton.addTrigger(new GpioCallbackTrigger(new Callable<Void>() {
        public Void call() throws Exception {
            System.out.println(" --> GPIO TRIGGER CALLBACK RECEIVED ");
            return null;
        }
    }));

    // keep program running until user aborts (CTRL-C)
    for (;;) {
        Thread.sleep(500);
    }

    // stop all GPIO activity/threads by shutting down the GPIO controller
    // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
    // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller        
}
 

import com.pi4j.io.gpio.GpioPinDigitalInput; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {

        System.out.println("<--Pi4J--> GPIO Trigger Example ... started.");

        // create gpio controller
        final GpioController gpio = GpioFactory.getInstance();

        // provision gpio pin #02 as an input pin with its internal pull down resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_02,
                                                  PinPullResistance.PULL_DOWN);

        System.out.println(" ... complete the GPIO #02 circuit and see the triggers take effect.");

        // setup gpio pins #04, #05, #06 as an output pins and make sure they are all LOW at startup
        GpioPinDigitalOutput myLed[] = {
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, "LED #1", PinState.LOW),
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_05, "LED #2", PinState.LOW),
            gpio.provisionDigitalOutputPin(RaspiPin.GPIO_06, "LED #3", PinState.LOW)
          };

        // create a gpio control trigger on the input pin ; when the input goes HIGH, also set gpio pin #04 to HIGH
        myButton.addTrigger(new GpioSetStateTrigger(PinState.HIGH, myLed[0], PinState.HIGH));

        // create a gpio control trigger on the input pin ; when the input goes LOW, also set gpio pin #04 to LOW
        myButton.addTrigger(new GpioSetStateTrigger(PinState.LOW, myLed[0], PinState.LOW));

        // create a gpio synchronization trigger on the input pin; when the input changes, also set gpio pin #05 to same state
        myButton.addTrigger(new GpioSyncStateTrigger(myLed[1]));

        // create a gpio pulse trigger on the input pin; when the input goes HIGH, also pulse gpio pin #06 to the HIGH state for 1 second
        myButton.addTrigger(new GpioPulseStateTrigger(PinState.HIGH, myLed[2], 1000));

        // create a gpio callback trigger on gpio pin#4; when #4 changes state, perform a callback
        // invocation on the user defined 'Callable' class instance
        myButton.addTrigger(new GpioCallbackTrigger(new Callable<Void>() {
            public Void call() throws Exception {
                System.out.println(" --> GPIO TRIGGER CALLBACK RECEIVED ");
                return null;
            }
        }));

        // keep program running until user aborts (CTRL-C)
        for (;;) {
            Thread.sleep(500);
        }

        // stop all GPIO activity/threads by shutting down the GPIO controller
        // (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
        // gpio.shutdown();   <--- implement this method call if you wish to terminate the Pi4J GPIO controller
    }