com.pi4j.component.sensor.impl.GpioMotionSensorComponent Maven / Gradle / Ivy

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package com.pi4j.component.sensor.impl;

/*
 * #%L
 * **********************************************************************
 * ORGANIZATION  :  Pi4J
 * PROJECT       :  Pi4J :: Device Abstractions
 * FILENAME      :  GpioMotionSensorComponent.java  
 * 
 * This file is part of the Pi4J project. More information about 
 * this project can be found here:  http://www.pi4j.com/
 * **********************************************************************
 * %%
 * Copyright (C) 2012 - 2015 Pi4J
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * .
 * #L%
 */


import com.pi4j.component.sensor.MotionSensor;
import com.pi4j.component.sensor.MotionSensorBase;
import com.pi4j.component.sensor.MotionSensorChangeEvent;
import com.pi4j.io.gpio.GpioPinDigitalInput;
import com.pi4j.io.gpio.PinState;
import com.pi4j.io.gpio.event.GpioPinDigitalStateChangeEvent;
import com.pi4j.io.gpio.event.GpioPinListenerDigital;

public class GpioMotionSensorComponent extends MotionSensorBase {
    
    // internal class members
    private GpioPinDigitalInput pin = null;
    private PinState motionDetectedState = PinState.HIGH;
    private final MotionSensor sensor = this;
    
    // create internal pin listener
    private GpioPinListenerDigital pinListener = new GpioPinListenerDigital() {

        @Override
        public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {            
            // notify any motion sensor change listeners
            notifyListeners(new MotionSensorChangeEvent(sensor, (event.getState() == motionDetectedState)));                
        }
    };
    
    /**
     * using this constructor requires that the consumer 
     *  define the MOTION DETECTED pin state 
     *  
     * @param pin GPIO digital input pin
     * @param motionDetectedState pin state to set when SENSOR DETECTS MOTION
     */
    public GpioMotionSensorComponent(GpioPinDigitalInput pin, PinState motionDetectedState) {
        this.pin = pin;
        this.motionDetectedState = motionDetectedState;
        
        // add pin listener
        this.pin.addListener(pinListener);
    }

    /**
     * default constructor; using this constructor assumes that:
     *  (1) a pin state of HIGH is MOTION DETECTED
     *  
     * @param pin GPIO digital input pin
     */
    public GpioMotionSensorComponent(GpioPinDigitalInput pin) {
        this.pin = pin;
        
        // add pin listener
        this.pin.addListener(pinListener); 
    }

    /**
     * Return 'true' if motion is currently detected   
     * based on the GPIO digital input pin state.
     *  
     * @return motion detected status 
     */
    @Override
    public boolean isMotionDetected() {
        return pin.isState(motionDetectedState);
    }
}