package com.pi4j.component.sensor.impl;
/*
* #%L
* **********************************************************************
* ORGANIZATION : Pi4J
* PROJECT : Pi4J :: Device Abstractions
* FILENAME : GpioSensorComponent.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 - 2013 Pi4J
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
import com.pi4j.component.sensor.Sensor;
import com.pi4j.component.sensor.SensorBase;
import com.pi4j.component.sensor.SensorState;
import com.pi4j.component.sensor.SensorStateChangeEvent;
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 GpioSensorComponent extends SensorBase {
// internal class members
private GpioPinDigitalInput pin = null;
private PinState openState = PinState.LOW;
private PinState closedState = PinState.HIGH;
private final Sensor sensor = this;
// create internal pin listener
private GpioPinListenerDigital pinListener = new GpioPinListenerDigital() {
@Override
public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {
// notify any sensor state change listeners
if(event.getState() == openState) {
notifyListeners(new SensorStateChangeEvent(sensor, SensorState.CLOSED, SensorState.OPEN));
}
else if(event.getState() == closedState) {
notifyListeners(new SensorStateChangeEvent(sensor, SensorState.CLOSED, SensorState.OPEN));
}
}
};
/**
* using this constructor requires that the consumer
* define the SENSOR OPEN and SENSOR CLOSED pin states
*
* @param pin GPIO digital input pin
* @param openState pin state to set when SENSOR is OPEN
* @param closedState pin state to set when SENSOR is CLOSED
*/
public GpioSensorComponent(GpioPinDigitalInput pin, PinState openState, PinState closedState) {
this.pin = pin;
this.openState = openState;
this.closedState = closedState;
// add pin listener
this.pin.addListener(pinListener);
}
/**
* default constructor; using this constructor assumes that:
* (1) a pin state of HIGH is SENSOR CLOSED
* (2) a pin state of LOW is SENSOR OPEN
*
* @param pin GPIO digital input pin
*/
public GpioSensorComponent(GpioPinDigitalInput pin) {
this.pin = pin;
// add pin listener
this.pin.addListener(pinListener);
}
/**
* Return the current sensor state based on the
* GPIO digital output pin state.
*
* @return PowerState
*/
@Override
public SensorState getState() {
if(pin.isState(openState))
return SensorState.OPEN;
else
return SensorState.CLOSED;
}
}