/*******************************************************************************
 * Copyright (c) 2016 Julien Louette & Gaël Wittorski
 * 
 * This file is part of Raspoid.
 * 
 * Raspoid 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.
 * 
 * Raspoid 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with Raspoid.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package com.raspoid.additionalcomponents;

import com.raspoid.AnalogComponent;
import com.raspoid.additionalcomponents.adc.ADC;
import com.raspoid.additionalcomponents.adc.ADCChannel;
import com.raspoid.examples.additionalcomponents.PhotoresistorExample;

/**
 * A photoresistor is a light-controlled variable resistor. The resistance of a 
 * photoresistor decreases with increasing incident light intensity.
 * 
 * <p>Unlike infrared detectors, photocells are good at detecting yellow/green visible light,
 * but not infrared light.</p>
 * 
 * <p>This component uses an ADC (Anolog to Digital Converter) to transform the analog 
 * signal generated by the photoresistor variations.</p>
 * 
 * <p>Example Datasheet: <a href="http://raspoid.com/download/datasheet/Photoresistor">Photoresistor</a></p>
 * 
 * <p>Example of use: {@link PhotoresistorExample}</p>
 * 
 * @see ADC
 * 
 * @author Julien Louette &amp; Ga&euml;l Wittorski
 * @version 1.0
 */
public class Photoresistor extends AnalogComponent {
    
    private ADCChannel photoresistorChannel;
    
    /**
     * Constructor for a photoresistor using a specific ADC instance, and a specific
     * channel on this ADC to decode the analog input from the photoresistor.
     * @param adc the ADC to use to decode analogic signals from the photoresistor.
     * @param photoresistorChannel the channel on the ADC used to read inputs from the photoresistor.
     */
    public Photoresistor(ADC adc, ADCChannel photoresistorChannel) {
        super(adc);
        this.photoresistorChannel = photoresistorChannel;
    }
    
    /**
     * Get the light intensity read from the photoresistor. 
     * @return the light intensity read from the photoresistor.
     */
    public int getIntensity() {
        return adc.analogToDigital(photoresistorChannel);
    }
}