fm.h

/*
 * fm.h
 * A library for SeeedStudio seeeduino GPRS shield 
 *
 * Copyright (c) 2013 seeed technology inc.
 * Author        :   lawliet zou
 * Create Time   :   Dec 2013
 * Change Log    :
 *
 * The MIT License (MIT)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 
#ifndef __FM_H__
#define __FM_H__

#include "sim800.h"

/** FM class.
 *  used to use FM function
 */
class FM: public SIM800
{

public:
    FM(int baudRate = 19200) : SIM800(baudRate){
        fmChannelCount = 0;
        fmCurrentChannel = 0;
    };
    
    /** power on FM module
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int powerOn(void);
    
    /** power off FM module
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int powerOff(void);
    
    /** set radio frequency
     *  @param  freq    freq that will be chosen
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int setFreq(int freq);
    
    /** set volume of FM output
     *  @param  volume  volume:0/1/2/3/4/5/6
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int setVolume(int volume);
    
    /** search for channel
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int scanChannel(void);
    
    /** check channel's signal strength
     *  @param  channelFreq the channel that will be checked
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int checkSignalStrength(int channelFreq);
    
    /** jump to next channel
     *  @returns
     *      0 on success
     *      -1 on error
     */
    int channelNext(void);
    
private:
    /** FM power flag
     */
    bool fmPower;
    
    /** channel array to save valid channel
     */
    int fmChannel[10];
    
    /** FM valid channel count record
     */
    int fmChannelCount;
    
    /** current channel index
     */
    int fmCurrentChannel;
};
#endif