Si4735.h

00001 /* mbed Si4735 Library
00002  * Brett Wilson and Brett Berry
00003  * Georgia Tech ECE 4180
00004  * Ported from ...
00005 
00006  * Arduino Si4735 Library
00007  * Written by Ryan Owens for SparkFun Electronics
00008  * 5/17/11
00009  *
00010  * This library is for use with the SparkFun Si4735 Shield
00011  * Released under the 'Buy Me a Beer' license
00012  * (If we ever meet, you buy me a beer)
00013  *
00014  * See the example sketches to learn how to use the library in your code.
00015 */
00016 
00017 #include "mbed.h"
00018 
00019 #ifndef Si4735_h
00020 #define Si4735_h
00021 
00022 //Assign the radio pin numbers
00023 #define POWER_PIN    8
00024 #define    RADIO_RESET_PIN    9
00025 #define INT_PIN    2
00026 
00027 //Define the SPI Pin Numbers
00028 #define DATAOUT 11        //MOSI
00029 #define DATAIN  12        //MISO 
00030 #define SPICLOCK  13    //sck
00031 #define SS 10            //ss
00032 
00033 //List of possible modes for the Si4735 Radio
00034 #define AM    0
00035 #define    FM    1
00036 #define SW    2
00037 #define    LW    3
00038 
00039 #define ON    true
00040 #define OFF    false
00041 
00042 #define address_write 34
00043 #define address_read 35
00044 
00045 class Si4735
00046 {
00047     public:
00048         //This is just a constructor.
00049         Si4735(PinName sda, PinName scl, PinName RST_);
00050         /*
00051         * Description: 
00052         *    Initializes the Si4735, powers up the radio in the desired mode and limits the bandwidth appropriately.
00053         *     This function must be called before any other radio command.
00054         *    The bands are set as follows:
00055         *    FM - 87.5 - 107.9 MHz
00056         *    AM - 520 - 1710 kHz
00057         *    SW - 2300 - 23000 khz
00058         *    LW - 152 - 279 kHz
00059         * Parameters:
00060         *    mode - The desired radio mode. Use AM(0), FM(1), SW(2) or LW(3).
00061         */
00062         void begin(char mode);
00063         /*
00064         * Description: 
00065         *    Used to send an ascii command string to the radio.
00066         * Parameters:
00067         *    myCommand - A null terminated ascii string limited to hexidecimal characters
00068         *                to be sent to the radio module. Instructions for building commands can be found
00069         *                in the Si4735 Programmers Guide.
00070         */
00071         void sendCommand(char * myCommand);
00072         /*
00073         * Description: 
00074         *    Used to to tune the radio to a desired frequency. The library uses the mode indicated in the
00075         *     begin() function to determine how to set the frequency.
00076         * Parameters:
00077         *    frequency - The frequency to tune to, in kHz (or in 10kHz if using FM mode).
00078         * Returns:
00079         *    True
00080         * TODO:
00081         *     Make the function return true if the tune was successful, else return false.
00082         */
00083         bool tuneFrequency(int frequency);
00084         /*
00085         * Description:
00086         *    This function currently does not work!
00087         * TODO:
00088         *    Make this function work.
00089         */
00090         int getFrequency(void);
00091         /*
00092         * Description:
00093         *    Commands the radio to seek up to the next valid channel. If the top of the band is reached, the seek
00094         *    will continue from the bottom of the band.
00095         * Returns:
00096         *    True
00097         * TODO:
00098         *    Make the function return true if a valid channel was found, else return false.
00099         */
00100         bool seekUp(void);
00101         /*
00102         * Description:
00103         *    Commands the radio to seek down to the next valid channel. If the bottom of the band is reached, the seek
00104         *    will continue from the top of the band.
00105         * Returns:
00106         *    True
00107         * TODO:
00108         *    Make the function return true if a valid channel was found, else return false.
00109         */        
00110         bool seekDown(void);
00111         /*
00112         * Description:
00113         *    Increasese the volume by 1. If the maximum volume has been reached, no increase will take place.
00114         */
00115         void volumeUp(void);
00116         /*
00117         * Description:
00118         *    Decreases the volume by 1. If the minimum volume has been reached, no decrease will take place.
00119         */
00120         void volumeDown(void);
00121         /*
00122         * Description:
00123         *    Mutes the audio output
00124         */
00125         void mute(void);
00126         /*
00127         * Description:
00128         *    Disables the mute.
00129         */
00130         void unmute(void);
00131         /*
00132         * Description:
00133         *    Gets the current status of the radio. Learn more about the status in the Si4735 datasheet.
00134         * Returns:
00135         *    The status of the radio.
00136         */
00137         char getStatus(void);
00138         /*
00139         * Description:
00140         *    Gets the long response (16 characters) from the radio. Learn more about the long response in the Si4735 datasheet.
00141         * Parameters:
00142         *    response - A string for the response from the radio to be stored in.
00143         */
00144         void getResponse(char * response);
00145         /*
00146         * Description:
00147         *    Powers down the radio
00148         */
00149         void end(void);
00150         
00151     private:
00152         // Pointer for the SPI bus
00153         I2C* i2c_;
00154         // Declare digital out pins
00155         DigitalOut _RST_;
00156         /*
00157         * A variable that is assigned the current mode of the radio (AM, FM, SW or LW)
00158         */
00159         char _mode;
00160         /*
00161         * A variable the keeps the current volume level. 
00162         */
00163         char _currentVolume;
00164         /*
00165         * Command string that holds the binary command string to be sent to the Si4735.
00166         */
00167         char command[9];
00168         /*
00169         * Description:
00170         *    Sends a binary command string to the Si4735.
00171         * Parameters:
00172         *    command - Binary command to be sent to the radio.
00173         *    length - The number of characters in the command string (since it can't be null terminated!)
00174         * TODO:
00175         *    Make the command wait for a valid CTS response from the radio before releasing control of the CPU.
00176         */
00177         void sendCommand(char * command, int length);
00178         /*
00179         * Description:
00180         *    Sends/Receives a character from the SPI bus.
00181         * Parameters:
00182         *    value - The character to be sent to the SPI bus.
00183         * Returns:
00184         *    The character read from the SPI bus during the transfer.
00185         */
00186         char spiTransfer(char value);
00187         
00188 };
00189 
00190 #endif