Si4735 Library for Arduino

/*****************************************************************
 * SI473X data types 
 * These data types will be usefull to deal with SI473X 
 *****************************************************************/

/*
 * Power Up arguments data type 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 64 and 65
 */
    typedef union {
    struct
    {
        // ARG1
        byte FUNC : 4;    // Function (0 = FM Receive; 1–14 = Reserved; 15 = Query Library ID)
        byte XOSCEN : 1;  // Crystal Oscillator Enable (0 = crystal oscillator disabled; 1 = Use crystal oscillator and and OPMODE=ANALOG AUDIO) .
        byte PATCH : 1;   // Patch Enable (0 = Boot normally; 1 = Copy non-volatile memory to RAM).
        byte GPO2OEN : 1; // GPO2 Output Enable (0 = GPO2 output disabled; 1 = GPO2 output enabled).
        byte CTSIEN : 1;  // CTS Interrupt Enable (0 = CTS interrupt disabled; 1 = CTS interrupt enabled).
        // ARG2
        byte OPMODE; // Application Setting. See page 65
    } arg;
    byte raw[2]; // same arg memory position, so same content.
} si473x_powerup;

/*
 * Represents how the  frequency is stored in the si4735.
 * It helps to convert frequency in unsigned int to two bytes (FREQL and FREQH)  
 */
typedef union {
    struct
    {
        byte FREQL; // Tune Frequency High Byte.
        byte FREQH; // Tune Frequency Low Byte.
    } raw;
    unsigned value;
} si47x_frequency;

/* 
 *  Represents searching for a valid frequency data type.
 */
typedef union {
    struct
    {
        byte RESERVED1 : 2;
        byte WRAP : 1;   // Determines whether the seek should Wrap = 1, or Halt = 0 when it hits the band limit.
        byte SEEKUP : 1; // Determines the direction of the search, either UP = 1, or DOWN = 0.
        byte RESERVED2 : 4;
    } arg;
    byte raw;
} si47x_seek;

/*  
 * Response status command 
 * See Si47XX PROGRAMMING GUIDE; pages 73 and 
 */
typedef union {
    struct
    {
        // Status
        byte STCINT : 1; // Seek/Tune Complete Interrupt; 1 = Tune complete has been triggered.
        byte DUMMY1 : 1;
        byte RDSINT : 1; // Radio Data System (RDS) Interrup; 0 = interrupt has not been triggered.
        byte RSQINT : 1; // Received Signal Quality Interrupt; 0 = interrupt has not been triggered.
        byte DUMMY2 : 2;
        byte ERR : 1; // Error. 0 = No error 1 = Error
        byte CTS : 1; // Clear to Send.
        // RESP1
        byte VALID : 1; // Valid Channel
        byte AFCRL : 1; // AFC Rail Indicator
        byte DUMMY3 : 5;
        byte BLTF : 1; // Reports if a seek hit the band limit
        // RESP2
        byte READFREQH; // Read Frequency High Byte.
        // RESP3
        byte READFREQL; // Read Frequency Low Byte.
        // RESP4
        byte RSSI; // Received Signal Strength Indicator (dBμV)
        // RESP5
        byte SNR; // This byte contains the SNR metric when tune is complete (dB).
        // RESP6
        byte MULT; // Contains the multipath metric when tune is complete
        // RESP7
        byte READANTCAP; // Contains the current antenna tuning capacitor value
    } resp;
    byte raw[7];
} si47x_response_status;

/*
 * Firmware Information
 */
typedef union {
    struct
    {
        // status ("RESP0")
        byte STCINT : 1;
        byte DUMMY1 : 1;
        byte RDSINT : 1;
        byte RSQINT : 1;
        byte DUMMY2 : 2;
        byte ERR : 1;
        byte CTS : 1;
        byte PN;       //  RESP1 - Final 2 digits of Part Number (HEX).
        byte FWMAJOR;  // RESP2 - Firmware Major Revision (ASCII).
        byte FWMINOR;  // RESP3 - Firmware Minor Revision (ASCII).
        byte PATCHH;   // RESP4 - Patch ID High Byte (HEX).
        byte PATCHL;   // RESP5 - Patch ID Low Byte (HEX).
        byte CMPMAJOR; // RESP6 - Component Major Revision (ASCII).
        byte CMPMINOR; // RESP7 - Component Minor Revision (ASCII).
        byte CHIPREV;  // RESP8 - Chip Revision (ASCII).
        // RESP9 to RESP15 not used
    } resp;
    byte raw[9];
} si47x_firmware_information;

/*
 * Status of FM_TUNE_FREQ or FM_SEEK_START commands or 
 * Status of AM_TUNE_FREQ or AM_SEEK_START commands.
 * 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 73 and 139
 */
typedef union {
    struct
    {
        byte INTACK : 1; // If set, clears the seek/tune complete interrupt status indicator.
        byte CANCEL : 1; // If set, aborts a seek currently in progress.
        byte RESERVED2 : 6;
    } arg;
    byte raw;
} si47x_tune_status;

/*
 * Property Data type (help to deal with SET_PROPERTY command on si473X)
 */
typedef union {
    struct
    {
        byte byteLow;
        byte byteHigh;
    } raw;
    unsigned value;
} si47x_property;

/*
 ********************** RDS Data types *******************************
 */

/* 
 * Data type for status information about the received signal quality
 * FM_RSQ_STATUS and AM_RSQ_STATUS
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 75 and 
 */
typedef union {
    struct
    {
        // status ("RESP0")
        byte STCINT : 1;
        byte DUMMY1 : 1;
        byte RDSINT : 1;
        byte RSQINT : 1;
        byte DUMMY2 : 2;
        byte ERR : 1;
        byte CTS : 1;
        // RESP1
        byte RSSIILINT : 1; // RSSI Detect Low.
        byte RSSIHINT : 1;  // RSSI Detect High.
        byte SNRLINT : 1;   // SNR Detect Low.
        byte SNRHINT : 1;   // SNR Detect High.
        byte MULTLINT : 1;  // Multipath Detect Low
        byte MULTHINT : 1;  // Multipath Detect High
        byte DUMMY3 : 1;
        byte BLENDINT : 1; // Blend Detect Interrupt.
        // RESP2
        byte VALID : 1; // Valid Channel.
        byte AFCRL : 1; // AFC Rail Indicator.
        byte DUMMY4 : 1;
        byte SMUTE : 1; // Soft Mute Indicator. Indicates soft mute is engaged.
        byte DUMMY5 : 4;
        // RESP3
        byte STBLEND : 7; // Indicates amount of stereo blend in% (100 = full stereo, 0 = full mono).
        byte PILOT : 1;   // Indicates stereo pilot presence.
        // RESP4 to RESP7
        byte RSSI;    // RESP4 - Contains the current receive signal strength (0–127 dBμV).
        byte SNR;     // RESP5 - Contains the current SNR metric (0–127 dB).
        byte MULT;    // RESP6 - Contains the current multipath metric. (0 = no multipath; 100 = full multipath)
        byte FREQOFF; // RESP7 - Signed frequency offset (kHz).
    } resp;
    byte raw[8];
} si47x_rqs_status;

/*
 * FM_RDS_STATUS (0x24) command
 * Data type for command and response information 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 77 and 78
 */

// Command data type
typedef union {
    struct
    {
        byte INTACK : 1;     // Interrupt Acknowledge; 0 = RDSINT status preserved; 1 = Clears RDSINT.
        byte MTFIFO : 1;     // Empty FIFO; 0 = If FIFO not empty; 1 = Clear RDS Receive FIFO.
        byte STATUSONLY : 1; // Determines if data should be removed from the RDS FIFO.
        byte dummy : 5;
    } arg;
    byte raw;
} si47x_rds_command;

```cpp
// Response data type for current channel and reads an entry from the RDS FIFO.
typedef union {
    struct
    {
        // status ("RESP0")
        byte STCINT : 1;
        byte DUMMY1 : 1;
        byte RDSINT : 1;
        byte RSQINT : 1;
        byte DUMMY2 : 2;
        byte ERR : 1;
        byte CTS : 1;
        // RESP1
        byte RDSRECV : 1;      // RDS Received; 1 = FIFO filled to minimum number of groups set by RDSFIFOCNT.
        byte RDSSYNCLOST : 1;  // RDS Sync Lost; 1 = Lost RDS synchronization.
        byte RDSSYNCFOUND : 1; // RDS Sync Found; 1 = Found RDS synchronization.
        byte DUMMY3 : 1;
        byte RDSNEWBLOCKA : 1; // RDS New Block A; 1 = Valid Block A data has been received.
        byte RDSNEWBLOCKB : 1; // RDS New Block B; 1 = Valid Block B data has been received.
        byte DUMMY4 : 2;
        // RESP2
        byte RDSSYNC : 1; // RDS Sync; 1 = RDS currently synchronized.
        byte DUMMY5 : 1;
        byte GRPLOST : 1; // Group Lost; 1 = One or more RDS groups discarded due to FIFO overrun.
        byte DUMMY6 : 5;
        // RESP3 to RESP11
        byte RDSFIFOUSED; // RESP3 - RDS FIFO Used; Number of groups remaining in the RDS FIFO (0 if empty).
        byte BLOCKAH;     // RESP4 - RDS Block A; HIGH byte
        byte BLOCKAL;     // RESP5 - RDS Block A; LOW byte
        byte BLOCKBH;     // RESP6 - RDS Block B; HIGH byte
        byte BLOCKBL;     // RESP7 - RDS Block B; LOW byte
        byte BLOCKCH;     // RESP8 - RDS Block C; HIGH byte
        byte BLOCKCL;     // RESP9 - RDS Block C; LOW byte
        byte BLOCKDH;     // RESP10 - RDS Block D; HIGH byte
        byte BLOCKDL;     // RESP11 - RDS Block D; LOW byte
        // RESP12 - Blocks A to D Corrected Errors.
        // 0 = No errors;
        // 1 = 1–2 bit errors detected and corrected;
        // 2 = 3–5 bit errors detected and corrected.
        // 3 = Uncorrectable.
        byte BLED : 2;
        byte BLEC : 2;
        byte BLEB : 2;
        byte BLEA : 2;
    } resp;
    byte raw[13];
} si47x_rds_status;

/*
 * FM_RDS_INT_SOURCE property data type
 * See Si47XX PROGRAMMING GUIDE; AN332; page 103
 */
typedef union {
    struct
    {
        byte RDSRECV : 1;      // If set, generate RDSINT when RDS FIFO has at least FM_RDS_INT_FIFO_COUNT entries.
        byte RDSSYNCLOST : 1;  // If set, generate RDSINT when RDS loses synchronization.
        byte RDSSYNCFOUND : 1; // f set, generate RDSINT when RDS gains synchronization.
        byte DUMMY1 : 1;       // Always write to 0.
        byte RDSNEWBLOCKA : 1; // If set, generate an interrupt when Block A data is found or subsequently changed
        byte RDSNEWBLOCKB : 1; // If set, generate an interrupt when Block B data is found or subsequently changed
        byte DUMMY2 : 10;      // Reserved - Always write to 0.
    } refined;
    byte raw[2];
} si47x_rds_int_source;

/*
 * Data type for FM_RDS_CONFIG Property
 * 
 * IMPORTANT: all block errors must be less than or equal the associated block error threshold for the group 
 * to be stored in the RDS FIFO. 
 * 0 = No errors; 1 = 1–2 bit errors detected and corrected; 2 = 3–5 bit errors detected and corrected; 3 = Uncorrectable.
 * Recommended Block Error Threshold options:
 *  2,2,2,2 = No group stored if any errors are uncorrected.
 *  3,3,3,3 = Group stored regardless of errors.
 *  0,0,0,0 = No group stored containing corrected or uncorrected errors.
 *  3,2,3,3 = Group stored with corrected errors on B, regardless of errors on A, C, or D.
 *  
 */
typedef union {
    struct
    {
        byte RDSEN : 1; // 1 = RDS Processing Enable.
        byte DUMMY1 : 7;
        byte BLETHD : 2; // Block Error Threshold BLOCKD
        byte BLETHC : 2; // Block Error Threshold BLOCKC.
        byte BLETHB : 2; // Block Error Threshold BLOCKB.
        byte BLETHA : 2; // Block Error Threshold BLOCKA.
    } arg;
    byte raw[2];
} si47x_rds_config;

/*
 * Block A data type
 */
typedef union {
    struct
    {
        unsigned pi;
    } refined;
    struct
    {
        byte lowValue;
        byte highValue; // Most Significant byte first
    } raw;
} si47x_rds_blocka;

/*
 * Block B data type
 * More about Group Type Contents see: https://github.com/pu2clr/SI4735/tree/master/examples/SI4735_RDS
 * See also Si47XX PROGRAMMING GUIDE; AN332; pages 78 and 79
 */
typedef union {
    struct
    {
        byte content : 5;            // Depends on Group Type and Version codes.
        byte programType : 5;        // PTY (Program Type) code
        byte trafficProgramCode : 1; // 0 = No Traffic Alerts; 1 = Station gives Traffic Alerts
        byte versionCode : 1;        // 0=A; 1=B
        byte groupType : 4;          // Group Type code.

    } refined;
    struct
    {
        byte lowValue;
        byte highValue; // Most Significant Byte first
    } raw;
} si47x_rds_blockb;

typedef union {
    struct
    {
        byte offset : 5;
        byte offset_sense : 1; //
        byte minute : 6;       //
        byte hour : 4;         //
        unsigned mjd;
    } refined;
    byte raw[4];
} si47x_rds_date_time;

/* AGC data types
 * FM / AM and SSB structure to AGC
 * See Si47XX PROGRAMMING GUIDE; AN332; For FM page 80; for AM page 142
 * See AN332 REV 0.8 Universal Programming Guide Amendment for SI4735-D60 SSB and NBFM patches; page 18. 
 */
typedef union {
    struct {
        // status ("RESP0")
        byte STCINT : 1;
        byte DUMMY1 : 1;
        byte RDSINT : 1;   // Not used for AM/SSB
        byte RSQINT : 1;
        byte DUMMY2 : 2;
        byte ERR : 1;
        byte CTS : 1;
        // RESP1
        byte AGCDIS : 1; // This bit indicates if the AGC is enabled or disabled. 0 = AGC enabled; 1 = AGC disabled.
        byte DUMMY:7;
        // RESP2
        byte AGCIDX; // For FM (5 bits - READ_LNA_GAIN_INDEX - 0 = Minimum attenuation (max gain)). For AM (8 bits). This byte reports the current AGC gain index.
    } refined;
    byte raw[3];
} si47x_agc_status;

/* 
 * If FM, Overrides AGC setting by disabling the AGC and forcing the LNA to have a certain gain that ranges between 0 
 * (minimum attenuation) and 26 (maximum attenuation).
 * If AM, overrides the AGC setting by disabling the AGC and forcing the gain index that ranges between 0
 * See Si47XX PROGRAMMING GUIDE; AN332; For FM page 81; for AM page 143
 */
typedef union {
    struct {
        // ARG1
        byte AGCDIS : 1; // if set to 1 indicates if the AGC is disabled. 0 = AGC enabled; 1 = AGC disabled.
        byte DUMMY : 7;
        // ARG2
        byte AGCIDX; // AGC Index; If AMAGCDIS = 1, this byte forces the AGC gain index; 0 = Minimum attenuation (max gain)
    } arg;
    byte raw[2];
} si47x_agc_overrride;

/* 
 * Sets the I2C Bus Address
 * @param senPin 0 -  when the pin SEN (16 on SSOP version or pin 6 on QFN version) is set to low (GND - 0V)
 *               1 -  when the pin SEN (16 on SSOP version or pin 6 on QFN version) is set to high (+3.3V)
 *
 * The default value is 0x11 (senPin = 0). In this case you have to ground the pin SEN of the SI473X. 
 * If you want to change this address, call this function with senPin = 1
 * ATTENTION: 
 * The parameter senPin is not the I2C bus address. It is the SEN pin setup of the schematic (eletronic circuit).
 * If it is connected to the ground, call this function with senPin = 0; else senPin = 1.
 * Acctually you do not need to use this function if the SEN PIN is configured to ground (GND).
 */
inline void setDeviceI2CAddress(uint16_t senPin)

/* 
 * Scans for two possible addresses for the Si37XX (0x11 or 0x63 )
 * This function also sets the system to the found I2C bus address of Si47XX.
 * 
 * @param uint8_t resetPin MCU Mater (Arduino) reset pin
 * @return 0x11   if the SEN pin of the Si47XX is low or 0x63 if the SEN pin of
 *                the Si47XX is HIGH or 0x0 if error. 
 *                
 * You do not need to use this function if the SEN PIN is configured to ground (GND). The default I2C address is 0x11.
 * Use this function if you do not know how the SEN pin is configured.
 */
int16_t SI4735::getDeviceI2CAddress(uint8_t resetPin)

/* 
 * Starts the Si473X device. 
 * 
 * @param byte resetPin Digital Arduino Pin used to RESET command 
 * @param byte interruptPin interrupt Arduino Pin (see your Arduino pinout). If less than 0, iterrupt disabled
 * @param byte defaultFunction
 */
void SI4735::setup(byte resetPin, byte interruptPin, byte defaultFunction)

/* 
 * Starts the Si473X device.  
 * Use this setup if you are not using interrupt resource
 * 
 * @param byte resetPin Digital Arduino Pin used to RESET command 
 * @param byte defaultFunction
 */
void SI4735::setup(byte resetPin, byte defaultFunction)

#include <SI4735.h>

#define INTERRUPT_PIN 2
#define RESET_PIN 12

SI4735 si4735;

void setup()
{
    si4735.setup(RESET_PIN, INTERRUPT_PIN, FM_FUNCTION);
}

/*
 * Set the Power Up parameters for si473X. 
 * Use this method to chenge the defaul behavior of the Si473X. Use it before PowerUp()
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 65 and 129
 * @param byte CTSIEN sets Interrupt anabled or disabled (1 = anabled and 0 = disabled )
 * @param byte GPO2OEN sets GP02 Si473X pin enabled (1 = anabled and 0 = disabled )
 * @param byte PATCH  Used for firmware patch updates. Use it always 0 here. 
 * @param byte XOSCEN byte XOSCEN set external Crystal enabled or disabled 
 * @param byte FUNC sets the receiver function have to be used [0 = FM Receive; 1 = AM (LW/MW/SW) and SSB (if SSB patch apllied)]
 * @param byte OPMODE set the kind of audio mode you want to use.
 */
void SI4735::setPowerUp(byte CTSIEN, byte GPO2OEN, byte PATCH, byte XOSCEN, byte FUNC, byte OPMODE)

/*
 * Powerup in Analog Mode
 * You have to call setPowerUp before call analogPowerUp. 
 * Use setPowerUp to select FM, AM or SSB (if SSB patch apllied) mode.
 */
void SI4735::analogPowerUp(void) 

    // Set the initial SI473X behavior
    // CTSIEN   1 -> Interrupt anabled;
    // GPO2OEN  1 -> GPO2 Output Enable;
    // PATCH    0 -> Boot normally;
    // XOSCEN   1 -> Use external crystal oscillator;
    // FUNC     defaultFunction = 0 = FM Receive; 1 = AM (LW/MW/SW) Receiver.
    // OPMODE   SI473X_ANALOG_AUDIO = 00000101 = Analog audio outputs (LOUT/ROUT).

    setPowerUp(1, 1, 0, 1, defaultFunction, SI473X_ANALOG_AUDIO);
    analogPowerUp();

/* 
 * Moves the device from powerup to powerdown mode.
 * After Power Down command, only the Power Up command is accepted.
 */
void SI4735::powerDown(void)

/*
 * Set the frequency to the corrent function of the Si4735 (AM or FM)
 * You have to call setup or setPowerUp before call setFrequency.
 * 
 * @param unsigned freq Is the frequency to change. For example, FM => 10390 = 103.9 MHz; AM => 810 = 810 KHz. 
 */
void SI4735::setFrequency(unsigned freq) 

    si4735.setFM(); 
    si4735.setFrequency(fm_freq); 
    showStatus(fm_freq,"MHz");

/*
 *  Increments the current frequency on current band/function by using the current step.
 *  See setFrequencyStep
 */ 
void SI4735::frequencyUp()

/*
 *  Decrements the current frequency on current band/function by using the current step.
 *  See setFrequencyStep
 */ 
void SI4735::frequencyDown()

/*
 * Selects the tuning capacitor value.
 * For FM, Antenna Tuning Capacitor is valid only when using TXO/LPI pin as the antenna input.
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 71 and 136
 * 
 * @param capacitor If zero, the tuning capacitor value is selected automatically. 
 *                  If the value is set to anything other than 0:
 *                  AM - the tuning capacitance is manually set as 95 fF x ANTCAP + 7 pF. ANTCAP manual range is 
 *                       1 to 6143;
 *                  FM - the valid range is 0 to 191.    
 *                  According to Silicon Labs, automatic capacitor tuning is recommended (value 0). 
 */
void SI4735::setTuneFrequencyAntennaCapacitor(unsigned capacitor)

/*
 * If set, executes fast and invalidated tune. The tune status will not be accurate
 * @param FAST if 1 executes fast and invalidated tune. Defult value is 0.
 */
inline void SI4735::setTuneFrequencyFast(byte FAST) 

/*
 * Freeze Metrics During Alternate Frequency Jump. Only used on FM. 
 */ 
inline void SI4735::setTuneFrequencyFreeze(byte FREEZE) 

/*
 * Look for a station 
 * See Si47XX PROGRAMMING GUIDE; AN332; page 72
 * 
 * @param SEEKUP Seek Up/Down. Determines the direction of the search, either UP = 1, or DOWN = 0. 
 * @param Wrap/Halt. Determines whether the seek should Wrap = 1, or Halt = 0 when it hits the band limit.
 */
void SI4735::seekStation(byte SEEKUP, byte WRAP)

    si4735.seekStation(1,1);

/*
 * Search for the next station 
 */
void SI4735::seekStationUp() 

/*
 * Search the previous station
 */
void SI4735::seekStationDown()

/*
 * Sets the bottom and top frequency of the AM band for seek. Default is 520 to 1710.
 * @param uint16_t bottom - the bottom of the AM band for seek
 * @param uint16_t    top - the top of the AM band for seek
 */
void SI4735::setSeekAmLimits(uint16_t bottom, uint16_t top)

/*
 * Selects frequency spacingfor AM seek. Default is 10 kHz spacing.
 * @param uint16_t spacing - step in KHz
 */
void SI4735::setSeekAmSpacing(uint16_t spacing)

/*
 * Sets the SNR threshold for a valid AM Seek/Tune. 
 * If the value is zero then SNR threshold is not considered when doing a seek. Default value is 5 dB.
 */
void SI4735::setSeekSrnThreshold(uint16_t value)

/*
 * Sets the RSSI threshold for a valid AM Seek/Tune. 
 * If the value is zero then RSSI threshold is not considered when doing a seek. Default value is 25 dBμV.
 */
void SI4735::setSeekRssiThreshold(uint16_t value)

/*
 * Set the radio to AM function. It means: LW, MW and SW.
 */ 
void SI4735::setAM()

/*
 * Set the radio to AM (LW/MW/SW) function. 
 * 
 * @param fromFreq minimum frequency for the band
 * @param toFreq maximum frequency for the band
 * @param initialFreq initial frequency 
 * @param step step used to go to the next channel   
 */
void SI4735::setAM(unsigned fromFreq, unsigned toFreq, unsigned initialFreq, byte step)

/*
 * Set the radio to FM function
 */
void SI4735::setFM()

/*
 * Set the radio to FM function. 
 * 
 * @param fromFreq minimum frequency for the band
 * @param toFreq maximum frequency for the band
 * @param initialFreq initial frequency (default frequency)
 * @param step step used to go to the next channel   
 */
void SI4735::setFM(unsigned fromFreq, unsigned toFreq, unsigned initialFreq, byte step)

    switch (key)
    {
    case 'A':
      si4735.setAM();
      si4735.setFrequency(am_freq);
      break;
    case 'F':
      si4735.setFM();
      si4735.setFrequency(fm_freq);
      break;
      .
      .
      .

/*
 * Returns true if the radio is running FM (FM_TUNE_FREQ).
 */ 
bool SI4735::isCurrentTuneFM()

/* 
 * Set the volume level
 * @param byte volume (domain: 0 - 63) 
 */
void SI4735::setVolume(byte volume)

  si4735.setVolume(45);

/*
 * Gets the current volume level.
 */
byte SI4735::getVolume()

/*
 *  Set sound volume level Up   
 */
void SI4735::volumeUp()

/*
 *  Set sound volume level Down   
 */
void SI4735::volumeDown()

    switch (key)
    {
    case '+':
        si4735.volumeUp();
        break;
    case '-': 
        si4735.volumeDown();
        break;
    .
    .
    .    

/*
 * Sets the audio on or off
 * @param value if true, mute the audio; if false unmute the audio.
 */ 
void setAudioMute( bool value)

/*
 * Returns the current volume level
 */ 
inline byte SI4735::getCurrentVolume() 

/*
 * Sets RSSI threshold for stereo blend (Full stereo above threshold, blend below threshold). 
 * To force stereo, set this to 0. To force mono, set this to 127.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 90. 
 */
void SI4735::setFmBlendStereoThreshold(uint8_t parameter)

/*
 * Sets RSSI threshold for mono blend (Full mono below threshold, blend above threshold). 
 * To force stereo set this to 0. To force mono set this to 127. Default value is 30 dBμV.
 *  See Si47XX PROGRAMMING GUIDE; AN332; page 56.
 */
void SI4735::setFmBlendMonoThreshold(uint8_t parameter)

/* 
 * Sets RSSI threshold for stereo blend. (Full stereo above threshold, blend below threshold.) 
 * To force stereo, set this to 0. To force mono, set this to 127. Default value is 49 dBμV.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 59. 
 */
void SI4735::setFmBlendRssiStereoThreshold(uint8_t parameter)

/*
 * Sets RSSI threshold for mono blend (Full mono below threshold, blend above threshold). 
 * To force stereo, set this to 0. To force mono, set this to 127. Default value is 30 dBμV.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 59.  
 */
void SI4735::setFmBLendRssiMonoThreshold(uint8_t parameter)

/*
 * Sets SNR threshold for stereo blend (Full stereo above threshold, blend below threshold). 
 * To force stereo, set this to 0. To force mono, set this to 127. Default value is 27 dB.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 59.  
 */
void SI4735::setFmBlendSnrStereoThreshold(uint8_t parameter)

/*
 * Sets SNR threshold for mono blend (Full mono below threshold, blend above threshold). 
 * To force stereo, set this to 0. To force mono, set this to 127. Default value is 14 dB.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 59. 
 */
void SI4735::setFmBLendSnrMonoThreshold(uint8_t parameter)

/* 
 * Sets multipath threshold for stereo blend (Full stereo below threshold, blend above threshold). 
 * To force stereo, set this to 100. To force mono, set this to 0. Default value is 20.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 60.
 */
void SI4735::setFmBlendMultiPathStereoThreshold(uint8_t parameter)

/*
 * Sets Multipath threshold for mono blend (Full mono above threshold, blend below threshold). 
 * To force stereo, set to 100. To force mono, set to 0. The default is 60.
 * See Si47XX PROGRAMMING GUIDE; AN332; page 60.
 */
void SI4735::setFmBlendMultiPathMonoThreshold(uint8_t parameter)

/*
 * Gets the current frequency of the Si4735 (AM/SSB or FM)
 * The method status do it an more. See getStatus below. 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 73 (FM) and 139 (AM)
 */
unsigned SI4735::getFrequency()

/*
 * Gets the current frequency saved in memory. 
 * Unlike getFrequency, this method gets the current frequency recorded after the last setFrequency command. 
 * This method avoids bus traffic and CI processing.
 * However, you can not get others status information like RSSI.
 */
unsigned SI4735::getCurrentFrequency() 

/*
 * Gets the current status  of the Si4735 (AM or FM)
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 73 (FM) and 139 (AM)
 *
 */
void SI4735::getStatus()


/*
 * Gets the current status  of the Si4735 (AM or FM)
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 73 (FM) and 139 (AM)
 * 
 * @param byte INTACK Seek/Tune Interrupt Clear. If set, clears the seek/tune complete interrupt status indicator;
 * @param byte CANCEL Cancel seek. If set, aborts a seek currently in progress;
 * 
 */
void SI4735::getStatus(byte INTACK, byte CANCEL) {

/*
 * Tune complete has been triggered (STCINT)
 */
inline bool SI4735::getTuneCompleteTriggered()

/* 
 * Gets Received Signal Quality Interrupt(RSQINT)
 * 
 */
inline bool SI4735::getSignalQualityInterrup()

/* 
 * Gets Radio Data System (RDS) Interrupt
 */
inline bool getRadioDataSystemInterrupt()

/*
 * Return the Error flag (true or false) of status of the least Tune or Seek 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 63
 * @return true or false
 */
inline bool SI4735::getStatusError()

/*
 * Gets the Error flag of status response 
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 63
 */
inline bool SI4735::getStatusCTS()

/* 
 * Returns true if the AFC rails (AFC Rail Indicator). 
 */
inline bool SI4735::getACFIndicator()

/* 
 * Returns true if a seek hit the band limit (WRAP = 0 in FM_START_SEEK) or 
 * wrapped to the original frequency (WRAP = 1).
 */
inline bool SI4735::getBandLimit()

/*
 * Received Signal Strength Indicator.
 * This byte contains the receive signal strength when tune is complete (dBμV).
 */
inline byte SI4735::getReceivedSignalStrengthIndicator()

/*
 * SNR.
 * This byte contains the SNR metric when tune is complete (dB).
 */
inline byte SI4735::getStatusSNR()

/* 
 * Multipath.
 * This byte contains the multipath metric when tune is complete. 
 * Multipath indi- cator is available only for Si474x, Si4706-C30 and later and 
 * Si4704/05/30/31/34/35/84/85-D50 and later.
 */
inline byte SI4735::getStatusMULT()

/* 
 * Read Antenna Tuning Capacitor (Si4704/05/06/2x only). 
 * Returns a byte that contains the current antenna tuning capacitor value.
 */
inline byte SI4735::getAntennaTuningCapacitor()

/*
 * Returns true if the channel is currently valid as determined by the seek/tune properties (0x1403, 0x1404, 0x1108) 
 * and would have been found during a Seek.
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 63
 */
inline bool SI4735::getStatusValid()

/*  
 * Queries the status of the Received Signal Quality (RSQ) of the current channel. The methods getCurrentRSSI(), * * getCurrentSNR() etc,
 * Call this method first and then you can call getCurrentRSSI(), getCurrentSNR() etc. 
 * 
 * @param INTACK Interrupt Acknowledge; 0 = Interrupt status preserved; 1 = Clears RSQINT, SNRHINT, SNRLINT, RSSIHINT, RSSILINT
 */
void getCurrentReceivedSignalQuality(byte INTACK)

/* 
 * Gets current receive signal strength (0–127 dBμV).
 * AM and FM
 */
inline byte SI4735::getCurrentRSSI() 

/*
 * Gets current SNR metric (0–127 dB).
 * AM and FM
 */
inline byte SI4735::getCurrentSNR() 

/* 
 * Returns true if RSSI Detect Low.
 * AM and FM
 */ 
inline bool SI4735::getCurrentRssiDetectLow() 

/* 
 * Return true if RSSI Detect High
 * AM and FM
 */ 
inline bool SI4735::getCurrentRssiDetectHigh() 

/* 
 * Returns true if SNR Detect Low.
 */ 
inline bool SI4735::getCurrentSnrDetectLow() 

/* 
 * Returns true if SNR Detect High
 */ 
inline bool SI4735::getCurrentSnrDetectHigh() 

/*
 *  Returns true if Valid Channel.
 */ 
inline bool SI4735::getCurrentValidChannel() 

/*
 *  Returns true AFC (Automatic Frequency Control) Rail Indicator.
 */ 
inline bool SI4735::getCurrentAfcRailIndicator() 

/*
 * Returns true if soft mute is engaged.
 */
inline bool SI4735::getCurrentSoftMuteIndicator() 

/* 
 *  Returns the amount of stereo blend in% (100 = full stereo, 0 = full mono).
 */ 
inline byte SI4735::getCurrentStereoBlend()

/*
 * Returns true if stereo pilot presence.
 */ 
inline bool SI4735::getCurrentPilot() 

/* 
 * Returns the current multipath metric. (0 = no multipath; 100 = full multipath)
 */ 
inline byte SI4735::getCurrentMultipath() 

/* 
 * Returns Signed frequency offset (kHz).
 */ 
inline byte SI4735::getCurrentSignedFrequencyOffset() 

/* 
 * Returns true if Multipath Detect Low.
 */ 
inline bool SI4735::getCurrentMultipathDetectLow()  

/*
 * Returns true if Multipath Detect High
 */ 
inline bool SI4735::getCurrentMultipathDetectHigh()   

/*
 * Returns true if Blend Detect Interrupt
 */ 
inline bool SI4735::getCurrentBlendDetectInterrupt()  

/*
 * Queries AGC STATUS
 * See Si47XX PROGRAMMING GUIDE; AN332; For FM page 80; for AM page 142.
 * See AN332 REV 0.8 Universal Programming Guide Amendment for SI4735-D60 SSB and NBFM patches; page 18. 
 * After call this method, you can call isAgcEnabled to know the AGC status and getAgcGainIndex to know the gain index value.
 */
void SI4735::getAutomaticGainControl()

/* 
 *  Returns true if the AGC is enabled
 */ 
inline bool isAgcEnabled()

/* 
 *  Returns the current AGC gain index.
 */ 
inline byte getAgcGainIndex() 

/* 
 * If FM, overrides AGC setting by disabling the AGC and forcing the LNA to have a certain gain that ranges between 0 
 * (minimum attenuation) and 26 (maximum attenuation);
 * If AM/SSB, Overrides the AM AGC setting by disabling the AGC and forcing the gain index that ranges between 0 
 * (minimum attenuation) and 37+ATTN_BACKUP (maximum attenuation);
 * 
 * @param byte AGCDIS This param selects whether the AGC is enabled or disabled (0 = AGC enabled; 1 = AGC disabled);
 * @param byte AGCIDX AGC Index (0 = Minimum attenuation (max gain); 1 – 36 = Intermediate attenuation); 
 *             > 37 - Maximum attenuation (min gain) ).
 * 
 * See Si47XX PROGRAMMING GUIDE; AN332; For FM page 81; for AM page 143 
 */
void SI4735::setAutomaticGainControl(byte AGCDIS, byte AGCIDX)

/*
 * Sets the maximum gain for automatic volume control.
 * If no parameter is sent, it will be consider 48dB.
 *
 * @param uint8_t gain  Select a value between 12 and 192.  Defaul value 48dB.
 * 
 */
void SI4735::setAvcAmMaxGain( uint8_t gain)

    si4735.setAvcAmMaxGain(); // For 48dB gain
    .
    .
    si4735.setAvcAmMaxGain(16); // For 16dB gain
    .
    .
    si4735.setAvcAmMaxGain(x);  // For xdB gain if x is a value between 12 ans 192.

/*
 * Gets the current Automatic Volume Control Maximum gain in dB
 */
inline uint8_t getCurrentAvcAmMaxGain() 

/*
 * sets soft mute max attenuation for AM 
 * @patam uint8_t smattn if 0 disable.  Default attenuation is 8dB  
 */
inline void setAmSoftMuteMaxAttenuation( uint8_t smattn) 

/*
 * sets soft mute max attenuation for AM to 0
 */
inline void setAmSoftMuteMaxAttenuation() 

/*
 * Selects the bandwidth of the channel filter for AM reception. The choices are 6, 4, 3, 2, 2.5, 1.8, or 1 (kHz). 
 * The default bandwidth is 2 kHz.
 * Works only in AM / SSB (LW/MW/SW) 
 * @param AMCHFLT the choices are:   0 = 6 kHz Bandwidth;                    
 *                                   1 = 4 kHz Bandwidth;
 *                                   2 = 3 kHz Bandwidth;
 *                                   3 = 2 kHz Bandwidth;
 *                                   4 = 1 kHz Bandwidth;
 *                                   5 = 1.8 kHz Bandwidth;
 *                                   6 = 2.5 kHz Bandwidth. 
 * @param AMPLFLT Enables the AM Power Line Noise Rejection Filter.
 */
void setBandwidth(byte AMCHFLT, byte AMPLFLT)

/*
 * Returns the final 2 digits of Part Number (HEX)
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwarePN()

/*
 * Returns the Firmware Major Revision (ASCII).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwareFWMAJOR()

/*
 * Returns the Firmware Minor Revision (ASCII).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwareFWMINOR()

/*
 * Returns the Patch ID High Byte (HEX).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwarePATCHH()

/*
 * Returns the Patch ID Low Byte (HEX).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwarePATCHL()

/*
 * Returns the Component Major Revision (ASCII).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwareCMPMAJOR()

/*
 * Returns the Component Minor Revision (ASCII).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66.
 */
inline byte SI4735::getFirmwareCMPMINOR()

/*
 * Returns the Chip Revision (ASCII).
 * See Si47XX PROGRAMMING GUIDE; AN332; page 66
 */
inline byte SI4735::getFirmwareCHIPREV()

/* 
 * Starts the control variables for RDS.
 */  
void SI4735::RdsInit()

/* 
 * Configures interrupt related to RDS
 * Use this method if want to use interrupt
 * See Si47XX PROGRAMMING GUIDE; AN332; page 103
 * 
 * @param RDSRECV If set, generate RDSINT when RDS FIFO has at least FM_RDS_INT_FIFO_COUNT entries.
 * @param RDSSYNCLOST If set, generate RDSINT when RDS loses synchronization.
 * @param RDSSYNCFOUND set, generate RDSINT when RDS gains synchronization.
 * @param RDSNEWBLOCKA If set, generate an interrupt when Block A data is found or subsequently changed
 * @param RDSNEWBLOCKB If set, generate an interrupt when Block B data is found or subsequently changed
 */
void SI4735::setRdsIntSource(byte RDSNEWBLOCKB, byte RDSNEWBLOCKA, byte RDSSYNCFOUND, byte RDSSYNCLOST, byte RDSRECV)

/*
 * Set RDS property 
 * 
 * @param byte RDSEN RDS Processing Enable; 1 = RDS processing enabled.
 * @param byte BLETHA Block Error Threshold BLOCKA.   
 * @param byte BLETHB Block Error Threshold BLOCKB.  
 * @param byte BLETHC Block Error Threshold BLOCKC.  
 * @param byte BLETHD Block Error Threshold BLOCKD. 
 *  
 * IMPORTANT: 
 * All block errors must be less than or equal the associated block error threshold 
 * for the group to be stored in the RDS FIFO. 
 * 0 = No errors.
 * 1 = 1–2 bit errors detected and corrected. 
 * 2 = 3–5 bit errors detected and corrected. 
 * 3 = Uncorrectable.
 * Recommended Block Error Threshold options:
 *  2,2,2,2 = No group stored if any errors are uncorrected.
 *  3,3,3,3 = Group stored regardless of errors.
 *  0,0,0,0 = No group stored containing corrected or uncorrected errors.
 *  3,2,3,3 = Group stored with corrected errors on B, regardless of errors on A, C, or D.
 */
void SI4735::setRdsConfig(byte RDSEN, byte BLETHA, byte BLETHB, byte BLETHC, byte BLETHD)

/*
 * RDS COMMAND FM_RDS_STATUS
 * See Si47XX PROGRAMMING GUIDE; AN332; pages 77 and 78
 * @param INTACK Interrupt Acknowledge; 0 = RDSINT status preserved. 1 = Clears RDSINT.
 * @param MTFIFO 0 = If FIFO not empty, read and remove oldest FIFO entry; 1 = Clear RDS Receive FIFO.
 * @param STATUSONLY Determines if data should be removed from the RDS FIFO.
 */
void SI4735::getRdsStatus(byte INTACK, byte MTFIFO, byte STATUSONLY)

/*
 * Gets RDS Status.
 * Call getRdsStatus(byte INTACK, byte MTFIFO, byte STATUSONLY) if you want other behaviour
 * same getRdsStatus(0,0,0)
 */
void SI4735::getRdsStatus() 

/*
 * Returns true if the number of the groups is filled.
 * (1 = FIFO filled to minimum number of groups)
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsReceived()       

/* 
 * Returns true if when the RDS synchronization status is lost (1 = Lost RDS synchronization)
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsSyncLost()  

/* 
 * Returns true when RDS synchronization status is found (Found RDS synchronization)
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsSyncFound() 

/* 
 * Returns true when a valid Block A data has been received.
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsNewBlockA() 

/* 
 * Returns true when a valid Block B data has been received.
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsNewBlockB() 

/* 
 * Returns true when RDS currently synchronized.
 * You have to call getRdsStatus before. 
 */ 
inline bool getRdsSync() 

/*
 * Returns true when One or more RDS groups discarded due to FIFO overrun.
 * You have to call getRdsStatus before. 
 */ 
 inline bool getGroupLost()          

/*
 * Returns the number of groups remaining in the RDS FIFO (0 if empty).
 * You have to call getRdsStatus before.   
 */
inline byte getNumRdsFifoUsed() 

/* 
 * Returns the programa type. 
 * Read the Block A content
 */  
unsigned SI4735::getRdsPI(void) 

/*
 * Returns the Group Type (extracted from the Block B) 
 */ 
unsigned SI4735::getRdsGroupType(void)

/*
 * Gets the version code (extracted from the Block B)
 * Returns  0=A or 1=B
 */
unsigned SI4735::getRdsVersionCode(void)

/* 
 * Returns the Program Type (extracted from the Block B)
 */ 
unsigned SI4735::getRdsProgramType(void)

/*
 * Gets the RDS Text when the message is of the Group Type 2 version A
 */  
String SI4735::getRdsText(void)

/* 
 * Gets the RDS time and date when the Group type is 4 
 */  
String SI4735::getRdsTime()

/*
   Call it first if you are applying a patch on SI4735. 
   Used to confirm if the patch is compatible with the internal device library revision.
   See Si47XX PROGRAMMING GUIDE; AN332; pages 64 and 215-220.
*/
si47x_firmware_query_library SI4735::queryLibraryId()

/*
 *  This method can be used to prepare the device to apply SSBRX patch
 *  Call queryLibraryId before call this method. 
 *  Powerup the device by issuing the POWER_UP command with FUNC = 1 (AM/SW/LW Receive) 
 *  See Si47XX PROGRAMMING GUIDE; AN332; pages 64 and 215-220 and
 *  AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE AMENDMENT FOR SI4735-D60 SSB AND NBFM PATCHES; page 7.
 * 
 *  @return a struct si47x_firmware_query_library (see it in SI4735.h)
 */
void SI4735::patchPowerUp()

/*
 *  Transfers the content of a patch stored in a array of bytes to the SI4735 device. 
 *  You must mount an array as shown below and know the size of that array as well.
 *  
 *  See Si47XX PROGRAMMING GUIDE; AN332; pages 64 and 215-220.  
 * 
 *  It is importante to say  that patches to the SI4735 are distributed in binary form and 
 *  have to be transferred to the internal RAM of the device by the host MCU (in this case Arduino).
 *  Since the RAM is volatile memory, the patch stored into the device gets lost when you turn off 
 *  the system. Consequently, the content of the patch has to be transferred again to the device 
 *  each time after turn on the system or reset the device.
 * 
 *  The disadvantage of this approach is the amount of memory used by the patch content. 
 *  This may limit the use of other radio functions you want implemented in Arduino.
 * 
 *  Example of content:
 *  const PROGMEM byte ssb_patch_content_full[] =
 *   { // SSB patch for whole SSBRX full download
 *       0x15, 0x00, 0x0F, 0xE0, 0xF2, 0x73, 0x76, 0x2F,
 *       0x16, 0x6F, 0x26, 0x1E, 0x00, 0x4B, 0x2C, 0x58,
 *       0x16, 0xA3, 0x74, 0x0F, 0xE0, 0x4C, 0x36, 0xE4,
 *          .
 *          .
 *          .
 *       0x16, 0x3B, 0x1D, 0x4A, 0xEC, 0x36, 0x28, 0xB7,
 *       0x16, 0x00, 0x3A, 0x47, 0x37, 0x00, 0x00, 0x00,
 *       0x15, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9D, 0x29};   
 * 
 *  const int size_content_full = sizeof ssb_patch_content_full;
 * 
 *  @param ssb_patch_content point to array of bytes content patch.
 *  @param ssb_patch_content_size array size (number of bytes). The maximum size allowed for a patch is 15856 bytes
 * 
 *  @return false if an error is found.
 */
bool SI4735::downloadPatch(byte *ssb_patch_content, unsigned ssb_patch_content_size)

/* 
 * Sets the SSB Beat Frequency Offset (BFO). 
 * @param offset 16-bit signed value (unit in Hz). The valid range is -16383 to +16383 Hz. 
 */ 
void SI4735::setSSBBfo(int offset)

/*
 * Set the SSB receiver mode details:
 * 1) Enable or disable AFC track to carrier function for receiving normal AM signals;
 * 2) Set the audio bandwidth;
 * 3) Set the side band cutoff filter;
 * 4) Set soft-mute based on RSSI or SNR;
 * 5) Enable or disbable automatic volume control (AVC) function. 
 * 
 * See AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE; page 24 
 * 
 * @param AUDIOBW SSB Audio bandwidth; 0 = 1.2KHz (default); 1=2.2KHz; 2=3KHz; 3=4KHz; 4=500Hz; 5=1KHz.
 * @param SBCUTFLT SSB side band cutoff filter for band passand low pass filter
 *                 if 0, the band pass filter to cutoff both the unwanted side band and high frequency 
 *                  component > 2KHz of the wanted side band (default).
 * @param AVC_DIVIDER set 0 for SSB mode; set 3 for SYNC mode.
 * @param AVCEN SSB Automatic Volume Control (AVC) enable; 0=disable; 1=enable (default).
 * @param SMUTESEL SSB Soft-mute Based on RSSI or SNR.
 * @param DSP_AFCDIS DSP AFC Disable or enable; 0=SYNC MODE, AFC enable; 1=SSB MODE, AFC disable. 
 */
void SI4735::setSSBConfig(byte AUDIOBW, byte SBCUTFLT, byte AVC_DIVIDER, byte AVCEN, byte SMUTESEL, byte DSP_AFCDIS)

/* 
 * Sets DSP AFC disable or enable
 * 0 = SYNC mode, AFC enable
 * 1 = SSB mode, AFC disable
 */
void SI4735::setSSBDspAfc(byte DSP_AFCDIS)

/* 
 * Sets SSB Soft-mute Based on RSSI or SNR Selection:
 * 0 = Soft-mute based on RSSI (default).
 * 1 = Soft-mute based on SNR.
 */
void SI4735::setSSBSoftMute(byte SMUTESEL)

/*
 * sets soft mute max attenuation for SSB
 * @patam uint8_t smattn if 0 disable.  Default attenuation is 8dB   
 */
inline void setSsbSoftMuteMaxAttenuation( uint8_t smattn) 

/*
 * sets soft mute max attenuation for SSB to 0
 */
inline void setSsbSoftMuteMaxAttenuation() 

/*
 * Sets SSB Automatic Volume Control (AVC) for SSB mode
 * 0 = Disable AVC.
 * 1 = Enable AVC (default).
 */
void SI4735::setSSBAutomaticVolumeControl(byte AVCEN)

/*
 * Sets AVC Divider
 * for SSB mode, set divider = 0
 * for SYNC mode, set divider = 3 Other values = not allowed.
 */
void SI4735::setSSBAvcDivider(byte AVC_DIVIDER)

/* 
 * Sets SBB Sideband Cutoff Filter for band pass and low pass filters:
 * 0 = Band pass filter to cutoff both the unwanted side band and high frequency components > 2.0 kHz of the wanted side band. (default)
 * 1 = Low pass filter to cutoff the unwanted side band. 
 * Other values = not allowed.
 */
void SI4735::setSBBSidebandCutoffFilter(byte SBCUTFLT)

/*
 * SSB Audio Bandwidth for SSB mode
 * 
 * 0 = 1.2 kHz low-pass filter (default)
 * 1 = 2.2 kHz low-pass filter .
 * 2 = 3.0 kHz low-pass filter.
 * 3 = 4.0 kHz low-pass filter.
 * 4 = 500 Hz band-pass filter for receiving CW signal, i.e. [250 Hz, 750 Hz]
 *     with center frequency at 500 Hz when USB is selected or [-250 Hz, -750 1Hz] with center 
 *     frequency at -500Hz when LSB is selected* .
 * 5 = 1 kHz band-pass filter for receiving CW signal, i.e. [500 Hz, 1500 Hz] with center 
 *     frequency at 1 kHz when USB is selected or [-500 Hz, -1500 1 Hz] with center frequency 
 *     at -1kHz when LSB is selected* .
 * Other values = reserved.
 * Note:
 *   If audio bandwidth selected is about 2 kHz or below, it is recommended to set SBCUTFLT[3:0] to 0 
 *   to enable the band pass filter for better high- cut performance on the wanted side band. 
 *   Otherwise, set it to 1.
 * 
 * See AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE; page 24 
 */
void SI4735::setSSBAudioBandwidth(byte AUDIOBW)

/*
 * Set the radio to SSB (LW/MW/SW) function. 
 * 
 * See AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE; pages 13 and 14
 * 
 * @param fromFreq minimum frequency for the band
 * @param toFreq maximum frequency for the band
 * @param initialFreq initial frequency 
 * @param step step used to go to the next channel  
 * @param usblsb SSB Upper Side Band (USB) and Lower Side Band (LSB) Selection; 
 *               value 2 (banary 10) = USB; 
 *               value 1 (banary 01) = LSB.   
 */
void SI4735::setSSB(unsigned fromFreq, unsigned toFreq, unsigned initialFreq, byte step, byte usblsb)