SI4844.h

/*
 * This is a library for the SI4844, BROADCAST ANALOG TUNING DIGITAL DISPLAY AM/FM/SW RADIO RECEIVER,
 * IC from Silicon Labs for the Arduino development environment.  
 * This library is intended to provide an easier interface for controlling the SI4844.
 * 
 * Author: Ricardo Lima Caratti (PU2CLR)
 * September, 2019
 */

#include <Arduino.h>
#include <Wire.h>

#define SI4844_ADDRESS 0x11

// English...: Si4844 Commands
// Portuguese: Comando usado no Si4844
// Reference.: Si48XX ATDD PROGRAMMING GUIDE, page 12
#define ATDD_POWER_DOWN 0x11
#define ATDD_POWER_UP 0xE1
#define ATDD_AUDIO_MODE 0xE2
#define GET_REV 0x10
#define ATDD_XOSCEN 0x80
#define ATDD_XOWAIT 0x40
#define ATDD_GET_STATUS 0xE0

#define SET_PROPERTY 0x12
#define RX_VOLUME 0x40
#define RX_BASS_TREBLE 0x4002

/* 
 * The structure below represents the four bytes response got by command ATDD_GET_STATUS
 * See PROGRAMMING GUIDE, pages 14 and 15
 */
typedef struct
{
  byte BCFG0 : 1;     // Bit 0
  byte BCFG1 : 1;     // bit 1
  byte STEREO : 1;    // bit 2
  byte STATION : 1;   // bit 3
  byte INFORDY : 1;   // bit 4
  byte HOSTPWRUP : 1; // bit 5
  byte HOSTRST : 1;   // bit 6
  byte CTS : 1;       // bit 7
  byte BANDIDX : 6;   // Form bit 0 to 5
  byte BANDMODE : 2;  // From bit 6 to 7
  byte d2 : 4;        // Frequency digit 2
  byte d1 : 4;        // Frequency digit 1
  byte d4 : 4;        // Frequency digit 4
  byte d3 : 4;        // frequency digit 3
} si4844_get_status;

/*
 * Uses a C language feature to represent two way for the 4 response bytes (status) sent by the ATDD_GET_STATUS.
 * It is needed to undertand the C language union concept.
 * See Si48XX ATDD PROGRAMMING GUIDE, pages 14 and 15 
*/
typedef union {
  si4844_get_status refined;
  byte raw[4];
} si4844_status_response;

/*
 * The structure below represents 9 response bytes sent by GET_REV command (STATUS and RESP1 to RESP8).
 * See Si48XX ATDD PROGRAMMING GUIDE, page 22.
 */
typedef struct
{
  byte RESERVED : 6; // Bit 0 to 5
  byte ERR : 1;      // bit 6
  byte CTS : 1;      // bit 2
  byte PN;           // Final 2 digits of Part Number (HEX).
  byte FWMAJOR;      // Firmware Major Revision (ASCII).
  byte FWMINOR;      // Firmware Minor Revision (ASCII).
  byte CMPMAJOR;     // Component Major Revision (ASCII).
  byte CMPMINOR;     // Component Minor Revision (ASCII).
  byte CHIPREV;      // Chip Revision (ASCII).
} si4844_firmware_info;

typedef union {
  si4844_firmware_info refined;
  byte raw[9];
} si4844_firmware_response;


/*
 * Structure for the command 0xE2 - ATDD_AUDIO_MODE
 * 
 */
 typedef  union {
    struct {
          byte AUDIOMODE : 2;
          byte FM_MONO : 1;
          byte ADJPT_ATTN : 1;
          byte ADJPT_STEO : 1;
          byte Reserved : 2;
          byte OPCODE : 1;
    } arg1;
    byte raw;
} si4844_audiomode;

typedef  union {
        struct {
          byte AUDIOMODE:2;
          byte FM_MONO:1;
          byte ADJPT_ATTN:1;
          byte ADJPT_STEO:1;
          byte Reserved:1;
          byte ERR:1;
          byte CTS:1;
        } status;
        byte raw;
} si4844_audiomode_status_response;

/* 
 * English:
 * Handling interruptions.
 * Whenever the status of the ATDD changes, a hardware interrupt is triggered. For example, when you move the tuner
 * potenciometer, the ATDD sends a signal to the Arduino pin (INTERRUPT_PIN). The same is true when the ATDD is capturing 
 * mono FM signal and has switched to stereo. The variable below indicates a change of the ATDD status. It will need to  
 * process some action (for example show on LCD this changes).   
 * 
 * Portuguese:
 * Manipulando Interrupções
 * Sempre que o estado do ATDD é modificado, uma interrupção de hardware é disparada. Esta interrupção é manipulada por
 * uma função implementada neste sketch, que nada mais faz que dizer que isso ocorreu para que algumas ações seja executadas adiante. 
 * Por exemplo: Qundo potenciômetro do sintonizador for girado, o ATDD envia um sinal para o pino do Arduino, no nosso caso, o
 * pino 2 do mini pro (INTERRUPT_PIN). Da mesma forma, quando um sinal de FM está sendo capturado no modo MONO e o sinal, por 
 * alguma razão, melhora e passa para FM, esta interrupção ocorre indicando que devemos apresentar FM Estéreo. 
 * 
 */

volatile static bool data_from_si4844;

static void interrupt_hundler()
{
 
  data_from_si4844 = true;
}


class SI4844
{

private:

  si4844_status_response status_response; 
  si4844_firmware_response firmware_response;
  unsigned int resetPin;
  unsigned int interruptPin;
  byte currentBand; 

  inline void setClockLow(void) { Wire.setClock(10000); };
  inline void setClockHigh(void) { Wire.setClock(50000); };
  inline void waitInterrupr(void);
  inline bool isClearToSend(void);
  inline void waitToSend(void);

  // SI4844 band description (FM = 0; AM = 1; SW = 2)
  const char *bandmode_table[3] = {"FM", "AM", "SW"};
  const char *stereo_indicator_table[2] = {"Off","On "};

  byte volume = 48;
  byte bassTreble = 4;   

public : 
  void setup(unsigned int, unsigned int, byte);
  void reset(void );
  void setBand(byte);
  
  void changeVolume(char);  // deprecated
  void volumeUp(void);
  void volumeDown(void);
  void setVolume(byte);
  void setBassTreble(byte bass_treble);
  void bassTrebleUp();
  void bassTrebleDown();
  void audioMute(byte value);
  void setAudioMute(bool on);

  si4844_audiomode_status_response setAudioMode(byte audiomode, byte fm_mono, byte adjpt_attn, byte adjpt_steo, byte opcode);

  si4844_status_response *getStatus(void);
  si4844_firmware_response *getFirmware(void);
  // customize the frequency range of a band
  void setCustomBand(byte, unsigned, unsigned, byte);

  void powerDown(void);
  void powerUp(void);

  float getFrequency(void);
  bool hasStatusChanged(void);
  void resetStatus(void);
  
  // return 0 = "FM mode"; 1 = "AM mode"; 2 = "SW mode".
  inline String getBandMode(){ return bandmode_table[status_response.refined.BANDMODE]; };
  // return char * "Off" or stereo "On"
  inline String getStereoIndicator(){ return stereo_indicator_table[status_response.refined.STATION]; };
  
  inline unsigned getStatusBCFG0() { return status_response.refined.BCFG0; };
  inline unsigned getStatusBCFG1() { return status_response.refined.BCFG1; };
  inline unsigned getStatusStereo() { return status_response.refined.STEREO; };
  inline unsigned getStatusStationIndicator() { return status_response.refined.STATION; };
  inline unsigned getStatusInformationReady() { return status_response.refined.INFORDY; };
  inline unsigned getStatusHostPowerUp() { return status_response.refined.HOSTPWRUP; };
  inline unsigned getStatusHostReset() { return status_response.refined.HOSTRST; };
  inline unsigned getStatusBandMode() { return status_response.refined.BANDMODE; };
  inline unsigned getStatusBandIndex() { return status_response.refined.BANDIDX; };
  inline unsigned getStatusCTS() { return status_response.refined.CTS; };


  inline unsigned getFirmwareReserved() { return firmware_response.refined.RESERVED; };
  inline unsigned getFirmwareErr() { return firmware_response.refined.ERR; };
  inline unsigned getFirmwareCTS() { return firmware_response.refined.CTS; };
  inline unsigned getFirmwarePartNumber() { return firmware_response.refined.PN; };
  inline unsigned getFirmwareMajorRevision() { return firmware_response.refined.FWMAJOR; };
  inline unsigned getFirmwareMinorRevision() { return firmware_response.refined.FWMINOR; };
  inline unsigned getFirmwareComponentMajorRevision() { return firmware_response.refined.CMPMAJOR; };
  inline unsigned getFirmwareComponentMinorRevision() { return firmware_response.refined.CMPMINOR; };
  inline unsigned getFirmwareChipRevision() { return firmware_response.refined.CHIPREV; };
};