File content as of revision 5:bc6f2d389038:

#include "mbed.h"
#include "SparkFun-Si4703.h"

Si4703_Breakout::Si4703_Breakout(PinName sdioPin, PinName sclkPin, PinName resetPin, Serial *pc)
{
  _resetPin = resetPin;
  _sdioPin = sdioPin;
  _sclkPin = sclkPin;

 this->pc = pc;
}

void Si4703_Breakout::powerOn()
{
    si4703_init();
}

void Si4703_Breakout::powerOff()
{
// a Minimal Power-Down Sequence - According To SI AN230 (rev. 0.9), p.13 - Table 4

readRegisters();
si4703_registers[POWERCFG] &= ~(1<<DMUTE); // 'Enable Mute'
updateRegisters();

readRegisters();
si4703_registers[POWERCFG] |= (1<<ENABLE); // 'Enable IC'
updateRegisters();

readRegisters();
si4703_registers[POWERCFG] |= (1<<DISABLE); // & 'Disable IC'
updateRegisters();

// Notice : This Does NOT Perform a Reset of The IC.
}

void Si4703_Breakout::setChannel(int channel)
{
  uint8_t ack;
  //Freq(MHz) = 0.1 (in Europe) * Channel + 87.5MHz
  //97.3 = 0.1 * Chan + 87.5
  //9.8 / 0.1 = 98
  int newChannel = channel * 10; //973 * 10 = 9730
  newChannel -= 8750; //9730 - 8750 = 980
  newChannel /= 10; //980 / 10 = 98

  //These steps come from AN230 page 20 rev 0.5
  readRegisters();
  si4703_registers[CHANNEL] &= 0xFE00; //Clear out the channel bits
  si4703_registers[CHANNEL] |= newChannel; //Mask in the new channel
  si4703_registers[CHANNEL] |= (1<<TUNE); //Set the TUNE bit to start
  updateRegisters();

  wait_ms(60); //Wait 60ms - you can use or skip this delay

  //Poll to see if STC is set
  while(1) {
    ack = readRegisters();
    wait_ms(1); // Just In Case...
    if (( (si4703_registers[STATUSRSSI] & (1<<STC)) != 0) || (ack != SUCCESS)) break; //Tuning complete! (or FAILED)
  }

  readRegisters();
  si4703_registers[CHANNEL] &= ~(1<<TUNE); //Clear the tune after a tune has completed
  updateRegisters();

  //Wait for the si4703 to clear the STC as well
  while(1) {
    ack = readRegisters();
    wait_ms(1); // Just In Case...
    if (( (si4703_registers[STATUSRSSI] & (1<<STC)) == 0) || (ack != SUCCESS)) break; //Tuning complete! (or FAILED)
  }
}

int Si4703_Breakout::seekUp()
{
	return seek(SEEK_UP);
}

int Si4703_Breakout::seekDown()
{
	return seek(SEEK_DOWN);
}

void Si4703_Breakout::setVolume(int volume)
{
  readRegisters(); //Read the current register set
  if(volume < 0) volume = 0;
  if (volume > 15) volume = 15;
  si4703_registers[SYSCONFIG2] &= 0xFFF0; //Clear volume bits
  si4703_registers[SYSCONFIG2] |= volume; //Set new volume
  updateRegisters(); //Update
}

uint8_t Si4703_Breakout::getVolume()
{
  readRegisters(); //Read the current register set

  return (si4703_registers[SYSCONFIG2] & 0x000F);
}

/*
void Si4703_Breakout::readRDS(char* buffer, long timeout)
{ 
	long endTime = millis() + timeout;
  boolean completed[] = {false, false, false, false};
  int completedCount = 0;
  while(completedCount < 4 && millis() < endTime) {
	readRegisters();
	if(si4703_registers[STATUSRSSI] & (1<<RDSR)){
		// ls 2 bits of B determine the 4 letter pairs
		// once we have a full set return
		// if you get nothing after 20 readings return with empty string
	  uint16_t b = si4703_registers[RDSB];
	  int index = b & 0x03;
	  if (! completed[index] && b < 500)
	  {
		completed[index] = true;
		completedCount ++;
	  	char Dh = (si4703_registers[RDSD] & 0xFF00) >> 8;
      	char Dl = (si4703_registers[RDSD] & 0x00FF);
		buffer[index * 2] = Dh;
		buffer[index * 2 +1] = Dl;
		// Serial.print(si4703_registers[RDSD]); Serial.print(" ");
		// Serial.print(index);Serial.print(" ");
		// Serial.write(Dh);
		// Serial.write(Dl);
		// Serial.println();
      }
      delay(40); //Wait for the RDS bit to clear
	}
	else {
	  delay(30); //From AN230, using the polling method 40ms should be sufficient amount of time between checks
	}
  }
	if (millis() >= endTime) {
		buffer[0] ='\0';
		return;
	}

  buffer[8] = '\0';
}
*/



//To get the Si4703 inito 2-wire mode, SEN needs to be high and SDIO needs to be low after a reset
//The breakout board has SEN pulled high, but also has SDIO pulled high. Therefore, after a normal power up
//The Si4703 will be in an unknown state. RST must be controlled
void Si4703_Breakout::si4703_init() 
{
  _reset_ = new DigitalOut(_resetPin);
  _sdio_ = new DigitalOut(_sdioPin);

  _sdio_->write(0); //A low SDIO indicates a 2-wire interface
  _reset_->write(0); //Put Si4703 into reset
  wait_ms(1); //Some delays while we allow pins to settle
  _reset_->write(1); //Bring Si4703 out of reset with SDIO set to low and SEN pulled high with on-board resistor
  wait_ms(1); //Allow Si4703 to come out of reset

  //Now that the unit is reset and I2C inteface mode, we need to begin I2C
  i2c_ = new I2C(_sdioPin, _sclkPin);
  i2c_->frequency(100000);
  ///

  readRegisters(); //Read the current register set
  si4703_registers[0x07] = 0x8100; //Enable the oscillator, from AN230 page 9, rev 0.61 (works)
  updateRegisters(); //Update

  wait_ms(500); //Wait for clock to settle - from AN230 page 9

  readRegisters(); //Read the current register set
  si4703_registers[POWERCFG] = 0x4001; //Enable the IC
  //  si4703_registers[POWERCFG] |= (1<<SMUTE) | (1<<DMUTE); //Disable Mute, disable softmute
  si4703_registers[SYSCONFIG1] |= (1<<RDS); //Enable RDS

  si4703_registers[SYSCONFIG1] |= (1<<DE); //50μS Europe setup
  si4703_registers[SYSCONFIG2] |= (1<<SPACE0); //100kHz channel spacing for Europe

  si4703_registers[SYSCONFIG2] &= 0xFFF0; //Clear volume bits
  si4703_registers[SYSCONFIG2] |= 0x0001; //Set volume to lowest

  // SI AN230 page 40 - Table 23 ('Good Quality Stations Only' Settings)
  si4703_registers[SYSCONFIG2] |= (0xC<<SEEKTH);
  si4703_registers[SYSCONFIG3] |= (0x7<<SKSNR);
  si4703_registers[SYSCONFIG3] |= (0xF<<SKCNT);
  ///
  updateRegisters(); //Update

  wait_ms(110); //Max powerup time, from datasheet page 13
  
}

//Read the entire register control set from 0x00 to 0x0F
uint8_t Si4703_Breakout::readRegisters(){

  //Si4703 begins reading from register upper register of 0x0A and reads to 0x0F, then loops to 0x00.
//  Wire.requestFrom(SI4703, 32); //We want to read the entire register set from 0x0A to 0x09 = 32 uint8_ts.
    char data[32];
    uint8_t ack = i2c_->read(SI4703, data, 32); //Read in these 32 uint8_ts

  if (ack != 0) { //We have a problem! 
    return(FAIL);
  }

//Remember, register 0x0A comes in first so we have to shuffle the array around a bit
	for (int y=0; y<6; y++)
		{
			si4703_registers[0x0A+y] = 0;
			si4703_registers[0x0A+y] = data[(y*2)+1];
			si4703_registers[0x0A+y] |= (data[(y*2)] << 8);
		}

	for (int y=0; y<10; y++)
		{
			si4703_registers[y] = 0;
			si4703_registers[y] = data[(12)+(y*2)+1];
			si4703_registers[y] |= (data[(12)+(y*2)] << 8);
		}
//We're done!
///
  return(SUCCESS);
}

//Write the current 9 control registers (0x02 to 0x07) to the Si4703
//It's a little weird, you don't write an I2C address
//The Si4703 assumes you are writing to 0x02 first, then increments
uint8_t Si4703_Breakout::updateRegisters() {

  char data[12];

  //First we send the 0x02 to 0x07 control registers
  //In general, we should not write to registers 0x08 and 0x09
  for(int regSpot = 0x02 ; regSpot < 0x08 ; regSpot++) {
    data[(regSpot-2)*2] = si4703_registers[regSpot] >> 8;
    data[((regSpot-2)*2)+1] = si4703_registers[regSpot] & 0x00FF;
  }

  uint8_t ack = i2c_->write(SI4703, data, 12);  // a write command automatically begins with register 0x02 so no need to send a write-to address

  if(ack != 0) { //We have a problem! 
    return(FAIL);
  }

  return(SUCCESS);
}

//Returns The Value of a Register
uint16_t Si4703_Breakout::getRegister(uint8_t regNum)
{
  readRegisters();
  return si4703_registers[regNum];
// No Error Status Checking
}

//Seeks out the next available station
//Returns the freq if it made it
//Returns zero if failed
int Si4703_Breakout::seek(bool seekDirection){
  uint8_t ack;
  readRegisters();
  //Set seek mode wrap bit
  si4703_registers[POWERCFG] |= (1<<SKMODE); //Disallow wrap - if you disallow wrap, you may want to tune to 87.5 first
  //si4703_registers[POWERCFG] &= ~(1<<SKMODE); //Allow wrap
  if(seekDirection == SEEK_DOWN) si4703_registers[POWERCFG] &= ~(1<<SEEKUP); //Seek down is the default upon reset
  else si4703_registers[POWERCFG] |= 1<<SEEKUP; //Set the bit to seek up

  si4703_registers[POWERCFG] |= (1<<SEEK); //Start seek
  updateRegisters(); //Seeking will now start

  //Poll to see if STC is set
  while(1) {
    ack = readRegisters();
    wait_ms(1); // Just In Case...
    if (((si4703_registers[STATUSRSSI] & (1<<STC)) != 0) || (ack != SUCCESS)) break; //Tuning complete! (or FAILED)
  }

  readRegisters();
  int valueSFBL = si4703_registers[STATUSRSSI] & (1<<SFBL); //Store the value of SFBL
  si4703_registers[POWERCFG] &= ~(1<<SEEK); //Clear the seek bit after seek has completed
  updateRegisters();

  //Wait for the si4703 to clear the STC as well
  while(1) {
    ack = readRegisters();
    wait_ms(1); // Just In Case...   
    if (((si4703_registers[STATUSRSSI] & (1<<STC)) == 0) || (ack != SUCCESS)) break; //Tuning complete! (or FAILED)
  }

  if(valueSFBL) { //The bit was set indicating we hit a band limit or failed to find a station
    return(0);
  }
return getChannel();
}

//Reads the current channel from READCHAN
//Returns a number like 973 for 97.3MHz
int Si4703_Breakout::getChannel() {
  readRegisters();
  int channel = (si4703_registers[READCHAN] & 0x03FF); //Mask out everything but the lower 10 bits
  //Freq(MHz) = 0.100(in Europe) * Channel + 87.5MHz
  //X = 0.1 * Chan + 87.5
  channel += 875; //98 + 875 = 973 ( for 97.3 MHz )
  return(channel);
}

void Si4703_Breakout::printRegs() {
  readRegisters();
  for (int x=0; x<16; x++) { pc->printf("Reg# 0x%X = 0x%X\r\n",x,si4703_registers[x]); wait_ms(1); }
}