/*
  DS1307.cpp - library for DS1307 rtc
  Created by matt.joyce@gmail.com, December, 2007.
  Released into the public domain.
  
  scjurgen@yahoo.com: 
   added ctrl register function (set_ctrlreg) to enable clock out with 1Hz, 4Khz, 8Khz or 32Khz (useful with pin 2 or 3 on arduino for precise clock interrupt )
*/


extern "C" {
#include <../Wire/Wire.h>
}

#include "DS1307.h"

DS1307::DS1307()
{
  Wire.begin();
}

DS1307 RTC=DS1307();

// PRIVATE FUNCTIONS

// Aquire data from the RTC chip in BCD format
// refresh the buffer
void DS1307::read_rtc(void)
{
  // use the Wire lib to connect to tho rtc
  // reset the register pointer to zero
  Wire.beginTransmission(DS1307_CTRL_ID);
  Wire.send(0x00);
  Wire.endTransmission();

  // request the 7 bytes of data    (secs, min, hr, dow, date. mth, yr)
  Wire.requestFrom(DS1307_CTRL_ID, 7);
  for(int i=0; i<7; i++)
  {
    // store data in raw bcd format
    rtc_bcd[i]=Wire.receive();
  }
}

// update the data on the IC from the bcd formatted data in the buffer
void DS1307::save_rtc(void)
{
  Wire.beginTransmission(DS1307_CTRL_ID);
  Wire.send(0x00); // reset register pointer
  for(int i=0; i<7; i++)
  {
    Wire.send(rtc_bcd[i]);
  }
  Wire.endTransmission();
}


// PUBLIC FUNCTIONS
void DS1307::get(int *rtc, boolean refresh)   // Aquire data from buffer and convert to int, refresh buffer if required
{
  if(refresh) read_rtc();
  for(int i=0;i<7;i++)  // cycle through each component, create array of data
  {
        rtc[i]=get(i, 0);
  }
}

int DS1307::get(int c, boolean refresh)  // aquire individual RTC item from buffer, return as int, refresh buffer if required
{
  if(refresh) read_rtc();
  int v=-1;
  switch(c)
  {
 
  case DS1307_SEC:
    v=(10*((rtc_bcd[DS1307_SEC] & DS1307_HI_SEC)>>4))+(rtc_bcd[DS1307_SEC] & DS1307_LO_BCD);
        break;
  case DS1307_MIN:
    v=(10*((rtc_bcd[DS1307_MIN] & DS1307_HI_MIN)>>4))+(rtc_bcd[DS1307_MIN] & DS1307_LO_BCD);
        break;
  case DS1307_HR:
    v=(10*((rtc_bcd[DS1307_HR] & DS1307_HI_HR)>>4))+(rtc_bcd[DS1307_HR] & DS1307_LO_BCD);
        break;
  case DS1307_DOW:
    v=rtc_bcd[DS1307_DOW] & DS1307_LO_DOW;
        break;
  case DS1307_DATE:
    v=(10*((rtc_bcd[DS1307_DATE] & DS1307_HI_DATE)>>4))+(rtc_bcd[DS1307_DATE] & DS1307_LO_BCD);
        break;
  case DS1307_MTH:
    v=(10*((rtc_bcd[DS1307_MTH] & DS1307_HI_MTH)>>4))+(rtc_bcd[DS1307_MTH] & DS1307_LO_BCD);
        break;
  case DS1307_YR:
    v=(10*((rtc_bcd[DS1307_YR] & DS1307_HI_YR)>>4))+(rtc_bcd[DS1307_YR] & DS1307_LO_BCD)+DS1307_BASE_YR;
        break;
  } // end switch
  return v;
}

void DS1307::set(int c, int v)  // Update buffer, then update the chip
{
  switch(c)
  {
  case DS1307_SEC:
    if(v<60 && v>-1)
    {
      //preserve existing clock state (running/stopped)
      int state=rtc_bcd[DS1307_SEC] & DS1307_CLOCKHALT;
      rtc_bcd[DS1307_SEC]=state | (((v / 10)<<4) + (v % 10));
    }
    break;
  case DS1307_MIN:
    if(v<60 && v>-1)
    {
      rtc_bcd[DS1307_MIN]=((v / 10)<<4) + (v % 10);
    }
    break;
  case DS1307_HR:
   // TODO : AM/PM  12HR/24HR currently 24 hour mode
    if(v<24 && v>-1)
    {
      rtc_bcd[DS1307_HR]=((v / 10)<<4) + (v % 10);
    }
    break;
  case DS1307_DOW:
    if(v<8 && v>-1)
    {
      rtc_bcd[DS1307_DOW]=v;
    }
    break;
  case DS1307_DATE:
    if(v<32 && v>-1)
    {
      rtc_bcd[DS1307_DATE]=((v / 10)<<4) + (v % 10);
    }
    break;
  case DS1307_MTH:
    if(v<13 && v>-1)
    {
      rtc_bcd[DS1307_MTH]=((v / 10)<<4) + (v % 10);
    }
    break;
  case DS1307_YR:
    if (v >=2000)
    	v-=2000;
    if(v<99 && v>-1)
    {
      rtc_bcd[DS1307_YR]=((v / 10)<<4) + (v % 10);
    }
    break;
  } // end switch
  save_rtc();
}

int DS1307::min_of_day(boolean refresh)
{
    // return minutes of day  (0-1440)
    if(refresh) read_rtc();
    int MoD=(get(DS1307_HR,false)*60)+get(DS1307_MIN,false);
    return MoD;
}

void DS1307::stop(void)
{
    // set the ClockHalt bit high to stop the rtc
    // this bit is part of the seconds byte
    rtc_bcd[DS1307_SEC]=rtc_bcd[DS1307_SEC] | DS1307_CLOCKHALT;
    save_rtc();
}

void DS1307::start(void)
{
    // unset the ClockHalt bit to start the rtc
    // TODO : preserve existing seconds, now just preserving if previously read
    rtc_bcd[DS1307_SEC]&=~DS1307_CLOCKHALT;
    save_rtc();
}

void DS1307::get_sram_data(byte *sram_data)
{
  // set the register to the sram area and read 56 bytes
  Wire.beginTransmission(DS1307_CTRL_ID);
  Wire.send(DS1307_DATASTART);
  Wire.endTransmission();
 
  for(int i=0;i<56;i++)
  {
    Wire.requestFrom(DS1307_CTRL_ID, 56);
    sram_data[i]=Wire.receive();
  }
}

void DS1307::set_sram_data(byte *sram_data)
{
	// set the register to the sram area and save 56 bytes
	Wire.beginTransmission(DS1307_CTRL_ID);
	Wire.send(DS1307_DATASTART);

	for(int i=0;i<56;i++)
	{
		Wire.send(sram_data[i]);
	}
	Wire.endTransmission();
}

byte DS1307::getSingleReg(byte reg)
{
  // use the Wire lib to connect to tho rtc
  // reset the register pointer to zero
  Wire.beginTransmission(DS1307_CTRL_ID);
  Wire.send(reg);
  Wire.endTransmission();

  // request the 7 bytes of data    (secs, min, hr, dow, date. mth, yr)
  Wire.requestFrom(DS1307_CTRL_ID, 1);
  byte val = Wire.receive();
  return val;
}

void DS1307::setSingleReg(byte reg, byte b)
{
	Wire.beginTransmission(DS1307_CTRL_ID);
    Wire.send(reg);
    Wire.send(b);
    Wire.endTransmission();  
}


// set ctrl register for Clock out (see Macros: DS1307_1HZ etc.)
void DS1307::set_ctrlreg(byte b)
{
	byte secs=getSingleReg(DS1307_HI_SEC);
	setSingleReg(DS1307_HI_SEC,secs|DS1307_CLOCKHALT);
	setSingleReg(DS1307_CTRLREG,b);	
	setSingleReg(DS1307_HI_SEC,secs);
}

byte DS1307::get_sram_byte(int p)
{
    // set the register to a specific the sram location and read a single byte
    Wire.beginTransmission(DS1307_CTRL_ID);
    Wire.send(DS1307_DATASTART+p);
    Wire.endTransmission();  
    Wire.requestFrom(DS1307_CTRL_ID, 1);
    return Wire.receive();
}

void DS1307::set_sram_byte(byte b, int p)
{
    // set the register to a specific the sram location and save a single byte
    Wire.beginTransmission(DS1307_CTRL_ID);
    Wire.send(DS1307_DATASTART+p);
    Wire.send(b);
    Wire.endTransmission();  
}