#include <Wire.h>

#define DS1624_ADDRESS 0x4F

int tempmsb = 0;
int templsb = 0;
int temp2 = 0;
float temperature = 0;

void setup() 
{ 
  Serial.begin(9600); 
  Wire.begin();
  delay(100);
  ds1624_config();
  delay(100);
  ds1624_startconvert();
  delay(1000);
} 

void ds1624_config() 
{ 
  // START CONDITION + ADDRESS + MODE
  Wire.beginTransmission(DS1624_ADDRESS);

  // SEND ACCESS CONFIG PROTOCOL
  Wire.send(0xAC);

  // SEND CONTINUOUS CONVERSION COMMAND
  Wire.send(0x00);

  // STOP CONDITION
  Wire.endTransmission();
}

void ds1624_startconvert() 
{ 
  // START CONDITION + ADDRESS + MODE
  Wire.beginTransmission(DS1624_ADDRESS);

  // SEND CONTINUOUS CONVERSION COMMAND
  Wire.send(0xEE);

  // STOP CONDITION
  Wire.endTransmission();
}

void ds1624_readtemp() 
{ 
  // START CONDITION + ADDRESS + MODE
  Wire.beginTransmission(DS1624_ADDRESS);

  // SEND READ TEMP COMMAND
  Wire.send(0xAA);

  // GET THE TEMP MSB AND LSB
  Wire.requestFrom(DS1624_ADDRESS, 2);
 
  if (Wire.available()) {
    tempmsb = Wire.receive();
  }
  
  if (Wire.available()) {
    templsb = Wire.receive();
  }

  temp2 = templsb >> 3;
  temperature = (float(tempmsb) + (float(temp2) * 0.03125));

  // STOP CONDITION
  Wire.endTransmission();
}

void printFloat(float value, int places) {
  // this is used to cast digits
  int digit;
  float tens = 0.1;
  int tenscount = 0;
  int i;
  float tempfloat = value;

    // make sure we round properly. this could use pow from <math.h>, but doesn't seem worth the import
  // if this rounding step isn't here, the value  54.321 prints as 54.3209

  // calculate rounding term d:   0.5/pow(10,places)  
  float d = 0.5;
  if (value < 0)
    d *= -1.0;
  // divide by ten for each decimal place
  for (i = 0; i < places; i++)
    d/= 10.0;    
  // this small addition, combined with truncation will round our values properly
  tempfloat +=  d;

  // first get value tens to be the large power of ten less than value
  // tenscount isn't necessary but it would be useful if you wanted to know after this how many chars the number will take

  if (value < 0)
    tempfloat *= -1.0;
  while ((tens * 10.0) <= tempfloat) {
    tens *= 10.0;
    tenscount += 1;
  }


  // write out the negative if needed
  if (value < 0)
    Serial.print('-');

  if (tenscount == 0)
    Serial.print(0, DEC);

  for (i=0; i< tenscount; i++) {
    digit = (int) (tempfloat/tens);
    Serial.print(digit, DEC);
    tempfloat = tempfloat - ((float)digit * tens);
    tens /= 10.0;
  }

  // if no places after decimal, stop now and return
  if (places <= 0)
    return;

  // otherwise, write the point and continue on
  Serial.print('.');  

  // now write out each decimal place by shifting digits one by one into the ones place and writing the truncated value
  for (i = 0; i < places; i++) {
    tempfloat *= 10.0;
    digit = (int) tempfloat;
    Serial.print(digit,DEC);  
    // once written, subtract off that digit
    tempfloat = tempfloat - (float) digit;
  }
}


void loop()
{
  ds1624_readtemp();

  Serial.print(" Temperature (deg C): "); 
  printFloat(temperature , 3);
  Serial.println();
  delay(1000);

}