ds1631_i2c.c - PIC24 uC in Master mode to Maxim DS1631 Digital Thermometer using I2C

I2C Example: Demonstrates I2C functions by reading/writing from a Maxim DS1631 Digital Thermometer.

 
#include "pic24_all.h"
#include <stdio.h>

#define DS1631ADDR 0x90   //DS1631 address with all pins tied low
#define ACCESS_CONFIG 0xAC
#define START_CONVERT 0x51
#define READ_TEMP 0xAA

void writeConfigDS1631(uint8_t u8_i) {
  write2I2C1(DS1631ADDR, ACCESS_CONFIG, u8_i);
}

void startConversionDS1631() {
  write1I2C1(DS1631ADDR, START_CONVERT);
}

int16_t readTempDS1631() {
  uint8_t u8_lo, u8_hi;
  int16_t i16_temp;
  write1I2C1(DS1631ADDR, READ_TEMP);
  read2I2C1 (DS1631ADDR, &u8_hi, &u8_lo);
  i16_temp = u8_hi;
  return ((i16_temp<<8)|u8_lo);
}

int main (void) {
  int16_t i16_temp;
  float  f_tempC,f_tempF;
  configBasic(HELLO_MSG);
  configI2C1(400);            //configure I2C for 400 KHz
  writeConfigDS1631(0x0C);    //continuous conversion, 12-bit mode
  startConversionDS1631();    //start conversions
  while (1) {
    DELAY_MS(750);
    i16_temp = readTempDS1631();
    f_tempC = i16_temp;  //convert to floating point
    f_tempC = f_tempC/256;  //divide by precision
    f_tempF = f_tempC*9/5 + 32;
    printf("Temp is: 0x%0X, %4.4f (C), %4.4f (F)\n", i16_temp, (double) f_tempC, (double) f_tempF);
  }
}