read TI TMP513 (all-in-one current, voltage, temp sensors) via I2C on raspberry pi

tmp513test.c

// read TI TMP512/TMP513 over I2C
// Jens Jensen AF5MI 2014

#include <wiringPi.h>
#include <wiringPiI2C.h>
#include <stdio.h>

// address of device - see datasheet, assumes A0 = SCL.
#define ADDR 0x5F

// current calibration register, see datasheet for calc
// I = (V_shunt * CalReg) / 4096
#define ICAL 40960  // R_shunt = 0.01 ohms, I in 0.1 mA
#define PR_mW  2    // PR multiplier per LSB to get mW result
#define CR_mA  0.1f //  CR multiplier per LSB to get mA result

#define CONFREG1 0b0000100110011111  // config reg 1 - see datasheet

#define CFGREG1 0x00 // shunt config
#define CFGREG2 0x01 // temp config
#define STATUSREG 0x02
#define SMBUSCTLREG 0x03
#define SVR  0x04 // shunt voltage result, 10uV LSB
#define BVR  0x05 // bus voltage result, 4mV LSB
#define PR   0x06  // power measurement result
#define CR   0x07  // current measurement result
#define LTR  0x08 // local temp result register
#define RTR1 0x09 // remote temp result 1 register
#define RTR2 0x0A // remote temp result 2 register
#define RTR3 0x0B // remote temp result 3 register
#define SCR  0x15 // shunt calibration register
#define RTS1_NFACTOR 0x16 // n-Factor 1 Register 16h (r/w)
#define RTS2_NFACTOR 0x17 // n-Factor 2 Register 17h (r/w)
#define RTS3_NFACTOR 0x18 // n-Factor 3 Register 18h (r/w)

int fd;

short getRegRaw ( int fd, int reg)
{
  short data = wiringPiI2CReadReg16(fd, reg);
  data = data >> 8 | ((data << 8) & 0xffff); // fix byte order
  return data;
}

float getTempC( int fd, int reg ) {
      // valid range: ±256C°
     int raw = getRegRaw(fd, reg);
     int diodeOpen = raw & 0x01;
     float tempC = (raw >> 3) * 0.0625;
     if (diodeOpen)
       tempC = -1024; // invalid reading
     return tempC;
}

float tempCtoF ( float tempC ) {
  float tempF = (tempC * 9.0) / 5.0 + 32.0;
  return tempF;
}

float busVoltageResult ( int bvraw ) {
  float busVoltage = (bvraw >> 3) * 0.004;
  return busVoltage;
}

int main (void)
{

  if((fd = wiringPiI2CSetup(ADDR)) < 0) {
    printf("I2CSetup Failed, %i\n", fd);
  }

  // init current calibration reg
  unsigned short caldata = ICAL >> 8 | ((ICAL << 8) & 0xffff); // fix byte order
  wiringPiI2CWriteReg16(fd, SCR, caldata);

  while (1) {
	  // get data
	  float ltrTempF = tempCtoF(getTempC(fd, LTR));
	  float rtr1TempF = tempCtoF(getTempC(fd, RTR1));
	  float rtr2TempF = tempCtoF(getTempC(fd, RTR2));
	  float rtr3TempF = tempCtoF(getTempC(fd, RTR3));
	  int bvrVal = getRegRaw(fd, BVR);
	  float busVoltage = busVoltageResult(bvrVal);
	  int svrVal = getRegRaw(fd, SVR);
	  int pwrVal = getRegRaw(fd, PR) * PR_mW;
	  int curVal = getRegRaw(fd, CR) * CR_mA;

	  printf("LTemp: %3.1f°F RT1: %3.1f°F RT2: %3.1f°F RT3: %3.1f°F\n",
		 ltrTempF, rtr1TempF, rtr2TempF, rtr3TempF);
	  printf("Vbus: %2.2f Vdc P: %3d mW I: %3d mA\n", 
		  busVoltage, pwrVal, curVal);

     printf("\n");     
     sleep(2);
  }

  close(fd);

}