求教！！有关Arduino和传感器的IIC通讯（MLX90615）

#include <i2cmaster.h>


void setup(){
        Serial.begin(9600);
        Serial.println("Setup...");
       
        i2c_init(); //Initialise the i2c bus
       
}

void loop(){
    int dev = 0x5B<<1;
    int data_low = 0;
    int data_high = 0;
    int pec = 0;
   
    i2c_start_wait(dev+I2C_WRITE);
    i2c_write(0x07);
   
    // read
    i2c_rep_start(dev+I2C_READ);
    data_low = i2c_readAck(); //Read 1 byte and then send ack
    data_high = i2c_readAck(); //Read 1 byte and then send ack
    pec = i2c_readNak();
    i2c_stop();
   
    //This converts high and low bytes together and processes temperature, MSB is a error bit and is ignored for temps
    double tempFactor = 0.02; // 0.02 degrees per LSB (measurement resolution of the MLX90614)
    double tempData = 0x0000; // zero out the data
    int frac; // data past the decimal point
   
    // This masks off the error bit of the high byte, then moves it left 8 bits and adds the low byte.
    tempData = (double)(((data_high & 0x007F) << 8) + data_low);
    tempData = (tempData * tempFactor)-0.01;
   
    float celcius = tempData - 273.15;
    float fahrenheit = (celcius*1.8) + 32;

    Serial.print("Celcius: ");
    Serial.println(celcius);


    delay(1000); // wait a second before printing again
}