ReadDataFromADXL345

  
  #include <Wire.h>
  
  #define DEVICE (0x53)    //ADXL345 device address
  #define TO_READ (6)        //num of bytes we are going to read each time (two bytes for each axis)
  
  byte buff[TO_READ] ;    //6 bytes buffer for saving data read from the device
  char str[512];                      //string buffer to transform data before sending it to the serial port
  
  void setup()
 {
   Wire.begin();        // join i2c bus (address optional for master)
   Serial.begin(9600);  // start serial for output
   
   //Turning on the ADXL345
   writeTo(DEVICE, 0x2D, 0);      
   writeTo(DEVICE, 0x2D, 16);
   writeTo(DEVICE, 0x2D, 8);
 }

    
  void loop()
  {
    int regAddress = 0x32;    //first axis-acceleration-data register on the ADXL345
    int x, y, z;
    
    readFrom(DEVICE, regAddress, TO_READ, buff); //read the acceleration data from the ADXL345
    
     //each axis reading comes in 10 bit resolution, ie 2 bytes.  Least Significat Byte first!!
     //thus we are converting both bytes in to one int
   x = (((int)buff[1]) << 8) | buff[0];   
   y = (((int)buff[3])<< 8) | buff[2];
   z = (((int)buff[5]) << 8) | buff[4];
   
   //we send the x y z values as a string to the serial port
   sprintf(str, "%d %d %d", x, y, z);  
   Serial.print(str);
   Serial.write(byte(10));
   
   //delay for 0.5 second for each loop
   delay(500);
 }

    
 void writeTo(int device, byte address, byte val) {
    Wire.beginTransmission(device); //start transmission to device 
    Wire.write(address);        // send register address
    Wire.write(val);        // send value to write
    Wire.endTransmission(); //end transmission
 }

    
  void readFrom(int device, byte address, int num, byte buff[]) {
    Wire.beginTransmission(device); //start transmission to device 
    Wire.write(address);        //sends address to read from
    Wire.endTransmission(); //end transmission
    
    Wire.beginTransmission(device); //start transmission to device (initiate again)
    Wire.requestFrom(device, num);    // request 6 bytes from device
    
    int i = 0;
   while(Wire.available())    //device may send less than requested (abnormal)
   { 
     buff[i] = Wire.read(); // receive a byte
     i++;
   }
   Wire.endTransmission(); //end transmission
 }