#include <Servo.h>
  #define Register_ID 0
  #define Register_2D 0x2D
  #define Register_X0 0x32
  #define Register_X1 0x33
  #define Register_Y0 0x34
  #define Register_Y1 0x35
  #define Register_Z0 0x36
  #define Register_Z1 0x37

  #include <Wire.h>

  int ADXAddress = 0xA7 >> 1; // the default 7-bit slave address
  int reading = 0;
  int val=0;
  int X0,X1,X_out;
  int Y0,Y1,Y_out;
  int Z1,Z0,Z_out;
  double Xg,Yg,Zg;
  double angle=0;
  
  Servo servo;

void setup()
{
  Wire.begin(); 
  Serial.begin(9600); 
  servo.attach(2);
  delay(100);
  // enable to measute g data
  Wire.beginTransmission(ADXAddress);
  Wire.send(Register_2D);
  Wire.send(8); //measuring enable
  Wire.endTransmission(); // stop transmitting
}

void loop()
{
//--------------X
  Wire.beginTransmission(ADXAddress); // transmit to device
   Wire.send(Register_X0);
  Wire.send(Register_X1);
  Wire.endTransmission();
   Wire.requestFrom(ADXAddress,2); 
  if(Wire.available()<=2) 
   {
    X0 = Wire.receive();
     X1 = Wire.receive(); 
     X1=X1<<8;
     X_out=X0+X1; 
   }

//------------------Y
  Wire.beginTransmission(ADXAddress); // transmit to device
  Wire.send(Register_Y0);
  Wire.send(Register_Y1);
  Wire.endTransmission();
  Wire.requestFrom(ADXAddress,2); 
   if(Wire.available()<=2) 
  {
     Y0 = Wire.receive();
     Y1 = Wire.receive(); 
     Y1=Y1<<8;
     Y_out=Y0+Y1;
  }
  //------------------Z
   Wire.beginTransmission(ADXAddress); // transmit to device
   Wire.send(Register_Z0);
  Wire.send(Register_Z1);
   Wire.endTransmission();
   Wire.requestFrom(ADXAddress,2); 
  if(Wire.available()<=2) 
  {
    Z0 = Wire.receive();
    Z1 = Wire.receive(); 
    Z1=Z1<<8;
    Z_out=Z0+Z1;
  }
//
  Xg=X_out/256.0;
  Yg=Y_out/256.0;
  Zg=Z_out/256.0;
  angle = acos(Xg/sqrt(pow(Xg,2)+pow(Yg,2)));
  angle = (angle/3.14)*180;
  Serial.println(angle);
  servo.write(angle);
 // Serial.print("X= ");
 // Serial.print(Xg);
 // Serial.print(" ");
 //  Serial.print("Y= ");
 //  Serial.print(Yg);
 //  Serial.print(" ");
 // Serial.print("Z= ");
 //  Serial.print(Zg);
 // Serial.println(" ");
 // delay(1000);
  }