Angle calculation from Gyroscope

int gyro_X;
int gyro_Y;
int gyro_REF;
float diff_X;
int diff_Y;

double velocity_X;
double velocity_Y;
float rotate_X;
double rotate_Y;
double tot_X=0;
double tot_Y;
double tot;
int offangle_X;
int i=0;
int j=0;
double arr[5];
int angle_X()
{

  if(((diff_X<=6)&&(diff_X>=0))||((diff_X>=-6)&&(diff_X<0)))
    {
                 diff_X=0;
    }
    velocity_X=diff_X*500/1024;
    rotate_X=velocity_X*0.056;        

         if(i<=3)
         {
         arr[i]=rotate_X;
                         if(i=0)
                         {
                         tot_X=arr[0];
                         }
                         if(i=1)
                         {
                         tot_X=(arr[0]+arr[1]*2)/3;
                         }
                         if(i=2)
                         {
                         tot_X=(arr[0]+arr[1]*2+arr[2]*2)/5;
                         }
                         if(i=3)
                         {
                         tot_X=(arr[0]+arr[1]*2+arr[2]*2+arr[3])/6;
                         }
         }
         else
         {
         arr[i]=rotate_X;
          for(j=0;j<=3; j++)
            arr[j]=arr[j+1];
            tot_X=(arr[0]+arr[1]*2+arr[2]*2+arr[3])/6;
            i=3;
            
         }
         i=i+1;




    tot=tot+tot_X;

    offangle_X=tot;
    return offangle_X;
}

void main()
{
     trisa=0xff;
     UsART_Init(9600);
     while(1)
     {
     gyro_X=Adc_read(1);
     gyro_Y=Adc_Read(2);
     gyro_REF=Adc_Read(3);

     diff_X=gyro_X-gyro_REF;
     diff_Y=gyro_Y-gyro_REF;

     delay_ms(10);
     angle_X();

    // Usart_Write(rotate_X);
     Usart_Write(offangle_X);
     }
}