#define SIZE_BUFFER     (16)
unsigned int measuring_value_buf[ SIZE_BUFFER + 1 ];
unsigned  int sum = 0;
unsigned char index = 0;
unsigned int Oversampling( unsigned int measuring_value )
 {  
  measuring_value_buf[ index ] = measuring_value;  
  sum += measuring_value;
  index++;  
  if( index > SIZE_BUFFER )
    index = 0;    
  if( sum >= measuring_value_buf[ index ] )
    sum -= measuring_value_buf[ index ];
  else
    sum = 0;
  return (unsigned int)(sum >> 2);
 }
////////////////// 
C_task main( void )	 
 {
  unsigned char q;  
  for(q=0; q<20; q++ )
    printf("%d     %d\n", q,Oversampling( 100 )); //UP
  for(q=0; q<20; q++ )
    printf("%d     %d\n", q,Oversampling(  0  )); // DOWN
 }