void setup()
{
  pinMode(6,OUTPUT); 
  pinMode(7,INPUT);
  pinMode(5,OUTPUT);
  Serial.begin(9600);
}

void loop()
{
 digitalWrite(6,1);
 delay(1); 
 digitalWrite(6,0); 
 int sure=pulseIn(7,1); 
 int mesafe=(sure/2)/28.97; 
 Serial.print("Olculen mesafe:"); 
 Serial.println(mesafe); 
 delay(1); 
 if (mesafe<50)
 { 
  digitalWrite(5,1); 
   
   
 }  
   else
  {
  
  digitalWrite(5,0);
  
  
  
  } 
   
   
}