Mesafe

/*

*/

void setup() {
  //put your setup code here, to run once:
    pinMode(9,OUTPUT);
    pinMode(8,INPUT);
    pinMode(4,OUTPUT);
}

void loop() {
    //put your main code here, to run repeatedly:
    long sure,mesafe;
    digitalWrite(9,LOW);
    delayMicroseconds(2);
    digitalWrite(9,HIGH);
    delayMicroseconds(10);
    digitalWrite(9,LOW);
    
    
    sure=pulseIn(8,HIGH);
    mesafe=(sure/2)29.1;
    
    if(mesafe<5)
    {
      digitalWrite(4,HIGH);  
    }
    else
    {
      digitalWrite(4,LOW);
    }
    delay(500);
    
}