#include <NewPing.h>
NewPing sensor(10,11,30);
const int led = 9;
int jarak;

void setup() {
  Serial.begin(9600);
  pinMode(led,OUTPUT);
  delay(50);
}

void loop() {
  jarak=sensor.ping_cm();
  if(jarak<=5){
    digitalWrite(led,HIGH);
    delay(50);
    digitalWrite(led,LOW);
    delay(50);  
  }else{
    digitalWrite(led,HIGH);
    delay(500);
    digitalWrite(led,LOW);
    delay(500); 
  }
  Serial.println(jarak);
  delay(1000);
}

Link library NewPing_v1.7

Source : Youtube Life Tech