#define ECHO_PIN 2
#define TRIG_PIN 3
#define led1 4
#define led2 5
#define led3 6
int jarak;
float durasi;

void setup() {
  Serial.begin (115200);
  pinMode (TRIG_PIN, OUTPUT );
  pinMode (ECHO_PIN, INPUT );
  pinMode (led1, OUTPUT );
  pinMode (led2, OUTPUT );
  pinMode (led3, OUTPUT );
}

void loop() {
  digitalWrite (TRIG_PIN, LOW );
  delayMicroseconds (2);
  digitalWrite(TRIG_PIN, HIGH );
delayMicroseconds (10);
digitalWrite(TRIG_PIN, LOW );
durasi = pulseIn (ECHO_PIN, HIGH );
jarak = durasi * 0.034 / 2;
Serial.print ("jarak");
Serial.println(jarak);
if (jarak >70){
  digitalWrite (led1, LOW );
  digitalWrite (led2, HIGH );
  digitalWrite(led3, LOW);
}
  if(jarak <70){
  digitalWrite(led3, HIGH);
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
}
if(jarak <50){
  digitalWrite(led2, LOW);
  digitalWrite(led1, HIGH);
  digitalWrite(led3, LOW);
}
}