int trig= 2;
int echo= 3;
long durasi, jarak;

int merah= 10;
int kuning= 9;
int hijau= 8;

void setup() {

pinMode(merah, OUTPUT);
pinMode(kuning, OUTPUT);
pinMode(hijau, OUTPUT);
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);

}

void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(8);
digitalWrite(trig, HIGH);
delayMicroseconds(8);
digitalWrite(trig, LOW);
delayMicroseconds(8);


durasi=pulseIn(echo, HIGH);
jarak=(durasi/2)/29.1;
Serial.println(jarak);

if(jarak  <50){
  digitalWrite(merah, HIGH);
  digitalWrite(kuning, LOW);
  digitalWrite(hijau, LOW);
}
else if(jarak== 120){
  digitalWrite(kuning, HIGH);
  digitalWrite(merah, LOW);
  digitalWrite(hijau, LOW);
}
else if(jarak ==110){
  digitalWrite(hijau, HIGH);
  digitalWrite(merah, LOW);
  digitalWrite(kuning, LOW);
}
else{
  digitalWrite(merah, LOW);
  digitalWrite(kuning, LOW);
  digitalWrite(hijau, LOW);
}


}