#define trig_pin A5
#define echo_pin A4
#define led_merah 13
#define led_kuning 10
#define led_hijau 11
#define buzzer_pin 4
int durasi = 0;
float jarak = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(trig_pin, OUTPUT);
  pinMode(echo_pin, INPUT);
  pinMode(led_merah, OUTPUT);
  pinMode(led_kuning, OUTPUT);
  pinMode(led_hijau, OUTPUT);
  pinMode(buzzer_pin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  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;

  if(jarak > 197.31 && jarak < 396) {           //jika jarak di atas 2 meter
    digitalWrite(led_hijau, HIGH);
    digitalWrite(led_kuning, LOW);
    digitalWrite(led_merah, LOW); 
    digitalWrite(buzzer_pin, LOW);
    noTone(buzzer_pin);
  }else if(jarak > 98.62 && jarak < 197) {      //jika jarak di atas 1 meter
    digitalWrite(led_hijau, LOW);
    digitalWrite(led_kuning, HIGH);
    digitalWrite(led_merah, LOW);
    digitalWrite(buzzer_pin, LOW);
    noTone(buzzer_pin);
  }else if (jarak > 2.01 && jarak < 98) {       //jika jarak di bawah 1 meter
    digitalWrite(led_hijau, LOW);
    digitalWrite(led_kuning, LOW);
    digitalWrite(led_merah, HIGH);
    tone(buzzer_pin, 150);
    delay(100);
    noTone(buzzer_pin);
    delay(100);
  }
}