#define ECHO_PIN 2
#define TRIG_PIN 15

void setup() {

Serial.begin(115200);

pinMode(TRIG_PIN, OUTPUT);
pinMode(ECHO_PIN, INPUT);
pinMode(19, OUTPUT);
pinMode(18, OUTPUT);
pinMode(5, OUTPUT);
pinMode(4, OUTPUT);
pinMode(21, OUTPUT);
}

float readDistanceCM()
{
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}
void loop() 
{
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds (2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 /2;

  Serial.print("jarak");
  Serial.println(distance);
  bool isNear_by = distance > 50;
  digitalWrite(19, isNear_by);

bool is_Nearby = distance > 100;
  digitalWrite(18, is_Nearby);
  
    bool isN_earby = distance > 200;
  digitalWrite(5, isN_earby);
  
  bool isNe_arby = distance > 300;
  digitalWrite(4, isNe_arby);
  bool isNea_rby = distance < 300;
  tone(21,250,isNea_rby);
  
  delay(100);
}