#define ECHO_PIN 5
#define TRIG_PIN 4
#define LED_RED 8
#define LED_YELLOW 7
#define LED_GREEN 6

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(TRIG_PIN,OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

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

  if(distance <= 10){
    digitalWrite(LED_RED, HIGH);
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, LOW);
  }else if(distance < 50){
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, HIGH);
  }else{
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_GREEN, HIGH);
    digitalWrite(LED_YELLOW, LOW);
  }

  Serial.print("Jarak : ");
  Serial.print(distance);
  Serial.println("");
  delay(100);
}