// NAMA : Muhammad Davin Sea
// KELAS : 5C
// NPM : 213510122
// Nama Project : sistem pengukuran jarak menggunakan sensor ultrasonic, 3 lampu LED

#define trigPin  2
#define echoPin    4
#define led_yellow 12 // LED 2
#define led_green 13 // LED 3
#define led_red 14 // LED 1

long duration;
float distance;

void setup() {
    pinMode (led_yellow, OUTPUT);
    pinMode (led_green, OUTPUT);
    pinMode (led_red, OUTPUT);
    pinMode (echoPin, INPUT);
    pinMode (trigPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(1);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(1);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin,HIGH);
  distance = duration * 0.034 / 2;

  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");
 
  
   if (distance>200) {
    digitalWrite(led_red, HIGH);  // LED 1 nyala
    digitalWrite(led_yellow, HIGH);  // LED 2 nyala
    digitalWrite(led_green, HIGH);  // LED 3 nyala

     } else if (distance>100) {
    digitalWrite(led_red, LOW);  // LED 1 mati
    digitalWrite(led_yellow, HIGH);  // LED 2 nyala
    digitalWrite(led_green, HIGH); // LED 3 nyala

  } else if(distance>50) {
    digitalWrite(led_red, LOW); // LED 1 mati
    digitalWrite(led_yellow, LOW); // LED 2 mati
    digitalWrite(led_green, HIGH);  // LED 3 nyala

  } else {
    digitalWrite(led_red, LOW); // LED 1 mati
    digitalWrite(led_yellow, LOW); // LED 2 mati
    digitalWrite(led_green, LOW); // LED 3 mati
  }
  
  delay(100);
}