// Define pins
const int trigPin = 2;  
const int echoPin = 4; 
const int redPin = 5;
const int greenPin = 12;
const int bluePin = 13;

// Other variables
long duration, cm;
int trigger = 0;

void setup() {
  // Initialize pins
  pinMode(trigPin, OUTPUT);  
  pinMode(echoPin, INPUT);  
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  
  Serial.begin(115200); // Use a higher baud rate for ESP32
}

void loop() {
  // Trigger ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Calculate duration and distance
  duration = pulseIn(echoPin, HIGH);
  cm = duration * 0.0343 / 2;

  // Handle LED based on distance
  if (cm >= 2 && cm <= 100) {
    trigger++;
    
    if (trigger >= 1 && trigger <= 9) {
      // Turn on red LED
      digitalWrite(redPin, HIGH);
      digitalWrite(greenPin, LOW);
      digitalWrite(bluePin, LOW);
    } else {
      // Reset trigger and turn on green LED
      trigger = 0;
      digitalWrite(redPin, LOW);
      digitalWrite(greenPin, HIGH);
      digitalWrite(bluePin, LOW);
    }
  } else {
    // Turn off all LEDs if out of range
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, LOW);
    digitalWrite(bluePin, LOW);
    trigger = 0; // Reset trigger if out of range
  }
  
  Serial.print("Distance: ");
  Serial.print(cm);
  Serial.println(" cm");
  delay(1000);  
}