// Step 1: Define constants for LED pins
const int GREEN_LED_PIN = 17;  // GPIO 17 for Green LED
const int YELLOW_LED_PIN = 18; // GPIO 18 for Yellow LED
const int RED_LED_PIN = 19;    // GPIO 19 for Red LED

// Step 2: The setup() function runs once when the ESP32 starts
void setup() {
  // Initialize serial communication at 115200 baud (optional for debugging)
  Serial.begin(115200);

  // Step 3: Configure LED pins as OUTPUT
  pinMode(GREEN_LED_PIN, OUTPUT);   // Set Green LED pin as output
  pinMode(YELLOW_LED_PIN, OUTPUT);  // Set Yellow LED pin as output
  pinMode(RED_LED_PIN, OUTPUT);     // Set Red LED pin as output
}

// Step 4: The loop() function runs continuously after setup()
void loop() {
  // Blink the Green LED
  Serial.println("Green LED ON");         // Print status to Serial Monitor
  digitalWrite(GREEN_LED_PIN, HIGH);      // Turn on Green LED
  delay(3000);                            // Wait for 3 seconds
  digitalWrite(GREEN_LED_PIN, LOW);       // Turn off Green LED
  delay(500);                             // Short delay before next LED

  // Blink the Yellow LED
  Serial.println("Yellow LED ON");        // Print status to Serial Monitor
  digitalWrite(YELLOW_LED_PIN, HIGH);     // Turn on Yellow LED
  delay(3000);                            // Wait for 3 seconds
  digitalWrite(YELLOW_LED_PIN, LOW);      // Turn off Yellow LED
  delay(500);                             // Short delay before next LED

  // Blink the Red LED
  Serial.println("Red LED ON");           // Print status to Serial Monitor
  digitalWrite(RED_LED_PIN, HIGH);        // Turn on Red LED
  delay(3000);                            // Wait for 3 seconds
  digitalWrite(RED_LED_PIN, LOW);         // Turn off Red LED
  delay(500);                             // Short delay before repeating the loop
}