// Define the GPIO pins for the LEDs
const int ledPin1 = 2; // Change to the GPIO pin connected to the first LED
const int ledPin2 = 4; // Change to the GPIO pin connected to the second LED
const int ledPin3 = 5; // Change to the GPIO pin connected to the third LED

void setup() {
  // Initialize the GPIO pins as outputs
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
}

void loop() {
  // Turn on the first LED
  digitalWrite(ledPin1, HIGH);
  // Turn off the second and third LEDs
  digitalWrite(ledPin2, LOW);
  digitalWrite(ledPin3, LOW);
  // Wait for 500 milliseconds
  delay(500);
  
  // Turn off the first LED and turn on the second LED
  digitalWrite(ledPin1, LOW);
  digitalWrite(ledPin2, HIGH);
  // Wait for 500 milliseconds
  delay(500);
  
  // Turn off the second LED and turn on the third LED
  digitalWrite(ledPin2, LOW);
  digitalWrite(ledPin3, HIGH);
  // Wait for 500 milliseconds
  delay(500);
  
  // Turn off the third LED
  digitalWrite(ledPin3, LOW);
  // Wait for 500 milliseconds
  delay(500);
}