// Define the GPIO pins for your four LEDs
// You can change these to any suitable digital GPIO pin on your ESP32 board.
// Avoid pins used for specific functions like TX/RX (GPIO1, GPIO3) or strapping pins during boot.
const int ledPin1 = 16; // Example: Connecting the first LED to ESP32's GPIO 16
const int ledPin2 = 17; // Example: Connecting the second LED to ESP32's GPIO 17
const int ledPin3 = 4;  // Example: Connecting the third LED to ESP32's GPIO 4
const int ledPin4 = 2;  // Example: Connecting the fourth LED to ESP32's GPIO 2

// Define the blink interval (in milliseconds)
// This controls how long each state lasts before switching.
// 500 milliseconds = 0.5 seconds
const long blinkInterval = 500;

// You can create an array of pins for easier management, especially with more LEDs
const int ledPins[] = {ledPin1, ledPin2, ledPin3, ledPin4};
const int numberOfLeds = sizeof(ledPins) / sizeof(ledPins[0]);

void setup() {
  // Initialize the serial communication for debugging (optional but recommended)
    Serial.begin(115200);
      Serial.println("ESP32 Four LED Blink Program Started!");

        // Set all LED pins as OUTPUTs using a loop (more efficient for many LEDs)
          for (int i = 0; i < numberOfLeds; i++) {
              pinMode(ledPins[i], OUTPUT);
                  digitalWrite(ledPins[i], LOW); // Ensure all LEDs are off initially
                    }
                    }

                    void loop() {
                      // --- Chasing Light Pattern (one LED on at a time) ---
                        for (int i = 0; i < numberOfLeds; i++) {
                            Serial.print("Pattern: LED ");
                                Serial.print(i + 1);
                                    Serial.println(" ON");

                                        // Turn off all LEDs first
                                            for (int j = 0; j < numberOfLeds; j++) {
                                                  digitalWrite(ledPins[j], LOW);
                                                      }

                                                          // Turn on the current LED in the sequence
                                                              digitalWrite(ledPins[i], HIGH);
                                                                  delay(blinkInterval);
                                                                    }

                                                                      // --- All ON, then All OFF Pattern ---
                                                                        Serial.println("Pattern: All LEDs ON");
                                                                          for (int i = 0; i < numberOfLeds; i++) {
                                                                              digitalWrite(ledPins[i], HIGH); // Turn all LEDs ON
                                                                                }
                                                                                  delay(blinkInterval * 2); // Stay on for a bit longer

                                                                                    Serial.println("Pattern: All LEDs OFF");
                                                                                      for (int i = 0; i < numberOfLeds; i++) {
                                                                                          digitalWrite(ledPins[i], LOW); // Turn all LEDs OFF
                                                                                            }
                                                                                              delay(blinkInterval);

                                                                                                // The loop() function will repeat these patterns indefinitely.
                                                                                                }