#define BUTTON_PIN 7    // Button connected to pin 7
#define LED_PIN 13      // LED connected to pin 13

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);  // Button with internal pull-up resistor
  pinMode(LED_PIN, OUTPUT);           // Set LED pin as output
  Serial.begin(9600);                 // Start serial communication
}

void loop() {
  if (Serial.available()) {
    char command = Serial.read();
    Serial.print("Received: ");
    Serial.println(command);

    if (command == 'E') {
      digitalWrite(LED_PIN, HIGH);  // Turn on LED
      delay(500);                    // Keep LED on for 500ms
      digitalWrite(LED_PIN, LOW);   // Turn off LED
      delay(500);                    // Keep it off for 500ms
    }
  }

  if (digitalRead(BUTTON_PIN) == LOW) {  // Button is pressed
    Serial.println("A");    // Send 'A' to ESP32
    delay(200);             // Debounce delay
  }
}