#define LED_PIN 5
#define BUTTON_PIN 18

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  Serial.begin(115200);
}

void loop() {
  int buttonState = digitalRead(BUTTON_PIN);
  Serial.println(buttonState); // 1 = not pressed, 0 = pressed

  if (buttonState == LOW) { // Button pressed
    digitalWrite(LED_PIN, HIGH);
    delay(500);
    digitalWrite(LED_PIN, LOW);
    delay(500);
  } else { // Button not pressed
    digitalWrite(LED_PIN, LOW);
  }
}