#define LED_PIN 2

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  for(int i=1;i<=5;i++){
    digitalWrite(LED_PIN, HIGH);
    delay(1000);
    digitalWrite(LED_PIN, LOW);
    delay(1000*i);
  }
  for(int i=5;i>=0;i--){
    digitalWrite(LED_PIN, HIGH);
    delay(1000);
    digitalWrite(LED_PIN, LOW);
    delay(1000*i);
  }
}