const int relay=4;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(relay, OUTPUT);
}

void loop() {
  digitalWrite(relay, HIGH);
  Serial.println("BUZZER OFF");
  delay(1000);

  digitalWrite(relay, LOW);
  Serial.println("BUZZER ON");
  delay(1000);


}