void setup() {
 
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(12, OUTPUT);
  pinMode(23, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(15, OUTPUT);
}

void loop() {
  tone(12,650);
  digitalWrite(23, HIGH);
  delay(500);
  digitalWrite(23, LOW);
  delay(500);
  tone(21,777);
  digitalWrite(19, HIGH);
  delay(500);
  digitalWrite(19, LOW);
  delay(500);

  
}