void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  const int trig =12;
  const int echo =14;
  int Distance;
  long duration;

  pinMode(21, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(18, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  digitalWrite(21, HIGH);
  digitalWrite(21, LOW);
  digitalWrite(19, HIGH);
  digitalWrite(19, LOW);
  digitalWrite(18, HIGH);
  digitalWrite(18,LOW);
  digitalWrite(5, HIGH);
  digitalWrite(5, LOW);
}