void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(D19, OUTPUT);
  
}

void loop() {
 
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
digitalWrite(D19, HIGH);
delay(100);
digitalWrite(D19, LOW);
}