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

  // Setup GPIO for output
  pinMode(23, OUTPUT); // Red LED 
  pinMode(22, OUTPUT); // Yellow LED
  pinMode(21, OUTPUT); // Blue LED
}

void loop() {
  // put your main code here, to run repeatedly:
  delay (250); // Wait but do nothing special
  Serial.println(" I am ESP32!");
  digitalWrite(23, HIGH);
  digitalWrite(22, LOW);
  digitalWrite(21, HIGH);

  delay (250) ; // wait but do nothing special
  digitalWrite(23, LOW);
  digitalWrite(22, HIGH);
  digitalWrite(21, LOW);
}