void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(16, OUTPUT);
  pinMode(17, OUTPUT);
  pinMode(18, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(4,HIGH);
  digitalWrite(5,LOW);
  digitalWrite(16,LOW);
  digitalWrite(17,LOW);
  digitalWrite(18,LOW);
  delay(100); // this speeds up the simulation
  digitalWrite(4,LOW);
  digitalWrite(5,HIGH);
  digitalWrite(16,LOW);
  digitalWrite(17,LOW);
  digitalWrite(18,LOW);
  delay(100);
  digitalWrite(4,LOW);
  digitalWrite(5,LOW);
  digitalWrite(16,HIGH);
  digitalWrite(17,LOW);
  digitalWrite(18,LOW);
  delay(100);
  digitalWrite(4,LOW);
  digitalWrite(5,LOW);
  digitalWrite(16,LOW);
  digitalWrite(17,HIGH);
  digitalWrite(18,LOW);
  delay(100);
  digitalWrite(4,LOW);
  digitalWrite(5,LOW);
  digitalWrite(16,LOW);
  digitalWrite(17,LOW);
  digitalWrite(18,HIGH);
}