void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  Serial.println("This is a 4 way traffic light signal.");
  Serial.println("Follow the rules for your safety!");
  const int red_left = 23;
  const int yellow_left = 22;
  const int green_left = 21;

  const int red_up = 0;
  const int yellow_up = 2;
  const int green_up = 15;

  const int red_right = 19;
  const int yellow_right = 18;
  const int green_right = 5;

  const int red_down = 17;
  const int yellow_down = 16;
  const int green_down = 4;

  const int go = 4000;
  const int wait = 2000;


  pinMode(red_left, OUTPUT);
  pinMode(yellow_left, OUTPUT);
  pinMode(green_left, OUTPUT);
  pinMode(red_up, OUTPUT);
  pinMode(yellow_up, OUTPUT);
  pinMode(green_up, OUTPUT);
  pinMode(red_right, OUTPUT);
  pinMode(yellow_right, OUTPUT);
  pinMode(green_right, OUTPUT);
  pinMode(red_down, OUTPUT);
  pinMode(yellow_down, OUTPUT);
  pinMode(green_down, OUTPUT);
}

void loop() {

  const int red_left = 23;
  const int yellow_left = 22;
  const int green_left = 21;

  const int red_up = 0;
  const int yellow_up = 2;
  const int green_up = 15;

  const int red_right = 19;
  const int yellow_right = 18;
  const int green_right = 5;

  const int red_down = 17;
  const int yellow_down = 16;
  const int green_down = 4;

  const int go = 4000;
  const int wait = 2000;

  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation

  // green left
  digitalWrite(red_left, LOW);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, HIGH);
  digitalWrite(red_up, HIGH);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, HIGH);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, HIGH);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, LOW);
  delay(go);
  // wait yellow left,up
  digitalWrite(red_left, LOW);
  digitalWrite(yellow_left, HIGH);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, LOW);
  digitalWrite(yellow_up, HIGH);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, HIGH);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, HIGH);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, LOW);
  delay(wait);

  // green up
  digitalWrite(red_left, HIGH);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, LOW);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, HIGH);
  digitalWrite(red_right, HIGH);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, HIGH);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, LOW);
  delay(go);
  // wait yellow up,right
  digitalWrite(red_left, HIGH);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, LOW);
  digitalWrite(yellow_up, HIGH);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, LOW);
  digitalWrite(yellow_right, HIGH);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, HIGH);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, LOW);
  delay(wait);

  // green right
  digitalWrite(red_left, HIGH);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, HIGH);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, LOW);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, HIGH);
  digitalWrite(red_down, HIGH);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, LOW);
  delay(go);
  // wait yellow right,down
  digitalWrite(red_left, HIGH);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, HIGH);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, LOW);
  digitalWrite(yellow_right, HIGH);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, LOW);
  digitalWrite(yellow_down, HIGH);
  digitalWrite(green_down, LOW);
  delay(wait);

  // green down
  digitalWrite(red_left, HIGH);
  digitalWrite(yellow_left, LOW);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, HIGH);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, HIGH);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, LOW);
  digitalWrite(yellow_down, LOW);
  digitalWrite(green_down, HIGH);
  delay(go);
  // wait yellow down,left
  digitalWrite(red_left, LOW);
  digitalWrite(yellow_left, HIGH);
  digitalWrite(green_left, LOW);
  digitalWrite(red_up, HIGH);
  digitalWrite(yellow_up, LOW);
  digitalWrite(green_up, LOW);
  digitalWrite(red_right, HIGH);
  digitalWrite(yellow_right, LOW);
  digitalWrite(green_right, LOW);
  digitalWrite(red_down, LOW);
  digitalWrite(yellow_down, HIGH);
  digitalWrite(green_down, LOW);
  delay(wait);




}