// red
// yellow
// green

int traffic_light_1[3] = {1, 2, 3};
int traffic_light_2[3] = {4, 5, 6};
int move_time = 4000;
int yellow_time = 500;

void setup() {
  // set the outputs
  for(int i=0; i <= 3; i++){
    pinMode(traffic_light_1[i], OUTPUT);
    pinMode(traffic_light_2[i], OUTPUT);
  }

}

void loop() {
  // light 1 is red at first
  digitalWrite(traffic_light_1[0], HIGH);
  digitalWrite(traffic_light_1[1], LOW);
  digitalWrite(traffic_light_1[2], LOW);

  // light 2 is green at first
  digitalWrite(traffic_light_2[0], LOW);
  digitalWrite(traffic_light_2[1], LOW);
  digitalWrite(traffic_light_2[2], HIGH);

  delay(move_time);

  // light 2 became yellow
  digitalWrite(traffic_light_2[0], LOW);
  digitalWrite(traffic_light_2[1], HIGH);
  digitalWrite(traffic_light_2[2], LOW);


  delay(yellow_time);

  // light 1 became green
  digitalWrite(traffic_light_1[0], LOW);
  digitalWrite(traffic_light_1[1], LOW);
  digitalWrite(traffic_light_1[2], HIGH);


  // light 2 became red
  digitalWrite(traffic_light_2[0], HIGH);
  digitalWrite(traffic_light_2[1], LOW);
  digitalWrite(traffic_light_2[2], LOW);

  delay(move_time);


  // light 1 became yellow
  digitalWrite(traffic_light_1[0], LOW);
  digitalWrite(traffic_light_1[1], HIGH);
  digitalWrite(traffic_light_1[2], LOW);


  delay(yellow_time);

}
// Amir Aref