// NORTH
int N_R = 25;
int N_Y = 26;
int N_G = 27;

// EAST
int E_R = 5;
int E_Y = 4;
int E_G = 2;

// SOUTH
int S_R = 12;
int S_Y = 13;
int S_G = 14;

// WEST
int W_R = 15;
int W_Y = 16;
int W_G = 17;

void setup() {
  pinMode(N_R, OUTPUT); pinMode(N_Y, OUTPUT); pinMode(N_G, OUTPUT);
  pinMode(E_R, OUTPUT); pinMode(E_Y, OUTPUT); pinMode(E_G, OUTPUT);
  pinMode(S_R, OUTPUT); pinMode(S_Y, OUTPUT); pinMode(S_G, OUTPUT);
  pinMode(W_R, OUTPUT); pinMode(W_Y, OUTPUT); pinMode(W_G, OUTPUT);
}

void loop() {
  // NORTH
  allRed();
  digitalWrite(N_G, HIGH);
  digitalWrite(N_R, LOW);
  delay(5000);
  yellow(N_Y, N_G, N_R);

  // EAST
  allRed();
  digitalWrite(E_G, HIGH);
  digitalWrite(E_R, LOW);
  delay(5000);
  yellow(E_Y, E_G, E_R);

  // SOUTH
  allRed();
  digitalWrite(S_G, HIGH);
  digitalWrite(S_R, LOW);
  delay(5000);
  yellow(S_Y, S_G, S_R);

  // WEST
  allRed();
  digitalWrite(W_G, HIGH);
  digitalWrite(W_R, LOW);
  delay(5000);
  yellow(W_Y, W_G, W_R);
}

void yellow(int Y, int G, int R) {
  digitalWrite(G, LOW);
  digitalWrite(Y, HIGH);
  delay(2000);
  digitalWrite(Y, LOW);
  digitalWrite(R, HIGH);
}

void allRed() {
  digitalWrite(N_R, HIGH); digitalWrite(N_Y, LOW); digitalWrite(N_G, LOW);
  digitalWrite(E_R, HIGH); digitalWrite(E_Y, LOW); digitalWrite(E_G, LOW);
  digitalWrite(S_R, HIGH); digitalWrite(S_Y, LOW); digitalWrite(S_G, LOW);
  digitalWrite(W_R, HIGH); digitalWrite(W_Y, LOW); digitalWrite(W_G, LOW);
}