#define GREENLED_PIN 13
#define YELLOWLED_PIN 12
#define REDLED_PIN 11

#define BUTTON_PIN 10
#define ONE_SECOND 1000

int currentButtonValue = 0;
int previousButtonValue = 0;

void setup() {
  pinMode(GREENLED_PIN, OUTPUT);
  pinMode(YELLOWLED_PIN, OUTPUT);
  pinMode(REDLED_PIN, OUTPUT);  
  
  pinMode(BUTTON_PIN, INPUT);

  digitalWrite(GREENLED_PIN, HIGH);
}

void trafficLight() {
  digitalWrite(GREENLED_PIN, LOW);
  digitalWrite(YELLOWLED_PIN, HIGH);

  delay(ONE_SECOND);

  digitalWrite(YELLOWLED_PIN, LOW);
  digitalWrite(REDLED_PIN, HIGH);

  delay(ONE_SECOND * 3);

  digitalWrite(REDLED_PIN, LOW);
  digitalWrite(GREENLED_PIN, HIGH);  
}

void loop() {
  currentButtonValue = digitalRead(BUTTON_PIN);

  if (currentButtonValue == 1 && currentButtonValue != previousButtonValue)
    trafficLight();

  previousButtonValue = currentButtonValue;
}