// Traffic Light with 3 LEDs and Push Button
// Red LED connected to pin 13
// Yellow LED connected to pin 12
// Green LED connected to pin 11
// Push button connected to pin 7

int button = 7;
int state = HIGH;
int previous = LOW;
int redPin = 13;
int yellowPin = 12;
int greenPin = 11;

void setup()
{
  pinMode(redPin, OUTPUT); // Red LED
  pinMode(yellowPin, OUTPUT); // Yellow LED
  pinMode(greenPin, OUTPUT); // Green LED
  pinMode(button, INPUT); // Push button
}

void loop()
{
  state = digitalRead(button);
  if (state == HIGH && previous == LOW) {
    digitalWrite(redPin, LOW); // Red light off
    digitalWrite(yellowPin, HIGH); // Yellow light on
    delay(2000); // Wait for 2 seconds
    digitalWrite(yellowPin, LOW); // Yellow light off
    digitalWrite(greenPin, HIGH); // Green light on
    delay(5000); // Wait for 5 seconds
    digitalWrite(greenPin, LOW); // Green light off
    digitalWrite(yellowPin, HIGH); // Yellow light on
    delay(2000); // Wait for 2 seconds
    digitalWrite(yellowPin, LOW); // Yellow light off
    digitalWrite(redPin, HIGH); // Red light on
  }
  previous = state;
}//