sunside

// simple LED traffic light Arduino sketch
// http://www.youtube.com/watch?v=Y67EzJB7QYU

const int pinR = 13;
const int pinY = 12;
const int pinG = 11;

const int durationMs = 4000;

typedef enum EState {
  RED = 0,
  YELLOW = 1,
  GREEN = 2,
  REDYELLOW = 3
} State;

State light = RED;

void setup()
{
    pinMode(pinR, OUTPUT);
    pinMode(pinY, OUTPUT);
    pinMode(pinG, OUTPUT);

    // blink yellow
    for(int i=0; i<5; ++i)
    {
        digitalWrite(pinY, HIGH);
        delay(1000);
        digitalWrite(pinY, LOW);
        delay(1000);
    }

    // switch to red and wait
    digitalWrite(pinR, HIGH);
    delay(2000);
}

void loop()
{
    switch(light)
    {
        case RED:
            digitalWrite(pinR, HIGH);
            digitalWrite(pinY, LOW);
            light = REDYELLOW;
            break;

        case REDYELLOW:
            digitalWrite(pinR, HIGH);
            digitalWrite(pinY, HIGH);
            digitalWrite(pinG, LOW);
            light = GREEN;
            break;

        case GREEN:
            digitalWrite(pinR, LOW);
            digitalWrite(pinY, LOW);
            digitalWrite(pinG, HIGH);
            light = YELLOW;
            break;

        case YELLOW:
            digitalWrite(pinY, HIGH);
            digitalWrite(pinG, LOW);
            light = RED;
            break;
    }

    delay(durationMs);
}