Adafruit7TrafficLight.ino

/*
 * Traffic signal RGB LED from Adafruit Arduino lesson suggestion
 */

int redLEDPin = 11;
int greenLEDPin = 10;
int blueLEDPin = 9;

int buttonPin = 7;
boolean lastButtonState;

// Technically this "yellow" is orange which shows up nicer on the LED.
//                       { off   red   yellow  green }
byte redLEDStates[4]   = { 0x00, 0xFF, 0xFF,   0x00 };
byte greenLEDStates[4] = { 0x00, 0x00, 0x66,   0xFF };
byte blueLEDStates[4]  = { 0x00, 0x00, 0x00,   0x00 };
int currentState = 0;

void setup() {
  pinMode(redLEDPin, OUTPUT);
  pinMode(greenLEDPin, OUTPUT);
  pinMode(blueLEDPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);
  lastButtonState = digitalRead(buttonPin);
}

void loop() {
  boolean newButtonState = digitalRead(buttonPin);
  if (newButtonState == HIGH && lastButtonState == LOW) {
    currentState++;
    if (currentState > 3) currentState = 0;
    updateTrafficLEDs();
  }
  lastButtonState = newButtonState;
  
  delay(10); // debounce
}

void updateTrafficLEDs() {
  analogWrite(redLEDPin, redLEDStates[currentState]);
  analogWrite(greenLEDPin, greenLEDStates[currentState]);
  analogWrite(blueLEDPin, blueLEDStates[currentState]);
}