/*
  RGB LED with button demo
  LED is common cathode!
*/

const int BTN_PIN = 5;
const int RED_LED_PIN = 4;
const int GRN_LED_PIN = 3;
const int BLU_LED_PIN = 2;
const char* MODE_COLORS[] = {
  "Red", "Green", "Blue"
};

int mode = 0;
int oldMode = -1;
int oldBtnVal = HIGH;  // pullup idles HIGH

void allOff() {
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(GRN_LED_PIN, LOW);
  digitalWrite(BLU_LED_PIN, LOW);
}

void checkButton()  {
  int btnVal = digitalRead(BTN_PIN);
  if (btnVal != oldBtnVal)  {
    oldBtnVal = btnVal;
    if (btnVal == LOW) {
      mode++;
      if (mode == 3) mode = 0;
    }
    delay(20);
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(BTN_PIN, INPUT_PULLUP);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GRN_LED_PIN, OUTPUT);
  pinMode(BLU_LED_PIN, OUTPUT);
  Serial.println("Push the button!\n");
}

void loop() {
  checkButton();
  if (mode != oldMode)  {
    oldMode = mode;
    allOff();
    Serial.println(MODE_COLORS[mode]);
    if (mode == 0)  {
      digitalWrite(RED_LED_PIN, HIGH);
    } else if (mode == 1) {
      digitalWrite(GRN_LED_PIN, HIGH);
    } else if (mode == 2) {
      digitalWrite(BLU_LED_PIN, HIGH);
    }
  }
}