const int BTN = D2;

const uint8_t LED_PINS[] = { PIN_LED_R, PIN_LED_G, PIN_LED_B };
const int LED_COUNT = 3;

bool ledOn = false;

void ledApply() {
  for (int i = 0; i < LED_COUNT; i++) {
    digitalWrite(LED_PINS[i], ledOn ? LOW : HIGH);
  }
  Serial.println(ledOn ? F("LED ON") : F("LED OFF"));
}

void setup() {
  for (int i = 0; i < LED_COUNT; i++) {
    pinMode(LED_PINS[i], OUTPUT);
    digitalWrite(LED_PINS[i], HIGH);
  }
  pinMode(BTN, INPUT_PULLUP);
  Serial.begin(115200);
}

void loop() {
  if (Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    cmd.trim();
    if (cmd == "on") {
      ledOn = true;
      ledApply();
    } else if (cmd == "off") {
      ledOn = false;
      ledApply();
    }
  }

  if (digitalRead(BTN) == LOW) {
    ledOn = !ledOn;
    ledApply();
    delay(300);
  }
}