class LED {
  public:
    LED(byte pin, uint16_t prd) {
      _pin = pin;
      _prd = prd;
      pinMode(_pin, OUTPUT);
    }
    void blink() {
      if (millis() - _tmr >= _prd) {
        _tmr = millis();
        _flag = !_flag;
        digitalWrite(_pin, _flag);
      }
    }
  private:
    byte _pin;
    uint32_t _tmr;
    uint16_t _prd;
    bool _flag;
};
LED led1(13, 500);
LED led2(2, 1000);
void setup() {
}
void loop() {
  led1.blink();
  led2.blink();
}