每次按下 K1 时递增点亮一只LED，全亮时再次按下则再次循环开始，

K2按下后点亮上面4 只LED，K3 按下后点亮下面4 只LED，K4 按下后关闭所有LED-Each press K1 increments lit a LED full brightness when pressed again, the cycle begins again after 4 LED lit above press K2, K3 Press lit following four LED K4 Press Close all LED