跑马灯：用到键盘(修改闪烁速度等)，定时器，中断。通过LED指示灯实现从左到右，从右到左，从两边到中间，从中间到两边，所有的LED同时快速闪烁与慢闪-Marquee: to use the keyboard (to modify the flashing speed, etc.), the timer interrupt. LED indicator from left to right, right to left, from both sides to the middle, from middle to both sides, all of the LED also flashes quickly and slow flash