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 mi