跑马灯试验，先是奇数灯亮，然后偶数灯亮，然后从中间到两边亮，在两边到中间。（用定时器2实现延时）-Marquee pilot, first odd-numbered lights, and then even-numbered lights, and then from the middle to both sides of light in the middle on both sides. (Used to achieve delay timer 2)