这是单片机开发的一个程序，我当时做的是一个电子计时器，写了很久的，虽然现在看来还是挺简单，但是对于那些初学者还是很有用处的-This is a single-chip development process, I was to do an electronic timer and write for a long time, although now it seems pretty simple, but for those beginners or useful