接上个源码 delay()延时函数消耗的时间太长了，其它任务根本没有机会执行，我们该怎么改善？本节教大家利用累计主循环次数的方法来解决这个问题。这一节要教会大家两个知识点：

第一点：利用累计主循环次数的方法实现时间延时

第二点：switch核心语句之初体验。 所有的实战项目都是基于switch语句实现多任务并行处理。

实现功能：让一个LED闪烁。-Connected to a source delay () function consumes delay too long, there is no opportunity to perform other tasks, how can we improve? This section will teach you the use of the cumulative number of cycles of the main ways to solve this problem. In this section you two knowledge points to the church:

First point: the use of the cumulative number of methods to achieve the main loop time delay

The second point: switch statement at the beginning of the core experience. All projects are based on the actual switch statement to achieve parallel processing of multiple tasks.

Function: make an LED blink.