学习设计一个复杂嵌入式应用程序的方法，编写一个综合的嵌入式应用程序，包括操作系统的任务调用，液晶屏的绘图函数的调用等-study design a complex embedded application procedure for the preparation of an integrated embedded applications, including the task of calling operating system, the LCD screen mapping function call, etc.