按键中断，实现不同的时钟配置及转换，并以LED灯的闪烁进行体现，并通过串口发送按键按下信息时钟配置以及LED灯的闪烁状态，尽可能多的实现不同时钟的切换。-Key interrupt achieve different clock configuration and conversion, and blinking LED lights were reflected, and press the clock configuration information and blinking LED li