说明：  说明，实用的键盘状态机处理程序，利用状态机去拌动，兼有部分键单触发和部分键连发功能。连发时间间隔和消抖时间方便设定。是我工程中常用的部分。利用状态机条理清晰，处理效率高。
(Note, practical keyboard state machine handling procedures, using the state machine to mix action, both part of the keys and some keys repeating one-shot function. Repeating time interval, and shaking at times convenient to set the consumer. I used part of the project. Clarity using the state machine to deal with high efficiency.)