系统平时处于循环接收检测状态，当有按键动作后发送数据 ，对方收到数据后LED闪烁， 任何一方可以发数据也可以收数据。 1． 当检测到按键动作后发送数据，自身LED闪烁 2． 当收到数据后LED闪烁 -Usually in the loop receiver detect state data, send keystrokes LED flashes after receipt of this data, either party can send data can also