进行两个stm32之间的有线通信，通过按键发送信息到另一个开发板，发送信息绿灯灯亮五次，接收信息红灯灯亮五次，并在LCD上显示发送的字符。只能发送特定字符(For two STM32 between the wire communication, through the button to send information to another development board, send information, green light five times, receive informa