实现两个单片机之间的串口通信，一个单片机定时用作电子时钟，将时间通过串口送给另一个单片机，收到后从数码管显示时间，且可用按键调整时间-Serial communication between two microcontrollers, a single-chip timing as an electronic clock, the time to give another microcontroller through the serial port, after receiving the