51单片机实现串口接受和发送，Proteus仿真

在“2.1 键盘和LED 数码管显示设计”基础上，增加如下内容：

1、SCI 串行口、TTL-232 电平转换部分电路原理图；

2、相应程序流程图；

3、编程调试，在2.1 基础上，实现串口接收、发送功能，具体如下：

（1）按下某键，通过串口送出按下键的键号（重复4 字节）并在虚拟终端上显示；

（2）在虚拟终端上输入4 位要显示的数值，串行口接收后，在数码管上显示，数

值输入数据格式为‘s’、‘0~9’、‘0~9’、‘0~9’、‘0~9’、‘e’。-In the　2.1 LED keyboard and digital tube display design on the basis of , add the following content:

Part of the circuit diagram 1, SCI serial port, TTL-232 level conversion

2, the corresponding program flow chart

3, programming and debugging, based on the 2.1, realize the serial port to receive, send function, as follows:

(1) press of a key, through the serial port to send key press number keys (repeat 4 bytes) and displayed on a virtual terminal

(2) 4 bits of input to the displayed value on a virtual terminal, serial port after receiving, in the digital tube display, number

Value of the input data format is　s ,　0~9 ,　0~9 ,　0~9 ,　0~9 ,　e .