串口通信_选择串口翻译怎么操作-优快云博客

本文详细介绍了51单片机的串口通信原理及实现过程，包括单工、半双工和全双工等通信方式，并提供了一个具体的串口通信实例代码。

串行通信的传输方式：
单工，半双工，全双工。
51单片机的串口属于全双工通信
异步通信：使用各自的时钟
同步通信：使用相同的时钟

采用8N1模式（8个数据位，n0个校验位，一个停止位，一个起始位，其中起始位是通信标准，必须要有）

使用串口定时器1不能被使用
这里写图片描述

其中俩个SBUF的名字相同，地址不同，物理上是独立的。

波特率 = (2^SMOD * fosc)/(32 * 12*(256-x))
SMOD默认为0

写串口的工作

1.设置串口工作方式
2.打开ENA
3.设置发送接收波特率
1）设置定时器1工作方式为8位自动重装方式，即方式2
2）填初值（TH1）
3）打开定时器

<code class="hljs cpp has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <reg52.h></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include "./delay/delay.h"</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// #include <stdio.h></span>

<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//初始化</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> uart_init()
{
    SCON = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0x50</span>;
    TMOD |= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0x20</span>;
    TH1 = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0xfd</span>;
    TR1 = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//发送字节</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> uart_send_byte(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">unsigned</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">char</span> byte)
{
    SBUF = byte;
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span>(!TI);
    TI = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//发送字符串</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> uart_send_string(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">unsigned</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">char</span> *s)
{
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span>(*s != <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'\0'</span>)
    {
         uart_send_byte(*s);
    s++;
    }
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//调用主函数</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> main()
{
     <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">unsigned</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">char</span> s[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>];
     <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">unsigned</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">char</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;

     uart_init();
     uart_send_string(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"please input the char:\n"</span>);
         <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)
     {
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(RI)
            {

                 <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(i >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>)
                 {
                      <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
                                 }
                 <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(SBUF == <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">' '</span>)
                 {
                       <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
                                 }
                         s[i] = SBUF;
                  i++;
                  RI = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
                      }

                    delay_ms(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>);
        }
     uart_send_string(s);
     uart_send_string(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"\t\n"</span>);
}</code>