单片机与PC机串口通讯资料_proteus_单片机 _其他

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0">用<span class="_ _0"></span>MFC<span class="_ _0"></span>实现串<span class="_ _1"></span>口编程</div><div class="t m0 x2 h3 y2 ff1 fs1 fc1 sc1 ls0 ws0">龚建伟评论：本文既写了在<span class="_ _2"></span>Windows<span class="_ _2"></span>中怎样用<span class="_ _2"></span>VC<span class="_ _2"></span>控件<span class="_ _2"></span>MSComm，又说明了<span class="_ _3"></span>API</div><div class="t m0 x3 h3 y3 ff1 fs1 fc1 sc1 ls0 ws0">技术编程方法，在写用<span class="_ _4"></span>MSComm<span class="_ _4"></span>控件时，数据类型的转换说得不是太明白，初次</div><div class="t m0 x3 h3 y4 ff1 fs1 fc1 sc1 ls0 ws0">涉猎串口编程的朋友恐怕看了还是编不出来；直接从底层编写的部分值得一</div><div class="t m0 x3 h3 y5 ff1 fs1 fc1 sc1 ls0 ws0">读，说得较为详细，但你得先从<span class="_ _4"></span>VC<span class="_ _4"></span>教本上看一看什么是线程。</div><div class="t m0 x3 h3 y6 ff1 fs1 fc1 sc2 ls0 ws0">一．串行通信<span class="_ _1"></span>的基本原理</div><div class="t m0 x3 h3 y7 ff1 fs1 fc1 sc2 ls0 ws0">二．串口信号<span class="_ _1"></span>线的接法</div><div class="t m0 x3 h3 y8 ff1 fs1 fc1 sc2 ls0 ws0">三．16<span class="_ _4"></span>位串<span class="_ _1"></span>口应用程序的<span class="_ _1"></span>简单回顾</div><div class="t m0 x3 h3 y9 ff1 fs1 fc1 sc2 ls0 ws0">四．在<span class="_ _4"></span>MF<span class="_ _1"></span>C<span class="_ _4"></span>下的<span class="_ _4"></span>32<span class="_ _4"></span>位串口应<span class="_ _1"></span>用程序</div><div class="t m0 x3 h3 ya ff1 fs1 fc1 sc2 ls0 ws0">㈠<span class="_ _5"></span>使用<span class="_ _4"></span>Acti<span class="_ _1"></span>veX<span class="_ _4"></span>控件</div><div class="t m0 x3 h3 yb ff1 fs1 fc1 sc2 ls0 ws0">㈡<span class="_ _5"></span>使用<span class="_ _4"></span>32<span class="_ _4"></span>位<span class="_ _1"></span>的<span class="_ _4"></span>API<span class="_ _5"></span>通信函数</div><div class="t m0 x2 h3 yc ff1 fs1 fc1 sc1 ls0 ws0">本文详细介绍了串行通信的基本原理，以及在<span class="_ _3"></span>Windows<span class="_ _5"></span>NT、Win98<span class="_ _3"></span>环境下用</div><div class="t m0 x3 h3 yd ff1 fs1 fc1 sc1 ls0 ws0">MFC<span class="_ _4"></span>实现串口（COM）通信的方法：使用<span class="_ _4"></span>ActiveX<span class="_ _4"></span>控件或<span class="_ _4"></span>Win<span class="_ _5"></span>API.并给出用</div><div class="t m0 x3 h3 ye ff1 fs1 fc1 sc1 ls0 ws0">Visual<span class="_ _5"></span>C++6.0<span class="_ _4"></span>编写的相应<span class="_ _4"></span>MFC32<span class="_ _4"></span>位应用程序。关键词：串行通信、VC++6.0、</div><div class="t m0 x3 h3 yf ff1 fs1 fc1 sc1 ls0 ws0">ActiveX<span class="_ _4"></span>控件、Win<span class="_ _5"></span>API、MFC32<span class="_ _4"></span>位应用程序、事件驱动、非阻塞通信、多线程.</div><div class="t m0 x4 h3 y10 ff1 fs1 fc1 sc1 ls0 ws0">在<span class="_ _4"></span>Windows<span class="_ _4"></span>应用程序的开发中，我们常常需要面临与外围数据源设备通信</div><div class="t m0 x3 h3 y11 ff1 fs1 fc1 sc1 ls0 ws0">的问题。计算机和单片机（如<span class="_ _4"></span>MCS-51）都具有串行通信口，可以设计相应的串</div><div class="t m0 x3 h3 y12 ff1 fs1 fc1 sc1 ls0 ws0">口通信程序，完成二者之间的数据通信任务。</div><div class="t m0 x4 h3 y13 ff1 fs1 fc1 sc1 ls0 ws0">实际工作中利用串口完成通信任务的时候非常之多。已有一些文章介绍串</div><div class="t m0 x3 h3 y14 ff1 fs1 fc1 sc1 ls0 ws0">口编程的文章在计算机杂志上发表。但总的感觉说来不太全面，特别是介绍<span class="_ _4"></span>32</div><div class="t m0 x3 h3 y15 ff1 fs1 fc1 sc1 ls0 ws0">位下编<span class="_ _5"></span>程的更少，且很不详细。笔者在实际工作中积累了较多经验,结合硬</div><div class="t m0 x3 h3 y16 ff1 fs1 fc1 sc1 ls0 ws0">件、软件，重点提及比较新的技术，及需要注意的要点作一番探讨。希望对各</div><div class="t m0 x3 h3 y17 ff1 fs1 fc1 sc1 ls0 ws0">位需要编写串口通<span class="_ _5"></span>信程序的朋友有一些帮助。</div><div class="t m0 x3 h3 y18 ff1 fs1 fc1 sc2 ls0 ws0">一．串行通信<span class="_ _1"></span>的基本原理</div><div class="t m0 x2 h3 y19 ff1 fs1 fc1 sc1 ls0 ws0">串行端口的本质功能是作为<span class="_ _3"></span>CPU<span class="_ _3"></span>和串行设备间的编码转换器。当数据从<span class="_ _5"></span>CPU</div><div class="t m0 x3 h3 y1a ff1 fs1 fc1 sc1 ls0 ws0">经过串行端口发送出去时，字节数据转换为串行的位。在接收数据时，串行的</div><div class="t m0 x3 h3 y1b ff1 fs1 fc1 sc1 ls0 ws0">位被转换为字节数据。</div><div class="t m0 x2 h3 y1c ff1 fs1 fc1 sc1 ls0 ws0">在<span class="_ _3"></span>Windows<span class="_ _3"></span>环境（Windows<span class="_ _5"></span>NT、Win98、Windows2000）下，串口是系统资源</div><div class="t m0 x3 h3 y1d ff1 fs1 fc1 sc1 ls0 ws0">的一部分。</div><div class="t m0 x2 h3 y1e ff1 fs1 fc1 sc1 ls0 ws0">应用程序要使用串口进行通信，必须在使用之前向操作系统提出资源申请</div><div class="t m0 x3 h3 y1f ff1 fs1 fc1 sc1 ls0 ws0">要求（打开串口），通信完成后必须释放资源（关闭串口）。</div><div class="t m0 x3 h3 y20 ff1 fs1 fc1 sc2 ls0 ws0">二．串口信号<span class="_ _1"></span>线的接法</div><div class="t m0 x2 h3 y21 ff1 fs1 fc1 sc1 ls0 ws0">一个完整的<span class="_ _4"></span>RS-232C<span class="_ _6"></span>接口有<span class="_ _4"></span>22<span class="_ _6"></span>根线，采用标准的<span class="_ _4"></span>25<span class="_ _6"></span>芯插头座（或者<span class="_ _6"></span>9<span class="_ _4"></span>芯插</div><div class="t m0 x3 h3 y22 ff1 fs1 fc1 sc1 ls0 ws0">头座）。25<span class="_ _4"></span>芯和<span class="_ _4"></span>9<span class="_ _4"></span>芯的主要信号线相同。以下的介绍是以<span class="_ _4"></span>25<span class="_ _4"></span>芯的<span class="_ _4"></span>RS-232C<span class="_ _4"></span>为</div><div class="t m0 x3 h3 y23 ff1 fs1 fc1 sc1 ls0 ws0">例。</div><div class="t m0 x3 h3 y24 ff1 fs1 fc1 sc1 ls0 ws0">①主要信号线定义：</div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611926,0.000000,0.000000,1.611926,0.000000,0.000000]}'></div></div> </body> </html>

<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/bg2.jpg"><div class="t m0 x3 h3 y25 ff1 fs1 fc1 sc1 ls0 ws0">2<span class="_ _4"></span>脚：发送数据<span class="_ _6"></span>TXD；<span class="_ _5"></span>3<span class="_ _6"></span>脚：接收数据<span class="_ _4"></span>RXD；<span class="_ _5"></span>4<span class="_ _6"></span>脚：请求发送<span class="_ _6"></span>RTS；<span class="_ _5"></span>5<span class="_ _6"></span>脚：清除</div><div class="t m0 x3 h3 y26 ff1 fs1 fc1 sc1 ls0 ws0">发送<span class="_ _3"></span>CTS；<span class="_ _5"></span>6<span class="_ _6"></span>脚：数据设备就绪<span class="_ _3"></span>DSR；20<span class="_ _3"></span>脚：数据终端就绪<span class="_ _3"></span>DTR；<span class="_ _5"></span>8<span class="_ _3"></span>脚：数据载</div><div class="t m0 x3 h3 y27 ff1 fs1 fc1 sc1 ls0 ws0">波检测<span class="_ _4"></span>DCD；1<span class="_ _4"></span>脚：保护地；<span class="_ _5"></span>7<span class="_ _4"></span>脚：信号地。</div><div class="t m0 x3 h3 y28 ff1 fs1 fc1 sc1 ls0 ws0">②电气特性：</div><div class="t m0 x2 h3 y29 ff1 fs1 fc1 sc1 ls0 ws0">数据传输速率最大可到<span class="_ _4"></span>20K<span class="_ _5"></span>bps,最大距离仅<span class="_ _4"></span>15m.</div><div class="t m0 x2 h3 y2a ff1 fs1 fc1 sc1 ls0 ws0">注：看了微软的<span class="_ _4"></span>MSDN<span class="_ _5"></span>6.0，其<span class="_ _4"></span>Windows<span class="_ _5"></span>API<span class="_ _4"></span>中关于串行通讯设备（不一定</div><div class="t m0 x3 h3 y2b ff1 fs1 fc1 sc1 ls0 ws0">都是串口<span class="_ _4"></span>RS-232C<span class="_ _4"></span>或<span class="_ _4"></span>RS-422<span class="_ _4"></span>或<span class="_ _4"></span>RS-449）速率的设置，最大可支持到</div><div class="t m0 x3 h3 y2c ff1 fs1 fc1 sc1 ls0 ws0">RS_256000，即<span class="_ _4"></span>256K<span class="_ _5"></span>bps!<span class="_ _5"></span>也不知道到底是什么串行通讯设备？但不管怎样，</div><div class="t m0 x3 h3 y2d ff1 fs1 fc1 sc1 ls0 ws0">一般主机和单片机的串口通讯大多都在<span class="_ _4"></span>9600<span class="_ _5"></span>bps,可以满足通讯需求。</div><div class="t m0 x3 h3 y2e ff1 fs1 fc1 sc1 ls0 ws0">③接口的典型应用：</div><div class="t m0 x2 h3 y2f ff1 fs1 fc1 sc1 ls0 ws0">大多数计算机应用系统与智能单元之间只需使用<span class="_ _6"></span>3<span class="_ _6"></span>到<span class="_ _6"></span>5<span class="_ _6"></span>根信号线即可工作。</div><div class="t m0 x3 h3 y30 ff1 fs1 fc1 sc1 ls0 ws0">这时，除了<span class="_ _4"></span>TXD、RXD<span class="_ _4"></span>以外，还需使用<span class="_ _4"></span>RTS、CTS、DCD、DTR、DSR<span class="_ _4"></span>等信号线。</div><div class="t m0 x3 h3 y31 ff1 fs1 fc1 sc1 ls0 ws0">（当然，在程序中也需要对相应的信号线进行设置。）</div><div class="t m0 x4 h3 y32 ff1 fs1 fc1 sc1 ls0 ws0">以上接法，在设计程序时，直接进行数据的接收和发送就可以了，不需要</div><div class="t m0 x3 h3 y33 ff1 fs1 fc1 sc1 ls0 ws0">对信号线的状态进行判断或设置。（如果应用的场合需要使用握手信号等，需</div><div class="t m0 x3 h3 y34 ff1 fs1 fc1 sc1 ls0 ws0">要对相应的信号线的状态进行监测或设置。）</div><div class="t m0 x3 h3 y35 ff1 fs1 fc1 sc2 ls0 ws0">三．16<span class="_ _4"></span>位串<span class="_ _1"></span>口应用程序的<span class="_ _1"></span>简单回顾</div><div class="t m0 x4 h3 y36 ff1 fs1 fc1 sc1 ls0 ws0">16<span class="_ _4"></span>位串口应用程序中，使用的<span class="_ _4"></span>16<span class="_ _4"></span>位的<span class="_ _4"></span>Windows<span class="_ _5"></span>API<span class="_ _4"></span>通信函数:</div><div class="t m0 x3 h3 y37 ff1 fs1 fc1 sc1 ls0 ws0">①<span class="_ _5"></span>OpenComm()<span class="_ _5"></span>打开串口资源，并指定输入、输出缓冲区的大小（字节）；</div><div class="t m0 x5 h3 y38 ff1 fs1 fc1 sc1 ls0 ws0">CloseComm()<span class="_ _5"></span>关闭串口;</div><div class="t m0 x6 h3 y39 ff1 fs1 fc1 sc1 ls0 ws0">例：int<span class="_ _5"></span>idComDev;</div><div class="t m0 x4 h3 y3a ff1 fs1 fc1 sc1 ls0 ws0">idComDev<span class="_ _5"></span>=<span class="_ _5"></span>OpenComm("COM1",<span class="_ _5"></span>1024,<span class="_ _5"></span>128);</div><div class="t m0 x7 h3 y3b ff1 fs1 fc1 sc1 ls0 ws0">CloseComm(idComDev);</div><div class="t m0 x3 h3 y3c ff1 fs1 fc1 sc1 ls0 ws0">②<span class="_ _5"></span>BuildCommDCB()<span class="_ _5"></span>、setCommState()填写设备控制块<span class="_ _4"></span>DCB，然后对已打开的</div><div class="t m0 x3 h3 y3d ff1 fs1 fc1 sc1 ls0 ws0">串口进行参数配置;</div><div class="t m0 x3 h3 y3e ff1 fs1 fc1 sc1 ls0 ws0">例：DCB<span class="_ _5"></span>dcb;</div><div class="t m0 x8 h3 y3f ff1 fs1 fc1 sc1 ls0 ws0">BuildCommDCB("COM1:2400,n,8,1",<span class="_ _5"></span>&dcb);</div><div class="t m0 x8 h3 y40 ff1 fs1 fc1 sc1 ls0 ws0">SetCommState(&dcb);</div><div class="t m0 x3 h3 y41 ff1 fs1 fc1 sc1 ls0 ws0">③<span class="_ _5"></span>ReadComm<span class="_ _5"></span>、WriteComm()对串口进行读写操作，即数据的接收和发送.</div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611926,0.000000,0.000000,1.611926,0.000000,0.000000]}'></div></div>

<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/bg3.jpg"><div class="t m0 x9 h3 y26 ff1 fs1 fc1 sc1 ls0 ws0">例：char<span class="_ _5"></span>*m_pRecieve;<span class="_ _5"></span>int<span class="_ _5"></span>count;</div><div class="t m0 xa h3 y42 ff1 fs1 fc1 sc1 ls0 ws0">ReadComm(idComDev,m_pRecieve,count);</div><div class="t m0 xa h3 y43 ff1 fs1 fc1 sc1 ls0 ws0">Char<span class="_ _5"></span>wr[30];<span class="_ _5"></span>int<span class="_ _5"></span>count2;</div><div class="t m0 xa h3 y44 ff1 fs1 fc1 sc1 ls0 ws0">WriteComm(idComDev,wr,count2);</div><div class="t m0 x4 h3 y2b ff1 fs1 fc1 sc1 ls0 ws0">16<span class="_ _4"></span>位下的串口通信程序最大的特点就在于：串口等外部设备的操作有自己</div><div class="t m0 x3 h3 y2c ff1 fs1 fc1 sc1 ls0 ws0">特有的<span class="_ _4"></span>API<span class="_ _4"></span>函数；而<span class="_ _4"></span>32<span class="_ _4"></span>位程序则把串口操作（以及并口等）和文件操作统一起</div><div class="t m0 x3 h3 y2d ff1 fs1 fc1 sc1 ls0 ws0">来了，使用类似的操作。</div><div class="t m0 x3 h3 y45 ff1 fs1 fc1 sc2 ls0 ws0">四．在<span class="_ _4"></span>MF<span class="_ _1"></span>C<span class="_ _4"></span>下的<span class="_ _4"></span>32<span class="_ _4"></span>位串口应<span class="_ _1"></span>用程序</div><div class="t m0 x4 h3 y46 ff1 fs1 fc1 sc1 ls0 ws0">32<span class="_ _4"></span>位下串口通信程序可以用两种方法实现：利用<span class="_ _4"></span>ActiveX<span class="_ _4"></span>控件；使用<span class="_ _4"></span>API</div><div class="t m0 x3 h3 y47 ff1 fs1 fc1 sc1 ls0 ws0">通信函数。</div><div class="t m0 x4 h3 y48 ff1 fs1 fc1 sc1 ls0 ws0">使用<span class="_ _4"></span>ActiveX<span class="_ _4"></span>控件，程序实现非常简单，结构清晰，缺点是欠灵活；使用</div><div class="t m0 x3 h3 y49 ff1 fs1 fc1 sc1 ls0 ws0">API<span class="_ _5"></span>通信函数的优缺点则基本上相反。</div><div class="t m0 x3 h3 y4a ff1 fs1 fc1 sc1 ls0 ws0">以下介绍的都是在单文档（SDI）应用程序中加入串口通信能力的程序。</div><div class="t m0 x3 h3 y4b ff1 fs1 fc1 sc2 ls0 ws0">㈠<span class="_ _5"></span>使用<span class="_ _4"></span>Acti<span class="_ _1"></span>veX<span class="_ _4"></span>控件：</div><div class="t m0 x4 h3 y4c ff1 fs1 fc1 sc1 ls0 ws0">VC++<span class="_ _5"></span>6.0<span class="_ _6"></span>提供的<span class="_ _3"></span>MSComm<span class="_ _6"></span>控件通过串行端口发送和接收数据，为应用程序提</div><div class="t m0 x3 h3 y4d ff1 fs1 fc1 sc1 ls0 ws0">供串行通信功能。使用非常方便，但可惜的是，很少有介绍<span class="_ _4"></span>MSComm<span class="_ _4"></span>控件的资</div><div class="t m0 x3 h3 y4e ff1 fs1 fc1 sc1 ls0 ws0">料。</div><div class="t m0 x4 h3 y4f ff1 fs1 fc1 sc2 ls0 ws0">⑴．在当前的<span class="_ _4"></span>Wo<span class="_ _1"></span>rkspac<span class="_ _1"></span>e<span class="_ _4"></span>中插入<span class="_ _4"></span>MSCo<span class="_ _1"></span>mm<span class="_ _4"></span>控件。</div><div class="t m0 x3 h3 y50 ff1 fs1 fc1 sc1 ls0 ws0">Project<span class="_ _4"></span>菜单------>Add<span class="_ _5"></span>to<span class="_ _5"></span>Project---->Components<span class="_ _5"></span>and<span class="_ _5"></span>Controls-----</div><div class="t m0 x3 h3 y51 ff1 fs1 fc1 sc1 ls0 ws0">>Registered<span class="_ _5"></span>ActiveX<span class="_ _5"></span>Controls--->选择<span class="_ _4"></span>Components:<span class="_ _5"></span>Microsoft</div><div class="t m0 x3 h3 y52 ff1 fs1 fc1 sc1 ls0 ws0">Communications<span class="_ _5"></span>Control,version<span class="_ _5"></span>6.0<span class="_ _5"></span>插入到当前的<span class="_ _4"></span>Workspace<span class="_ _4"></span>中。结果添加</div><div class="t m0 x3 h3 y53 ff1 fs1 fc1 sc1 ls0 ws0">了类<span class="_ _4"></span>CMSComm(及相应文件：mscomm.h<span class="_ _4"></span>和<span class="_ _4"></span>mscomm.cpp<span class="_ _5"></span>)。</div><div class="t m0 x4 h3 y54 ff1 fs1 fc1 sc2 ls0 ws0">⑵．在<span class="_ _4"></span>Main<span class="_ _1"></span>Frm.<span class="_ _1"></span>h<span class="_ _4"></span>中加入<span class="_ _4"></span>MSComm<span class="_ _4"></span>控件<span class="_ _1"></span>。</div><div class="t m0 x3 h3 y55 ff1 fs1 fc1 sc1 ls0 ws0">protected:</div><div class="t m0 x9 h3 y56 ff1 fs1 fc1 sc1 ls0 ws0">CMSComm<span class="_ _5"></span>m_ComPort;</div><div class="t m0 x3 h3 y57 ff1 fs1 fc1 sc1 ls0 ws0">在<span class="_ _4"></span>Mainfrm.cpp::OnCreare()中：</div><div class="t m0 x4 h3 y58 ff1 fs1 fc1 sc1 ls0 ws0">DWORD<span class="_ _5"></span>style=WS_VISIBLE|WS_CHILD;</div><div class="t m0 x9 h3 y59 ff1 fs1 fc1 sc1 ls0 ws0">if</div><div class="t m0 xb h3 y5a ff1 fs1 fc1 sc1 ls0 ws0">(!m_ComPort.Create(NULL,style,CRect(0,0,0,0),this,ID_COMMCTRL)){</div><div class="t m0 xc h3 y5b ff1 fs1 fc1 sc1 ls0 ws0">TRACE0("Failed<span class="_ _5"></span>to<span class="_ _5"></span>create<span class="_ _5"></span>OLE<span class="_ _5"></span>Communications<span class="_ _5"></span>Control\n");</div><div class="t m0 xc h3 y5c ff1 fs1 fc1 sc1 ls0 ws0">return<span class="_ _5"></span>-1;<span class="_ _7"></span>//<span class="_ _5"></span>fail<span class="_ _5"></span>to<span class="_ _5"></span>create</div><div class="t m0 xd h3 y5d ff1 fs1 fc1 sc1 ls0 ws0">}</div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611926,0.000000,0.000000,1.611926,0.000000,0.000000]}'></div></div>

<div id="pf4" class="pf w0 h0" data-page-no="4"><div class="pc pc4 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/bg4.jpg"><div class="t m0 x4 h3 y25 ff1 fs1 fc1 sc2 ls0 ws0">⑶.初始化串<span class="_ _1"></span>口</div><div class="t m0 xe h3 y5e ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetCommPort(1);<span class="_ _8"></span>//选择<span class="_ _4"></span>COM1</div><div class="t m0 x8 h3 y5f ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.<span class="_ _5"></span>SetInBufferSize(1024);<span class="_ _5"></span>//设置输入缓冲区的大小，Bytes</div><div class="t m0 x8 h3 y60 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.<span class="_ _5"></span>SetOutBufferSize(512);<span class="_ _5"></span>//设置输入缓冲区的大小，Bytes//</div><div class="t m0 x8 h3 y61 ff1 fs1 fc1 sc1 ls0 ws0">if(!m_ComPort.GetPortOpen())<span class="_ _5"></span>//打开串口</div><div class="t m0 x8 h3 y62 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetPortOpen(TRUE);</div><div class="t m0 x8 h3 y63 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetInputMode(1);<span class="_ _5"></span>//设置输入方式为二进制方式</div><div class="t m0 x8 h3 y64 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetSettings("9600,n,8,1");<span class="_ _5"></span>//设置波特率等参数</div><div class="t m0 x8 h3 y65 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetRThreshold(1);<span class="_ _5"></span>//为<span class="_ _4"></span>1<span class="_ _4"></span>表示有一个字符引发一个事件</div><div class="t m0 x8 h3 y66 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetInputLen(0);</div><div class="t m0 x3 h3 y67 ff1 fs1 fc1 sc2 ls0 ws0">⑷．捕捉串口事<span class="_ _1"></span>项。</div><div class="t m0 x4 h3 y68 ff1 fs1 fc1 sc1 ls0 ws0">MSComm<span class="_ _4"></span>控件可以采用轮询或事件驱动的方法从端口获取数据。我们介绍比</div><div class="t m0 x3 h3 y69 ff1 fs1 fc1 sc1 ls0 ws0">较使用的事件驱动方法：有事件（如接收到数据）时通知程序。在程序中需要</div><div class="t m0 x3 h3 y6a ff1 fs1 fc1 sc1 ls0 ws0">捕获并处理这些通讯事件。</div><div class="t m0 x3 h3 y6b ff1 fs1 fc1 sc1 ls0 ws0">在<span class="_ _4"></span>MainFrm.h<span class="_ _4"></span>中：</div><div class="t m0 xf h3 y6c ff1 fs1 fc1 sc1 ls0 ws0">protected:</div><div class="t m0 xf h3 y6d ff1 fs1 fc1 sc1 ls0 ws0">afx_msg<span class="_ _5"></span>void<span class="_ _5"></span>OnCommMscomm();</div><div class="t m0 xf h3 y6e ff1 fs1 fc1 sc1 ls0 ws0">DECLARE_EVENTSINK_MAP()</div><div class="t m0 xf h3 y6f ff1 fs1 fc1 sc1 ls0 ws0">在<span class="_ _4"></span>MainFrm.cpp<span class="_ _4"></span>中：</div><div class="t m0 xf h3 y70 ff1 fs1 fc1 sc1 ls0 ws0">BEGIN_EVENTSINK_MAP(CMainFrame,CFrameWnd<span class="_ _5"></span>)</div><div class="t m0 xf h3 y71 ff1 fs1 fc1 sc1 ls0 ws0">ON_EVENT(CMainFrame,ID_COMMCTRL,1,OnCommMscomm,VTS_NONE)<span class="_ _9"></span>//映射</div><div class="t m0 xf h3 y72 ff1 fs1 fc1 sc1 ls0 ws0">ActiveX<span class="_ _4"></span>控件事件</div><div class="t m0 xf h3 y73 ff1 fs1 fc1 sc1 ls0 ws0">END_EVENTSINK_MAP()</div><div class="t m0 x3 h3 y74 ff1 fs1 fc1 sc2 ls0 ws0">⑸．串口读写<span class="_ _1"></span>.</div><div class="t m0 x4 h3 y75 ff1 fs1 fc1 sc1 ls0 ws0">完成读写的函数的确很简单，GetInput()和<span class="_ _4"></span>SetOutput()就可。两个函数</div><div class="t m0 x3 h3 y76 ff1 fs1 fc1 sc1 ls0 ws0">的原型是：</div><div class="t m0 x3 h3 y77 ff1 fs1 fc1 sc1 ls0 ws0">VARIANT<span class="_ _5"></span>GetInput()；及<span class="_ _5"></span>void<span class="_ _5"></span>SetOutput(const<span class="_ _5"></span>VARIANT&<span class="_ _5"></span>newValue);都要使</div><div class="t m0 x3 h3 y78 ff1 fs1 fc1 sc1 ls0 ws0">用<span class="_ _4"></span>VARIANT<span class="_ _4"></span>类型（所有<span class="_ _4"></span>Idispatch::Invoke<span class="_ _4"></span>的参数和返回值在内部都是作为</div><div class="t m0 x3 h3 y79 ff1 fs1 fc1 sc1 ls0 ws0">VARIANT<span class="_ _4"></span>对象处理的）。</div><div class="t m0 x4 h3 y7a ff1 fs1 fc1 sc1 ls0 ws0">无论是在<span class="_ _2"></span>PC<span class="_ _3"></span>机读取上传数据时还是在<span class="_ _2"></span>PC<span class="_ _3"></span>机发送下行命令时，我们都习惯于</div><div class="t m0 x3 h3 y7b ff1 fs1 fc1 sc1 ls0 ws0">使用字符串的形式（也可以说是数组形式）。查阅<span class="_ _4"></span>VARIANT<span class="_ _4"></span>文档知道，可以用</div><div class="t m0 x3 h3 y7c ff1 fs1 fc1 sc1 ls0 ws0">BSTR<span class="_ _6"></span>表示字符串，但遗憾的是所有的<span class="_ _3"></span>BSTR<span class="_ _6"></span>都是包含宽字符，即使我们没有定义</div><div class="t m0 x3 h3 y7d ff1 fs1 fc1 sc1 ls0 ws0">_UNICODE_UNICODE<span class="_ _4"></span>也是这样！<span class="_ _5"></span>WinNT<span class="_ _4"></span>支持宽字符,<span class="_ _5"></span>而<span class="_ _4"></span>Win95<span class="_ _4"></span>并不支持。为解决</div><div class="t m0 x3 h3 y7e ff1 fs1 fc1 sc1 ls0 ws0">上述问题，我们在实际工作中使用<span class="_ _4"></span>CbyteArray，给出相应的部分程序如下：</div><div class="t m0 xc h3 y7f ff1 fs1 fc1 sc1 ls0 ws0">void<span class="_ _5"></span>CMainFrame::OnCommMscomm(){</div><div class="t m0 x10 h3 y80 ff1 fs1 fc1 sc1 ls0 ws0">VARIANT<span class="_ _5"></span>vResponse;<span class="_ _7"></span>int<span class="_ _5"></span>k;</div><div class="t m0 x11 h3 y81 ff1 fs1 fc1 sc1 ls0 ws0">if(m_commCtrl.GetCommEvent()==2)<span class="_ _5"></span>{</div></div><div class="pi" data-data='{"ctm":[1.611926,0.000000,0.000000,1.611926,0.000000,0.000000]}'></div></div>

<div id="pf5" class="pf w0 h0" data-page-no="5"><div class="pc pc5 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/62741ab9f0a4f84830c85a4a/bg5.jpg"><div class="t m0 x12 h3 y82 ff1 fs1 fc1 sc1 ls0 ws0">k=m_commCtrl.GetInBufferCount();<span class="_ _5"></span>//接收到的字符数目</div><div class="t m0 x12 h3 y83 ff1 fs1 fc1 sc1 ls0 ws0">if(k>0)<span class="_ _5"></span>{</div><div class="t m0 x12 h3 y84 ff1 fs1 fc1 sc1 ls0 ws0">vResponse=m_commCtrl.GetInput();<span class="_ _5"></span>//read</div><div class="t m0 x12 h3 y85 ff1 fs1 fc1 sc1 ls0 ws0">SaveData(k,(unsigned<span class="_ _5"></span>char*)<span class="_ _5"></span>vResponse.parray->pvData);</div><div class="t m0 x13 h3 y86 ff1 fs1 fc1 sc1 ls0 ws0">}<span class="_ _5"></span>//<span class="_ _5"></span>接收到字符，MSComm<span class="_ _4"></span>控件发送事件<span class="_ _5"></span>}</div><div class="t m0 x14 h3 y87 ff1 fs1 fc1 sc1 ls0 ws0">。。。。。<span class="_ _5"></span>//<span class="_ _5"></span>处理其他<span class="_ _4"></span>MSComm<span class="_ _4"></span>控件</div><div class="t m2 x15 h3 y88 ff1 fs1 fc1 sc1 ls0 ws0">}</div><div class="t m0 x16 h3 y89 ff1 fs1 fc1 sc1 ls0 ws0">void<span class="_ _5"></span>CMainFrame::OnCommSend()<span class="_ _5"></span>{</div><div class="t m0 x14 h3 y8a ff1 fs1 fc1 sc1 ls0 ws0">。。。。。。。。<span class="_ _5"></span>//<span class="_ _5"></span>准备需要发送的命令，放在<span class="_ _4"></span>TxData[]中</div><div class="t m0 x13 h3 y8b ff1 fs1 fc1 sc1 ls0 ws0">CByteArray<span class="_ _5"></span>array;</div><div class="t m0 x13 h3 y8c ff1 fs1 fc1 sc1 ls0 ws0">array.RemoveAll();</div><div class="t m0 x13 h3 y8d ff1 fs1 fc1 sc1 ls0 ws0">array.SetSize(Count);</div><div class="t m0 x13 h3 y8e ff1 fs1 fc1 sc1 ls0 ws0">for(i=0;i<Count;i++)</div><div class="t m0 x13 h3 y8f ff1 fs1 fc1 sc1 ls0 ws0">array.SetAt(i,<span class="_ _5"></span>TxData[i]);</div><div class="t m0 x17 h3 y90 ff1 fs1 fc1 sc1 ls0 ws0">m_ComPort.SetOutput(COleVariant(array));<span class="_ _5"></span>//<span class="_ _5"></span>发送数据</div><div class="t m0 x16 h3 y91 ff1 fs1 fc1 sc1 ls0 ws0">}</div><div class="t m0 x3 h3 y92 ff1 fs1 fc1 sc1 ls0 ws0">请大家认真关注第⑷、⑸中内容，在实际工作中是重点、难点所在。</div><div class="t m0 x3 h3 y93 ff1 fs1 fc1 sc2 ls0 ws0">㈡<span class="_ _5"></span>使用<span class="_ _4"></span>32<span class="_ _4"></span>位<span class="_ _1"></span>的<span class="_ _4"></span>API<span class="_ _5"></span>通信函数<span class="_ _1"></span>:</div><div class="t m0 x3 h3 y94 ff1 fs1 fc1 sc1 ls0 ws0">可能很多朋友会觉得奇怪：用<span class="_ _4"></span>32<span class="_ _4"></span>位<span class="_ _4"></span>API<span class="_ _4"></span>函数编写串口通信程序，不就是把<span class="_ _4"></span>16</div><div class="t m0 x3 h3 y95 ff1 fs1 fc1 sc1 ls0 ws0">位的<span class="_ _4"></span>API<span class="_ _4"></span>换成<span class="_ _4"></span>32<span class="_ _4"></span>位吗？16<span class="_ _4"></span>位的串口通信程序可是多年之前就有很多人研讨过</div><div class="t m0 x3 h3 y96 ff1 fs1 fc1 sc1 ls0 ws0">了……</div><div class="t m0 x3 h3 y97 ff1 fs1 fc1 sc1 ls0 ws0">此文主要想介绍一下在<span class="_ _4"></span>API<span class="_ _4"></span>串口通信中如何结合非阻塞通信、多线程等手段，</div><div class="t m0 x3 h3 y98 ff1 fs1 fc1 sc1 ls0 ws0">编写出高质量的通信程序。特别是在<span class="_ _4"></span>CPU<span class="_ _4"></span>处理任务比较繁重、与外围设备中有</div><div class="t m0 x3 h3 y99 ff1 fs1 fc1 sc1 ls0 ws0">大量的通信数据时，更有实际意义。</div><div class="t m0 x3 h3 y9a ff1 fs1 fc1 sc2 ls0 ws0">⑴．在中<span class="_ _4"></span>M<span class="_ _1"></span>ainFrm<span class="_ _1"></span>.cpp<span class="_ _4"></span>定义全局变量</div></div><div class="pi" data-data='{"ctm":[1.611926,0.000000,0.000000,1.611926,0.000000,0.000000]}'></div></div>