<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://csdnimg.cn/release/download_crawler_static/css/base.min.css"><link rel="stylesheet" href="https://csdnimg.cn/release/download_crawler_static/css/fancy.min.css"><link rel="stylesheet" href="https://csdnimg.cn/release/download_crawler_static/4542536/raw.css"><script src="https://csdnimg.cn/release/download_crawler_static/js/compatibility.min.js"></script><script src="https://csdnimg.cn/release/download_crawler_static/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://csdnimg.cn/release/download_crawler_static/4542536/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"></div><div class="t m0 x2 h3 y2 ff2 fs1 fc0 sc1 ls1 ws0">重庆邮电大学电子制作大赛 </div><div class="t m0 x1 h3 y3 ff2 fs1 fc0 sc1 ls0 ws0"> </div><div class="t m0 x3 h4 y4 ff2 fs2 fc0 sc1 ls2 ws0">设 </div><div class="t m0 x1 h4 y5 ff2 fs2 fc0 sc1 ls0 ws0"> </div><div class="t m0 x3 h4 y6 ff2 fs2 fc0 sc1 ls2 ws0">计 </div><div class="t m0 x1 h4 y7 ff2 fs2 fc0 sc1 ls0 ws0"> </div><div class="t m0 x3 h4 y8 ff2 fs2 fc0 sc1 ls2 ws0">报 </div><div class="t m0 x1 h4 y9 ff2 fs2 fc0 sc1 ls0 ws0"> </div><div class="t m0 x3 h4 ya ff2 fs2 fc0 sc1 ls2 ws0">告 </div><div class="t m0 x1 h5 yb ff2 fs3 fc0 sc0 ls3 ws0"> </div><div class="t m0 x4 h5 yc ff2 fs3 fc0 sc0 ls0 ws0">学院：<span class="ls4"> 自动化学院 </span></div><div class="t m0 x5 h5 yd ff2 fs3 fc0 sc0 ls0 ws0"> </div><div class="t m0 x4 h5 ye ff2 fs3 fc0 sc0 ls0 ws0">年级：<span class="ls5"> 09<span class="_ _0"> </span>级 </span></div><div class="t m0 x6 h5 yf ff2 fs3 fc0 sc0 ls6 ws0"> </div><div class="t m0 x4 h5 y10 ff2 fs3 fc0 sc0 ls0 ws0">姓名：<span class="ls7"> 钟军 </span></div><div class="t m0 x7 h5 y11 ff2 fs3 fc0 sc0 ls8 ws0"> 姓名：<span class="ls3"> 田涛 <span class="ls9"> 姓名：<span class="lsa"> 向鹏 <span class="lsb"> </span></span></span></span></div><div class="t m0 x4 h5 y12 ff2 fs3 fc0 sc0 ls0 ws0">学号：<span class="_ _1"></span><span class="ls5"> 2009212407 </span></div><div class="t m0 x8 h5 y13 ff2 fs3 fc0 sc0 ls4 ws0"> 学号：<span class="_ _1"></span><span class="ls6"> 2009212399 <span class="ls0">学号：<span class="_ _1"></span><span class="ls8"> 2009212411 <span class="_ _2"></span><span class="lsc"> </span></span></span></span></div><div class="t m0 x4 h5 y14 ff2 fs3 fc0 sc0 ls0 ws0">班级：<span class="_ _3"></span><span class="ls8"> 0830904 </span></div><div class="t m0 x9 h5 y15 ff2 fs3 fc0 sc0 ls6 ws0"> 班级：<span class="_ _3"></span> 0810901 <span class="ls0">班级：<span class="_ _3"></span><span class="lsd"> 0810901 <span class="_"> </span><span class="ls9"> </span></span></span></div><div class="t m0 xa h5 y16 ff2 fs3 fc0 sc1 lse ws0">摘要：</div><div class="t m0 xb h6 y17 ff2 fs4 fc0 sc0 ls0 ws0">科技发展，<span class="_ _4"></span>很多工业化的生产都需要温度测量，<span class="_ _4"></span>这使得温度测量仪器变成一个</div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></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://csdnimg.cn/release/download_crawler_static/4542536/bg2.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"></div><div class="t m0 x4 h6 y18 ff2 fs4 fc0 sc0 ls0 ws0">很重要的东西。<span class="_ _3"></span>根据题目中所给出的测量精度与测量范围，<span class="_ _3"></span>我们设计了一个又<span class="_ _5"> </span><span class="ff3 lsf">pt100<span class="_ _6"> </span></span>为温度</div><div class="t m0 x4 h6 y19 ff2 fs4 fc0 sc0 ls0 ws0">传感器的电路，<span class="ff3 ls10">p<span class="_ _1"></span>t100<span class="_ _5"> </span><span class="ff2 ls0">将环境的温度变化转化为自身电阻的变化，电路中采用了两个分压电</span></span></div><div class="t m0 x4 h6 y1a ff2 fs4 fc0 sc0 ls0 ws0">路，<span class="_ _3"></span>将电阻的转化为电压的变化，<span class="_ _3"></span>但电压的变化是非常微小的，<span class="_ _3"></span>我们将所采集到的电压变化</div><div class="t m0 x4 h6 y1b ff2 fs4 fc0 sc0 ls0 ws0">用运放做了一个电压跟随，<span class="_ _3"></span>然后经差动放大，<span class="_ _3"></span>得到了一个较大的电压输出。<span class="_ _3"></span>最后将这个输出</div><div class="t m0 x4 h6 y1c ff2 fs4 fc0 sc0 ls0 ws0">的电压送入一个自带<span class="_ _0"> </span><span class="ff3 ls11">AD<span class="_ _0"> </span></span>转换功能的<span class="_ _0"> </span><span class="ff3 ls12">ST<span class="_ _1"></span>C12C5A60S2<span class="_ _0"> </span><span class="ff2 ls0">单片机，经单片机软件处理后得去了环</span></span></div><div class="t m0 x4 h6 y1d ff2 fs4 fc0 sc0 ls0 ws0">境温度，<span class="_ _3"></span>并且在<span class="_ _6"> </span><span class="ff3 ls13">LCD160<span class="_ _1"></span>2<span class="_ _5"> </span><span class="ff2 ls0">中显示出来了。<span class="_ _3"></span>另外，<span class="_ _7"></span>针对题目中所要求的门限报警功能，<span class="_ _3"></span>我们将</span></span></div><div class="t m0 x4 h6 y1e ff2 fs4 fc0 sc0 ls0 ws0">三个按键接到单片机的三个<span class="_ _5"> </span><span class="ff3 ls14">I/O<span class="_ _6"> </span></span>口上，用来调节报警门限，报警十分迅速。<span class="ff1"></span></div><div class="t m0 xa h7 y1f ff2 fs3 fc0 sc1 lse ws0">关键词：<span class="ff3 fs4 sc0 ls10">pt100<span class="ff2 ls0">，差动放大，门限报警<span class="ff4 fs3"> </span></span></span></div><div class="t m0 xc h8 y20 ff5 fs5 fc0 sc0 ls0 ws0"></div><div class="t m0 xc h9 y21 ff6 fs5 fc0 sc0 ls0 ws0">I<span class="ff2 sc1 ls15">．电路分析</span><span class="ff5"></span></div><div class="t m0 x4 ha y22 ff1 fs4 fc0 sc0 ls16 ws0"><span class="_ _8"> </span><span class="ls0"></span></div><div class="t m0 xd h6 y23 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">1<span class="_"> </span><span class="ff1"></span></span></div><div class="t m0 xe h6 y24 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">1<span class="_ _6"> </span></span>为<span class="_ _6"> </span><span class="ff3 ls17">multisim<span class="_ _5"> </span></span>中仿真用的电路图，<span class="_ _9"></span>接下来以分析此电路图来说明本次电路设计中的温</div><div class="t m0 x4 h6 y25 ff2 fs4 fc0 sc0 ls0 ws0">度采样原理。<span class="ff1"></span></div><div class="t m0 xe h6 y26 ff2 fs4 fc0 sc0 ls0 ws0">电路中的<span class="_ _5"> </span><span class="ff3 ls18">R1,R3,R4,</span>为<span class="_ _6"> </span><span class="ff3 ls10">100<span class="_ _5"> </span></span>欧姆的精密电阻，<span class="_ _4"></span>由于<span class="_ _6"> </span><span class="ff3 ls19">Pt10<span class="_ _1"></span>0<span class="_ _6"> </span><span class="ff2 ls0">的电阻<span class="_ _1"></span>是随环境温度变化的，<span class="_ _4"></span>在</span></span></div><div class="t m0 x4 h6 y27 ff2 fs4 fc0 sc0 ls0 ws0">仿真时可又用一个可调电阻来代替热敏电阻，通过调节可调电阻可以得到不同的输出电压。</div><div class="t m0 x4 h6 y28 ff2 fs4 fc0 sc0 ls0 ws0">经<span class="_ _5"> </span><span class="ff3 ls1a">L<span class="_ _a"></span>M258AD<span class="_ _6"> </span></span>电压跟随后，<span class="_ _b"></span>送到另一个由<span class="_ _5"> </span><span class="ff3 ls1a">L<span class="_ _a"></span>M258AD<span class="_ _6"> </span></span>构成的比例差动运算放大器，<span class="_ _b"></span>将两个分压</div><div class="t m0 x4 h6 y29 ff2 fs4 fc0 sc0 ls0 ws0">电路的分压差放大输出，当环境温度为<span class="_ _5"> </span><span class="ff3">0<span class="_ _6"> </span></span>度时，<span class="_ _1"></span><span class="ff3 ls1b">pt100<span class="_ _6"> </span><span class="ff2 ls0">为<span class="_ _5"> </span></span><span class="ls1c">100<span class="_ _6"> </span><span class="ff2 ls0">欧姆，<span class="_ _1"></span>两个分压电路的分压输</span></span></span></div><div class="t m0 x4 h6 y2a ff2 fs4 fc0 sc0 ls0 ws0">出均为<span class="_ _5"> </span><span class="ff3 ls1d">2.5V</span>，<span class="_ _3"></span>若运放为理想放大器时，<span class="_ _9"></span>此时的输出应该为<span class="_ _6"> </span><span class="ff3">0</span>，<span class="_ _9"></span>当环境温度大于<span class="_ _5"> </span><span class="ff3">0<span class="_ _6"> </span></span>度时，<span class="_ _9"></span><span class="ff3 ls10">pt100</span></div><div class="t m0 x4 h6 y2b ff2 fs4 fc0 sc0 ls0 ws0">的阻值将大于<span class="_ _5"> </span><span class="ff3 ls10">100<span class="_ _6"> </span></span>欧姆，<span class="_ _b"></span>比例差动运算放大器的同相输入与反相输入不再相等，<span class="_ _c"></span>此时由运放</div><div class="t m0 x4 h6 y2c ff2 fs4 fc0 sc0 ls0 ws0">可以得到一个较大的电压差。<span class="ff1"></span></div><div class="t m0 x4 h6 y2d ff5 fs4 fc0 sc0 ls0 ws0"><span class="_ _d"> </span><span class="ff2">电压输出关于<span class="_ _5"> </span><span class="ff3 ls1b">pt<span class="_ _a"></span>100<span class="_ _6"> </span></span>电阻变化的计算过程如下：<span class="ff1"></span></span></div><div class="t m0 x4 ha y2e ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 xf hb y2f ff7 fs6 fc0 sc0 ls0 ws0">4</div><div class="t m0 x10 hb y30 ff7 fs6 fc0 sc0 ls1e ws0">12</div><div class="t m0 x11 hb y31 ff7 fs6 fc0 sc0 ls1f ws0">3</div><div class="t m0 x12 hc y32 ff7 fs7 fc0 sc0 ls0 ws0">,</div><div class="t m0 x13 hd y33 ff8 fs6 fc0 sc0 ls20 ws0">pt</div><div class="t m0 x14 hd y34 ff8 fs6 fc0 sc0 ls21 ws0">vcc<span class="_ _e"> </span>vcc</div><div class="t m0 x15 he y35 ff8 fs7 fc0 sc0 ls0 ws0">R</div><div class="t m0 x16 he y36 ff8 fs7 fc0 sc0 ls0 ws0">R</div><div class="t m0 x17 he y37 ff8 fs7 fc0 sc0 ls22 ws0">uu<span class="_ _f"> </span>u<span class="_ _10"></span>u</div><div class="t m0 x18 hb y38 ff7 fs6 fc0 sc0 ls1f ws0">14<span class="_ _11"></span><span class="ff8 ls20">pt</span></div><div class="c x19 y39 w2 hf"><div class="t m0 x0 he y3a ff8 fs7 fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x1a he y3b ff8 fs7 fc0 sc0 ls23 ws0">RR<span class="_ _12"></span><span class="ff9 ls24"></span></div><div class="t m0 x1b h10 y3c ff7 fs8 fc0 sc0 ls25 ws0">56<span class="_ _13"> </span>78</div><div class="t m0 x1c h11 y3d ff7 fs9 fc0 sc0 ls26 ws0">10<span class="_ _14"> </span>,<span class="_ _15"> </span>91</div><div class="t m0 x1d he y3b ff8 fs7 fc0 sc0 ls23 ws0">R</div><div class="t m0 x1e h12 y3e ff9 fs7 fc0 sc0 ls27 ws0"><span class="_ _16"></span><span class="ffa ls28"></span></div><div class="t m0 x1f h6 y3f ff2 fs4 fc0 sc0 ls0 ws0">，<span class="ff1 ls29"><span class="_ _17"></span><span class="ff2 ls0">（<span class="ff3">1</span>）<span class="ff1"></span></span></span></div><div class="t m0 x4 h6 y40 ff2 fs4 fc0 sc0 ls0 ws0">取</div><div class="c x20 y41 w3 h13"><div class="t m0 x0 h14 y42 ff8 fs9 fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x21 h14 y3d ff8 fs9 fc0 sc0 ls2a ws0">RK<span class="_ _18"></span>R<span class="_ _19"></span>R<span class="_ _1"></span>K<span class="_ _1a"></span><span class="ff9 ls2b"><span class="_ _1b"> </span><span class="_ _1c"> </span><span class="_ _1"></span><span class="_ _1b"> </span><span class="_ _1d"></span><span class="ff2 fs4 ls0">，则<span class="ff1"></span></span></span></div><div class="t m0 x22 h15 y43 ff7 fsa fc0 sc0 ls0 ws0">7</div><div class="t m0 x23 h15 y44 ff7 fsa fc0 sc0 ls2c ws0">12</div><div class="t m0 x22 h15 y45 ff7 fsa fc0 sc0 ls0 ws0">5</div><div class="t m0 x24 h16 y46 ff7 fsb fc0 sc0 ls2d ws0">()</div><div class="t m0 x25 h17 y47 ff8 fsa fc0 sc0 ls2e ws0">out</div><div class="c x26 y48 w4 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x27 h18 y46 ff8 fsb fc0 sc0 ls2f ws0">uu<span class="_ _1e"></span>u</div><div class="c x26 y49 w5 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">R</div></div><div class="t m0 xa h19 y46 ff9 fsb fc0 sc0 ls30 ws0"><span class="_ _3"></span><span class="ffa fsc ls0"></span></div><div class="t m0 x28 h6 y4a ff1 fs4 fc0 sc0 ls31 ws0"><span class="_ _a"></span><span class="_ _a"></span><span class="_ _a"></span><span class="_ _a"></span><span class="ff2 ls0">（<span class="ff3">2</span>）<span class="ff1"></span></span></div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></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://csdnimg.cn/release/download_crawler_static/4542536/bg3.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"></div><div class="t m0 x4 h6 y18 ff2 fs4 fc0 sc0 ls0 ws0">由（<span class="ff3">1</span>）<span class="_ _1f"></span>（<span class="ff3">2</span>）可得：<span class="ff1"></span></div><div class="t m0 x4 ha y4b ff1 fs4 fc0 sc0 ls29 ws0"></div><div class="t m0 x29 h15 y4c ff7 fsa fc0 sc0 ls0 ws0">7</div><div class="t m0 x2a h15 y4d ff7 fsa fc0 sc0 ls0 ws0">4</div><div class="t m0 x2b h15 y4e ff7 fsa fc0 sc0 ls32 ws0">14<span class="_ _3"></span>3<span class="_ _b"></span>5</div><div class="t m0 x2c h16 y4f ff7 fsb fc0 sc0 ls33 ws0">()</div><div class="t m0 x2d h17 y50 ff8 fsa fc0 sc0 ls34 ws0">pt</div><div class="t m0 x2e h17 y51 ff8 fsa fc0 sc0 ls34 ws0">vcc</div><div class="t m0 x2f h17 y52 ff8 fsa fc0 sc0 ls34 ws0">pt</div><div class="t m0 x30 h18 y53 ff8 fsb fc0 sc0 ls0 ws0">R</div><div class="c x31 y54 w6 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x32 h17 y55 ff8 fsa fc0 sc0 ls34 ws0">out</div><div class="t m0 x33 h18 y56 ff8 fsb fc0 sc0 ls0 ws0">R</div><div class="t m0 x19 h18 y57 ff8 fsb fc0 sc0 ls35 ws0">uu</div><div class="c x34 y58 w7 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x8 h18 y59 ff8 fsb fc0 sc0 ls36 ws0">RR<span class="_ _1"></span>R<span class="_ _3"></span>R</div><div class="t m0 x13 h19 y5a ff9 fsb fc0 sc0 ls37 ws0"></div><div class="t m0 x35 h19 y59 ff9 fsb fc0 sc0 ls38 ws0"></div><div class="t m0 x36 h1a y4f ffa fs7 fc0 sc0 ls0 ws0"></div><div class="t m0 x37 h6 y5b ff1 fs4 fc0 sc0 ls29 ws0"><span class="_ _17"></span><span class="ff2 ls0">（<span class="ff3">3</span>）<span class="ff1"></span></span></div><div class="t m0 x4 h6 y5c ff2 fs4 fc0 sc0 ls0 ws0">代入具体数值后可得：<span class="ff1"></span></div><div class="t m0 x38 h16 y5d ff7 fsb fc0 sc0 ls39 ws0">100</div><div class="t m0 x39 h16 y5e ff7 fsb fc0 sc0 ls3a ws0">5(</div><div class="t m0 x3a h16 y5f ff7 fsb fc0 sc0 ls39 ws0">100<span class="_ _20"> </span>100<span class="_ _14"> </span>100</div><div class="t m0 x3b h17 y60 ff8 fsa fc0 sc0 ls34 ws0">pt</div><div class="t m0 x32 h17 y61 ff8 fsa fc0 sc0 ls3b ws0">out</div><div class="t m0 x3c h17 y62 ff8 fsa fc0 sc0 ls34 ws0">pt</div><div class="t m0 x3d h18 y63 ff8 fsb fc0 sc0 ls0 ws0">R</div><div class="t m0 x3e h16 y64 ff7 fsb fc0 sc0 ls39 ws0">91</div><div class="t m0 x3f h16 y5e ff7 fsb fc0 sc0 ls3a ws0">)</div><div class="t m0 x40 h16 y5f ff7 fsb fc0 sc0 ls39 ws0">10</div><div class="c x41 y65 w8 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">K</div></div><div class="t m0 x19 h18 y66 ff8 fsb fc0 sc0 ls3c ws0">uV</div><div class="c x42 y67 w9 hf"><div class="t m0 x0 h18 y42 ff8 fsb fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x41 h18 y68 ff8 fsb fc0 sc0 ls0 ws0">K</div><div class="c x29 y65 wa h1b"><div class="t m0 x0 h19 y42 ff9 fsb fc0 sc0 ls0 ws0"></div></div><div class="t m0 x43 h19 y5d ff9 fsb fc0 sc0 ls0 ws0"></div><div class="t m0 x44 h19 y5f ff9 fsb fc0 sc0 ls3d ws0"><span class="_ _21"> </span></div><div class="t m0 x45 h1a y66 ffa fs7 fc0 sc0 ls3e ws0"></div><div class="t m0 x46 h1c y69 ff8 fsd fc0 sc0 ls0 ws0">V</div><div class="t m0 x13 h19 y6a ff9 fsb fc0 sc0 ls3f ws0"></div><div class="t m0 x9 h19 y6b ff9 fsb fc0 sc0 ls3d ws0"></div><div class="t m0 x38 h19 y5f ff9 fsb fc0 sc0 ls3d ws0"><span class="_ _22"></span></div><div class="t m0 x47 h6 y6c ff1 fs4 fc0 sc0 ls40 ws0"><span class="_ _23"> </span><span class="ff2 ls0">（<span class="ff3">4</span>）<span class="ff1"><span class="_ _24"></span><span class="ls29"></span></span></span></div><div class="t m0 xa h6 y6d ff2 fs4 fc0 sc0 ls0 ws0">为了使得去的电压输出更为精确，</div><div class="t m0 x48 h1d y69 ff7 fsd fc0 sc0 ls0 ws0">5</div><div class="t m0 x38 h6 y6e ff2 fs4 fc0 sc0 ls0 ws0">的电压用<span class="_ _5"> </span><span class="ff3 ls41">78<span class="_ _a"></span>05<span class="_ _6"> </span></span>稳压输出，<span class="_ _7"></span>如图<span class="_ _5"> </span><span class="ff3">2</span>，<span class="_ _7"></span>相关电阻均采</div><div class="t m0 x4 h6 y6f ff2 fs4 fc0 sc0 ls0 ws0">用精密电阻。<span class="ff1"></span></div><div class="t m0 x49 ha y70 ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x4a h6 y71 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">2<span class="_"> </span></span>，稳压电路<span class="ff1"></span></div><div class="t m0 xa h6 y72 ff2 fs4 fc0 sc0 ls0 ws0">经以上分析，<span class="_ _b"></span>我们说明了整个采样电路的原理，<span class="_ _c"></span>下面则要分析所采集的模拟电压是如何</div><div class="t m0 x4 h6 y73 ff2 fs4 fc0 sc0 ls0 ws0">经控制器处理后得去所要测量的温度的。<span class="ff1"></span></div><div class="t m0 x4 h6 y74 ff1 fs4 fc0 sc0 ls0 ws0"><span class="_ _d"> </span><span class="ff2">一般说来，<span class="_ _b"></span>所检测的模拟信号，<span class="_ _c"></span>如本设计中的电压信号都要经过模数转换得去数字信号</span></div><div class="t m0 x4 h6 y75 ff2 fs4 fc0 sc0 ls0 ws0">后才能被单片机运算处理，<span class="_ _b"></span>得到温度输出。<span class="_ _c"></span>但在设计电路时考虑到尽可能的降低电路的复杂</div><div class="t m0 x4 h6 y76 ff2 fs4 fc0 sc0 ls0 ws0">程度，我们选择了一个自带<span class="_ _5"> </span><span class="ff3 ls42">ADC<span class="_ _6"> </span></span>功能的单片机<span class="_ _5"> </span><span class="ff3 ls18">STC12C5A60S2,</span><span class="ff1"></span></div><div class="t m0 x4 h6 y77 ff1 fs4 fc0 sc0 ls0 ws0"><span class="_ _d"> </span><span class="ff3 ls12">ST<span class="_ _1"></span>C12C5A60S2<span class="_ _5"> </span><span class="ff2 ls0">系列单片机自带的<span class="_ _6"> </span></span><span class="ls18">A/D<span class="_ _5"> </span><span class="ff2 ls0">转换口在<span class="_ _6"> </span></span><span class="ls43">P1.0~P1.7<span class="_ _6"> </span><span class="ff2 ls0">口，有<span class="_ _5"> </span><span class="ff3">8<span class="_ _6"> </span></span>路<span class="_ _5"> </span></span><span class="ls10">10<span class="_ _6"> </span><span class="ff2 ls44">位调整<span class="_ _6"> </span></span></span></span>A/D<span class="_ _5"> </span><span class="ff2 ls0">转</span></span></span></div><div class="t m0 x4 h6 y78 ff2 fs4 fc0 sc0 ls0 ws0">换器，<span class="_ _25"></span>速度可达到<span class="_ _5"> </span><span class="ff3 ls1c">25<span class="_ _6"> </span></span>万次<span class="ff3">/</span>秒，<span class="_ _25"></span>可作温度检测，<span class="_ _25"></span>电压检测，<span class="_ _25"></span>按键扫描，<span class="_ _25"></span>频谱检测。<span class="_ _25"></span><span class="ff3 ls45">ST<span class="_ _1"></span>C12C5A60S2</span></div><div class="t m0 x4 h6 y79 ff2 fs4 fc0 sc0 ls0 ws0">系列单片机<span class="_ _6"> </span><span class="ff3 ls42">ADC<span class="_ _26"> </span></span>由多路选择开关，比较器，逐次比较寄存器，<span class="ff3 ls10">10<span class="_ _6"> </span></span>位<span class="_ _26"> </span><span class="ff3 ls46">DAC</span>，转换结果存储寄</div><div class="t m0 x4 h6 y7a ff2 fs4 fc0 sc0 ls0 ws0">存器（<span class="ff3 ls47">ADC_RES,</span><span class="ff1"><span class="ff3 ls47">ADC_RESL</span></span>）组成。<span class="ff1"></span></div><div class="t m0 x4 h6 y7b ff1 fs4 fc0 sc0 ls0 ws0"><span class="_ _d"> </span><span class="ff2">通过软件设置可以将<span class="_ _5"> </span><span class="ff3 ls48">P1.0<span class="_ _6"> </span></span>口设置为模拟量输入通道，<span class="_ _27"></span>然后经<span class="_ _5"> </span><span class="ff3 ls42">ADC<span class="_ _6"> </span></span>转换后将<span class="_ _5"> </span><span class="ff3 ls10">10<span class="_ _6"> </span></span>位数字量</span></div><div class="t m0 x4 h6 y7c ff2 fs4 fc0 sc0 ls0 ws0">储存在结果存储寄存器中，<span class="_ _3"></span>其中结果的高<span class="_ _5"> </span><span class="ff3">8<span class="_ _6"> </span></span><span class="ls44">位在<span class="_ _6"> </span><span class="ff3 ls49">ADC_RES<span class="_ _5"> </span></span></span>中，<span class="_ _3"></span>低<span class="_ _6"> </span><span class="ff3">2<span class="_ _5"> </span></span><span class="ls44">位在<span class="_ _6"> </span><span class="ff3 ls47">ADC_RESL<span class="_ _5"> </span></span></span>的低<span class="_ _6"> </span><span class="ff3">2<span class="_ _5"> </span></span>位</div><div class="t m0 x4 h6 y7d ff2 fs4 fc0 sc0 ls0 ws0">中，<span class="_ _3"></span>此时得到的结果还只是从采样电路中获取的电压信号，<span class="_ _3"></span>我们根据采样的原理，<span class="_ _3"></span>按电压与</div><div class="t m0 x4 h6 y7e ff2 fs4 fc0 sc0 ls0 ws0">电阻的关系，<span class="_ _3"></span>将电压信号转化为电阻信号，<span class="_ _3"></span>这个可又通过算法计算得到。<span class="_ _3"></span>最后再将计算出的</div><div class="t m0 x4 h6 y7f ff3 fs4 fc0 sc0 ls10 ws0">pt100<span class="_ _5"> </span><span class="ff2 ls0">电阻值转化为当时的环境温度，<span class="_ _27"></span>由于在<span class="_ _6"> </span><span class="ff3">0<span class="_ _5"> </span></span>到<span class="_ _6"> </span><span class="ff3 ls1c">40<span class="_ _6"> </span></span>度范围内<span class="_ _5"> </span><span class="ff3 ls4a">pt1<span class="_ _a"></span>00<span class="_ _6"> </span></span>的电阻与温度有相当好</span></div><div class="t m0 x4 h6 y80 ff2 fs4 fc0 sc0 ls0 ws0">的线性关系，即，<span class="_ _28"> </span>，其中</div><div class="t m0 x1f h1e y81 ff7 fse fc0 sc0 ls0 ws0">3</div><div class="t m0 x4b h1e y82 ff7 fse fc0 sc0 ls0 ws0">0</div><div class="t m0 x30 h1f y83 ff7 fsf fc0 sc0 ls4b ws0">(<span class="_ _7"></span>1<span class="_ _29"> </span>3.97<span class="_ _2a"> </span>10<span class="_ _2b"> </span>)</div><div class="t m0 x4c h20 y84 ff8 fse fc0 sc0 ls4c ws0">pt</div><div class="t m0 x4d h21 y83 ff8 fsf fc0 sc0 ls4d ws0">RR<span class="_ _2c"> </span>t</div><div class="t m0 x4e h22 y81 ff9 fse fc0 sc0 ls0 ws0"></div><div class="t m0 x12 h23 y83 ff9 fsf fc0 sc0 ls4e ws0"><span class="_ _4"></span></div><div class="t m0 x4f h10 y84 ff7 fs8 fc0 sc0 ls0 ws0">0</div><div class="t m0 x50 h11 y83 ff7 fs9 fc0 sc0 ls0 ws0">100<span class="_ _2d"></span><span class="ff8">R</span></div><div class="c x51 y85 wb h24"><div class="t m0 x0 h25 y42 ff9 fs9 fc0 sc0 ls0 ws0"></div></div><div class="t m0 x52 h6 y83 ff9 fs9 fc0 sc0 ls0 ws0"><span class="_ _5"> </span><span class="ff2 fs4">，为<span class="_ _6"> </span><span class="ff3 ls10">pt100<span class="_ _26"> </span></span>在<span class="_ _26"> </span><span class="ff3">0<span class="_ _0"> </span></span>度时候的电</span></div><div class="t m0 x4 h6 y86 ff2 fs4 fc0 sc0 ls0 ws0">阻，<span class="_ _9"></span>显然，</div><div class="t m0 x4d h26 y87 ff7 fs10 fc0 sc0 ls0 ws0">0</div><div class="t m0 x12 h27 y88 ff7 fs11 fc0 sc0 ls0 ws0">1</div><div class="t m0 x53 h27 y89 ff7 fs11 fc0 sc0 ls4f ws0">3.97</div><div class="t m0 x54 h28 y8a ff8 fs10 fc0 sc0 ls50 ws0">pt</div><div class="t m0 x55 h29 y8b ff8 fs11 fc0 sc0 ls0 ws0">R</div><div class="t m0 x56 h29 y8c ff8 fs11 fc0 sc0 ls0 ws0">R</div><div class="t m0 x57 h2a y8d ff9 fs11 fc0 sc0 ls0 ws0"></div><div class="t m0 x58 h2a y8e ff9 fs11 fc0 sc0 ls0 ws0"></div><div class="t m0 x7 h26 y8f ff7 fs10 fc0 sc0 ls0 ws0">3</div><div class="t m0 x59 h27 y89 ff7 fs11 fc0 sc0 ls4f ws0">10</div><div class="t m0 x2c h2b y90 ff9 fs10 fc0 sc0 ls0 ws0"></div><div class="t m0 x5a h29 y91 ff8 fs11 fc0 sc0 ls0 ws0">t</div><div class="c x28 y92 wc h2c"><div class="t m0 x0 h2a y93 ff9 fs11 fc0 sc0 ls0 ws0"></div></div><div class="t m0 x4b h6 y94 ff2 fs4 fc0 sc0 ls0 ws0">，<span class="_ _9"></span>按此线性关系即可得到最后的温度。<span class="_ _9"></span>由于这些变量都是浮点数，</div><div class="t m0 x4 h6 y95 ff2 fs4 fc0 sc0 ls0 ws0">因此，<span class="_ _b"></span>在程序设计时都将它们定义成了浮点数，<span class="_ _c"></span><span class="ff3 ls45">STC12C5A60S2<span class="_ _5"> </span><span class="ff2 ls0">的运算速度比<span class="_ _6"> </span></span><span class="ls51">A<span class="_ _7"></span>T89c52<span class="_ _5"> </span><span class="ff2 ls0">要快<span class="_ _6"> </span><span class="ff3">6</span></span></span></span></div><div class="t m0 x4 h6 y96 ff2 fs4 fc0 sc0 ls0 ws0">倍以上，因此，浮点运算不影响单片机的工作效率。<span class="ff1"></span></div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></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://csdnimg.cn/release/download_crawler_static/4542536/bg4.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"></div><div class="t m0 x5b ha y97 ff5 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x5c h6 y98 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">3<span class="_"> </span></span>，主控制器电路<span class="ff1"></span></div><div class="t m0 xa h6 y99 ff2 fs4 fc0 sc0 ls0 ws0">主控制器的外围电路设计完全可又参照最小单片机系统电路的设计，由于<span class="_ _6"> </span><span class="ff3 ls52">P0<span class="_ _6"> </span></span>口是三态</div><div class="t m0 x4 h6 y9a ff2 fs4 fc0 sc0 ls0 ws0">输出的，因此设计时要为<span class="_ _5"> </span><span class="ff3 ls52">P0<span class="_ _6"> </span></span>口加上上拉电阻。<span class="ff1"></span></div><div class="t m0 x5d ha y9b ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x5e h6 y9c ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">4<span class="_"> </span></span>，按键连接图<span class="ff1"></span></div><div class="t m0 xa h6 y9d ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">4<span class="_ _6"> </span></span>中的三个按键都分别并联有一个滤波电容，<span class="_ _27"></span>这样可又很好的将按键被按下时所产生</div><div class="t m0 x4 h6 y9e ff2 fs4 fc0 sc0 ls0 ws0">的抖动信号滤除掉，再加上软件的延时防抖，按键的设计变得更加完善。<span class="ff1"></span></div><div class="t m0 x5f ha y9f ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x60 h6 ya0 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">5<span class="_"> </span></span>，<span class="ff3 ls53">lcd<span class="_ _6"> </span></span>显示部分原理图<span class="ff1"></span></div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></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://csdnimg.cn/release/download_crawler_static/4542536/bg5.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"></div><div class="t m0 xa h6 ya1 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">5<span class="_ _6"> </span></span>中</div><div class="t m0 xb h10 ya2 ff7 fs8 fc0 sc0 ls54 ws0">15</div><div class="c x61 ya3 w4 h13"><div class="t m0 x0 h14 y42 ff8 fs9 fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x62 h6 ya1 ff2 fs4 fc0 sc0 ls0 ws0">为<span class="_ _5"> </span><span class="ff3 ls13">LCD1602<span class="_ _5"> </span></span>背光限流电阻，</div><div class="t m0 x31 h2d ya4 ff7 fs12 fc0 sc0 ls55 ws0">13</div><div class="c xd ya3 w4 h2e"><div class="t m0 x0 h2f ya5 ff8 fs13 fc0 sc0 ls0 ws0">R</div></div><div class="t m0 x63 h6 ya1 ff2 fs4 fc0 sc0 ls0 ws0">用来调节<span class="_ _5"> </span><span class="ff3 ls56">LC<span class="_ _a"></span>D<span class="_ _6"> </span></span>显示的对比度。<span class="ff1"></span></div><div class="t m0 x64 ha ya6 ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x2b h6 ya7 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">6<span class="_"> </span></span>，报警部分线路原理图<span class="ff1"></span></div><div class="t m0 x65 ha ya8 ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 x66 h6 ya9 ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">7<span class="_"> </span></span>，供电部分线路图<span class="ff1"></span></div><div class="t m0 xa h6 yaa ff2 fs4 fc0 sc0 ls0 ws0">图<span class="_ _5"> </span><span class="ff3">7<span class="_ _6"> </span></span>中的<span class="_ _5"> </span><span class="ff3 ls57">LED<span class="_ _6"> </span></span>为电源供电指示灯，<span class="ff3 ls58">C1<span class="_ _6"> </span></span>与<span class="_ _5"> </span><span class="ff3 ls58">C2<span class="_ _6"> </span></span>为滤波电容。<span class="ff1"></span></div><div class="t m0 xc h9 yab ff6 fs5 fc0 sc0 ls59 ws0">2.<span class="ff2 sc1 ls5a">程序设计</span><span class="ff5 ls0"></span></div><div class="t m0 x24 h30 yac ff3 fs14 fc0 sc0 ls5b ws0">(1)LCD160<span class="_ _1"></span>2<span class="_ _0"> </span><span class="ff2 ls0">的显示程序<span class="ff1 fs4"></span></span></div><div class="t m0 xa h6 yad ff2 fs4 fc0 sc0 ls0 ws0">我们将该部分写成了一个专门的头文件，<span class="_ _25"></span>包含该头文件后用一个函数即可将所要的结果</div><div class="t m0 x4 h6 yae ff2 fs4 fc0 sc0 ls5c ws0">在显示器上显示出来，<span class="_ _1"></span>并且可又很灵活的控制显示的<span class="_ _1"></span>位置。头文件名为<span class="_"> </span><span class="ff3 ls5d">lcd160<span class="_ _1"></span>2.h<span class="ff2 ls5c">，具体程</span></span></div><div class="t m0 x4 h6 yaf ff2 fs4 fc0 sc0 ls0 ws0">序代码如下：<span class="ff1"></span></div><div class="t m0 xa h31 yb0 ff3 fs4 fc0 sc0 ls53 ws0">#ifndef<span class="ff1 ls0"></span><span class="ls42">LCD_CHAR_160<span class="_ _1"></span>2<span class="ff1 ls0"></span></span></div><div class="t m0 xa h31 yb1 ff3 fs4 fc0 sc0 ls43 ws0">#define<span class="ff1 ls0"></span><span class="ls5d">LCD_CHAR_160<span class="_ _1"></span>2<span class="ff1 ls0"></span></span></div><div class="t m0 xa ha yb2 ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 xa h31 yb3 ff3 fs4 fc0 sc0 ls5e ws0">#include<span class="ff1 ls0"></span><span class="ls49"><intrins.h><span class="ff1 ls0"></span></span></div><div class="t m0 xa ha yb4 ff1 fs4 fc0 sc0 ls0 ws0"></div><div class="t m0 xa h31 yb5 ff3 fs4 fc0 sc0 ls1d ws0">//P<span class="_ _1"></span>ort<span class="ff1 ls0"></span><span class="ls5f">Definitions****************************<span class="_"> </span>**<span class="_ _a"></span>**********************<span class="_ _a"></span>******<span class="ff1 ls0"></span></span></div><div class="t m0 xa h31 yb6 ff3 fs4 fc0 sc0 ls60 ws0">sbit<span class="ff1 ls0"></span><span class="ls5d">LcdRs<span class="ff1 ls61"></span><span class="ls0">=<span class="ff1"></span><span class="ls45">P2^6;</span><span class="ff1"></span></span></span></div><div class="t m0 xa h31 yb7 ff3 fs4 fc0 sc0 ls60 ws0">sbit<span class="ff1 ls0"></span><span class="ls12">LcdRw<span class="ff1 ls62"><span class="_ _26"> </span></span><span class="ls0">=<span class="ff1"></span><span class="ls45">P2^5;</span><span class="ff1"></span></span></span></div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></div></div>
