查看“Micro:bit系列教程16：Infrared Proximity”的源代码

<p class="MsoNormal" style="line-height:150%"><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">本章将介绍Infrared Proximity Sensor（红外接近传感器），主要用于检测前方是否有障碍物。<span lang="EN-US"></span></span></p>
<h1 style="line-height:150%"><span lang="EN-US" style="font-size:15.0pt;
line-height:150%;font-family:黑体;font-weight:normal;mso-bidi-font-weight:bold">1.</span><span style="font-size:15.0pt;line-height:150%;font-family:黑体;font-weight:normal;
mso-bidi-font-weight:bold">基本介绍<span lang="EN-US"></span></span></h1>
<p class="MsoNormal" style="line-height:150%"><span lang="EN-US">    </span><span lang="EN-US" style="font-size:
12.0pt;line-height:150%;font-family:宋体">Infrared Proximity Sensor</span><span style="font-size:12.0pt;line-height:150%;font-family:宋体">是一款红外接近器模块，该模块能发射红外线，<span lang="EN-US"></span></span></p>
<p class="MsoNormal" style="line-height:150%"><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">也能接收反射回来的红外线，并反馈前方是否有障碍物。<span lang="EN-US"></span></span></p>
<p class="MsoNormal" style="line-height:150%"><span lang="EN-US" style="font-size:
12.0pt;line-height:150%;font-family:宋体">  </span><span style="font-size:12.0pt;line-height:150%;font-family:宋体">其主要原理为：红外发射管是由红外发光二极管矩组成发光体，用红外辐射效率高的材料（常用砷化镓）制成<span lang="EN-US"> PN </span>结，正向偏压向<span lang="EN-US"> PN </span>结注入电流激发红外光。红外接收管是将红外线光信号变成电信号的半导体器件，它的核心部件是一个特殊材料的<span lang="EN-US"> PN </span>结，随着红外光强度的增加电流也随之增大输出模拟信号。当检测方向遇到障碍物（反射面）时，红外线反射回来被接收管接收，经过<span lang="EN-US"> LM393 </span>比较器处理后输出数字信号，同时绿色指示灯点亮，可通过电位器旋钮调节检测距离。<span lang="EN-US"></span></span></p>
<h1 style="line-height:150%"><span lang="EN-US" style="font-size:15.0pt;
line-height:150%;font-family:黑体;font-weight:normal;mso-bidi-font-weight:bold">2.</span><span style="font-size:15.0pt;line-height:150%;font-family:黑体;font-weight:normal;
mso-bidi-font-weight:bold">硬件连接<span lang="EN-US"></span></span></h1>
<p class="MsoNormal" style="line-height:150%"><span lang="EN-US" style="font-size:
12.0pt;line-height:150%;font-family:宋体">  </span><span style="font-size:12.0pt;line-height:150%;font-family:宋体">在硬件上面，采用<span lang="EN-US">Micro:bit</span>的<span lang="EN-US">P0</span>引脚来采集模拟电压，并进行<span lang="EN-US">AD</span>转换，从而得到数字信号，采用<span lang="EN-US">Micro:bit</span>的<span lang="EN-US">P1</span>引脚连接<span lang="EN-US">Infrared Proximity Sensor</span>的数字输出来判断是否接近障碍物。<span lang="EN-US"></span></span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;line-height:
  150%;font-family:宋体">Micro:bit</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">Infrared Proximity Sensor</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">VCC</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">VCC</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">GND</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">GND</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">P0</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">AOUT</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">P1</span></p>
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<p align="center" class="MsoNormal" style="text-align:center;line-height:150%"><span lang="EN-US" style="font-size:12.0pt;
  line-height:150%;font-family:宋体">DOUT</span></p>
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<p class="MsoNormal" style="line-height:150%"><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">具体硬件连接如下图所示：<span lang="EN-US"></span></span></p>
<p>[[File:Micro：bit系列教程16：Infrared_Proximity_Sensor红外障碍物检测-0.jpg|400px]]</p>
<h1 style="line-height:150%"><span lang="EN-US" style="font-size:15.0pt;
line-height:150%;font-family:黑体;font-weight:normal;mso-bidi-font-weight:bold">3.</span><span style="font-size:15.0pt;line-height:150%;font-family:黑体;font-weight:normal;
mso-bidi-font-weight:bold">软件设计<span lang="EN-US"></span></span></h1>
<p class="MsoNormal" style="line-height:150%"><span lang="EN-US">    </span><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">打开<span lang="EN-US">makecode</span>，添加软件包，输入链接：<span lang="EN-US"></span></span></p>
<p class="MsoNormal" style="line-height:150%"><span lang="EN-US"><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">https://github.com/waveshare/CourseKit</span></span><span class="MsoHyperlink"><span lang="EN-US" style="font-size:12.0pt;line-height:150%;
font-family:宋体"></span></span></p>
<p class="MsoNormal" style="line-height:150%"><span style="font-size:12.0pt;
line-height:150%;font-family:宋体">添加软件包成功后，采用积木块编写以下程序：<span lang="EN-US"></span></span></p>
<p>[[File:Micro：bit系列教程16：Infrared_Proximity_Sensor红外障碍物检测-1.png|400px]]</p>
<p class="MsoNormal" style="text-indent:21.0pt;line-height:150%"><span style="font-size:12.0pt;line-height:150%;font-family:宋体">下载，点击显示数据<span lang="EN-US">(</span>设备<span lang="EN-US">)</span>按钮，将显示采集到<span lang="EN-US">Infrared
Proximity Sensor</span>的原始<span lang="EN-US">ADC</span>值，转换后的电压，以及是否靠近障碍物等，具体数据如下图所示：<span lang="EN-US"></span></span></p>
<p>[[File:Micro：bit系列教程16：Infrared_Proximity_Sensor红外障碍物检测-2.png|400px]]</p>
<span mso-bidi-theme-font:minor-bidi="" new="" roman="" style="font-size:12.0pt;font-family:宋体;mso-bidi-font-family:" times="" zh-cn="">当传感器靠近障碍物时，模块上的信号提示灯点亮；传感器远离障碍物时，模块上的信号指示灯熄灭。随着传感器与障碍物距离的变化，串口输出的<span lang="EN-US">ADC</span>值和转换后的电压值均会发生相应的变化。</span>