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class="container" id="main-content" tabindex="-1"><div class="post"><article class="post-block h-entry"><div class="post-meta p-author h-card visually-hidden"><img class="author-avatar u-photo" src="../favicon.png" alt="Cytrogen"><span class="p-name">Cytrogen</span><a class="u-url" href="https://cytrogen.icu">https://cytrogen.icu</a></div><a class="post-permalink u-url u-uid visually-hidden" href="https://cytrogen.icu/posts/ba6a.html">永久链接</a><div class="p-summary visually-hidden"><p>如何使用 MicroPython 在树莓派 Pico 上通过有源蜂鸣器播放音频。</p></div><div class="visually-hidden"><a class="p-category" href="../categories/%E7%BC%96%E7%A8%8B%E7%AC%94%E8%AE%B0/">编程笔记</a><a class="p-category" href="../tags/Python/">Python</a><a class="p-category" href="../tags/%E6%A0%91%E8%8E%93%E6%B4%BE/">树莓派</a></div><h1 class="post-title p-name">树莓派 Pico 通过有源蜂鸣器播放音频</h1><div class="post-info"><time class="post-date dt-published" datetime="2023-05-15T22:49:48.000Z">5/15/2023</time><time class="dt-updated visually-hidden" datetime="2026-02-09T17:16:55.401Z"></time></div><div class="post-content e-content"><html><head></head><body><p>如何使用 MicroPython 在树莓派 Pico 上通过有源蜂鸣器播放音频。</p>
<span id="more"></span>
<h1 id="目录"><a class="markdownIt-Anchor" href="#目录"></a> 目录</h1>
<ul>
<li><a href="#%E7%9B%AE%E5%BD%95">目录</a></li>
<li><a href="#%E5%89%8D%E8%A8%80">前言</a></li>
<li><a href="#%E5%87%86%E5%A4%87">准备</a>
<ul>
<li><a href="#%E5%AF%BC%E5%85%A5%E5%BA%93">导入库</a></li>
<li><a href="#%E9%9F%B3%E7%AC%A6%E4%B8%8E%E9%A2%91%E7%8E%87">音符与频率</a>
<ul>
<li><a href="#%E9%A2%98%E5%A4%96%E8%AF%9D">题外话</a></li>
</ul>
</li>
<li><a href="#%E8%AE%BE%E7%BD%AE%E8%9C%82%E9%B8%A3%E5%99%A8">设置蜂鸣器</a></li>
</ul>
</li>
<li><a href="#%E7%BC%96%E5%86%99%E4%BB%A3%E7%A0%81">编写代码</a>
<ul>
<li><a href="#%E8%8E%B7%E5%8F%96%E4%B9%90%E8%B0%B1">获取乐谱</a></li>
<li><a href="#%E6%92%AD%E6%94%BE%E9%9F%B3%E9%A2%91">播放音频</a></li>
<li><a href="#%E6%92%AD%E6%94%BE%E4%B9%90%E8%B0%B1">播放乐谱</a></li>
</ul>
</li>
<li><a href="#%E6%9C%80%E7%BB%88%E6%95%88%E6%9E%9C">最终效果</a></li>
</ul>
<center> ————————</center>
<h1 id="前言"><a class="markdownIt-Anchor" href="#前言"></a> 前言</h1>
<p>我的树莓派 Pico 早在过年时就到手了，但是一直没有时间玩，最近闲到开始生一种叫做 senioritis 的病，才开始捣鼓起来。</p>
<p>买的时候贪方便，直接购入了已焊接的板子，如下图所示：</p>
<img src="/posts/ba6a/1.jpeg" alt="创乐博MAKEROBO PicoBlock扩展板，已焊接树莓派Pico主板、面包板、LED灯、方向按键、有源蜂鸣器、传感器等套件">
<p>不过本文内容专注于 MicroPython，所以不会细讲硬件部分。如何配置树莓派 Pico 和安装 IDE 等基础内容也不会讲，可以自行搜索。</p>
<div class="danger">
<ul>
<li>本文使用的 IDE 为 Thonny</li>
<li>本文乐谱均来自于 <a target="_blank" rel="noopener" href="https://onlinesequencer.net/">Online Sequencer</a> 这个网站</li>
</ul>
</div>
<center>————————</center>
<h1 id="准备"><a class="markdownIt-Anchor" href="#准备"></a> 准备</h1>
<h2 id="导入库"><a class="markdownIt-Anchor" href="#导入库"></a> 导入库</h2>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> time</span><br><span class="line"><span class="keyword">from</span> machine <span class="keyword">import</span> PWM, Pin</span><br></pre></td></tr></tbody></table></figure>
<ul>
<li><code>time</code> 库自不用多说，是用来延时的</li>
<li><code>machine</code> 库则包含了和特定电路板上的硬件有关的方法，例如我们刚刚导入的 <code>PWM</code> 和 <code>Pin</code>。详细的内容可以参考 <a target="_blank" rel="noopener" href="https://docs.micropython.org/en/latest/library/machine.html">MicroPython 官方文档</a></li>
</ul>
<h2 id="音符与频率"><a class="markdownIt-Anchor" href="#音符与频率"></a> 音符与频率</h2>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br></pre></td><td class="code"><pre><span class="line">tones = {</span><br><span class="line"> <span class="string">'C0'</span>: <span class="number">16</span>, <span class="string">'C#0'</span>: <span class="number">17</span>, <span class="string">'D0'</span>: <span class="number">18</span>, <span class="string">'D#0'</span>: <span class="number">19</span>, <span class="string">'E0'</span>: <span class="number">21</span>, <span class="string">'F0'</span>: <span class="number">22</span>,</span><br><span class="line"> <span class="string">'F#0'</span>: <span class="number">23</span>, <span class="string">'G0'</span>: <span class="number">24</span>, <span class="string">'G#0'</span>: <span class="number">26</span>, <span class="string">'A0'</span>: <span class="number">28</span>, <span class="string">'A#0'</span>: <span class="number">29</span>, <span class="string">'B0'</span>: <span class="number">31</span>,</span><br><span class="line"> <span class="string">'C1'</span>: <span class="number">33</span>, <span class="string">'C#1'</span>: <span class="number">35</span>, <span class="string">'D1'</span>: <span class="number">37</span>, <span class="string">'D#1'</span>: <span class="number">39</span>, <span class="string">'E1'</span>: <span class="number">41</span>, <span class="string">'F1'</span>: <span class="number">44</span>,</span><br><span class="line"> <span class="string">'F#1'</span>: <span class="number">46</span>, <span class="string">'G1'</span>: <span class="number">49</span>, <span class="string">'G#1'</span>: <span class="number">52</span>, <span class="string">'A1'</span>: <span class="number">55</span>, <span class="string">'A#1'</span>: <span class="number">58</span>, <span class="string">'B1'</span>: <span class="number">62</span>,</span><br><span class="line"> <span class="string">'C2'</span>: <span class="number">65</span>, <span class="string">'C#2'</span>: <span class="number">69</span>, <span class="string">'D2'</span>: <span class="number">73</span>, <span class="string">'D#2'</span>: <span class="number">78</span>, <span class="string">'E2'</span>: <span class="number">82</span>, <span class="string">'F2'</span>: <span class="number">87</span>,</span><br><span class="line"> <span class="string">'F#2'</span>: <span class="number">92</span>, <span class="string">'G2'</span>: <span class="number">98</span>, <span class="string">'G#2'</span>: <span class="number">104</span>, <span class="string">'A2'</span>: <span class="number">110</span>, <span class="string">'A#2'</span>: <span class="number">117</span>, <span class="string">'B2'</span>: <span class="number">123</span>,</span><br><span class="line"> <span class="string">'C3'</span>: <span class="number">131</span>, <span class="string">'C#3'</span>: <span class="number">139</span>, <span class="string">'D3'</span>: <span class="number">147</span>, <span class="string">'D#3'</span>: <span class="number">156</span>, <span class="string">'E3'</span>: <span class="number">165</span>, <span class="string">'F3'</span>: <span class="number">175</span>,</span><br><span class="line"> <span class="string">'F#3'</span>: <span class="number">185</span>, <span class="string">'G3'</span>: <span class="number">196</span>, <span class="string">'G#3'</span>: <span class="number">208</span>, <span class="string">'A3'</span>: <span class="number">220</span>, <span class="string">'A#3'</span>: <span class="number">233</span>, <span class="string">'B3'</span>: <span class="number">247</span>,</span><br><span class="line"> <span class="string">'C4'</span>: <span class="number">262</span>, <span class="string">'C#4'</span>: <span class="number">277</span>, <span class="string">'D4'</span>: <span class="number">294</span>, <span class="string">'D#4'</span>: <span class="number">311</span>, <span class="string">'E4'</span>: <span class="number">330</span>, <span class="string">'F4'</span>: <span class="number">349</span>,</span><br><span class="line"> <span class="string">'F#4'</span>: <span class="number">370</span>, <span class="string">'G4'</span>: <span class="number">392</span>, <span class="string">'G#4'</span>: <span class="number">415</span>, <span class="string">'A4'</span>: <span class="number">440</span>, <span class="string">'A#4'</span>: <span class="number">466</span>, <span class="string">'B4'</span>: <span class="number">494</span>,</span><br><span class="line"> <span class="string">'C5'</span>: <span class="number">523</span>, <span class="string">'C#5'</span>: <span class="number">554</span>, <span class="string">'D5'</span>: <span class="number">587</span>, <span class="string">'D#5'</span>: <span class="number">622</span>, <span class="string">'E5'</span>: <span class="number">659</span>, <span class="string">'F5'</span>: <span class="number">698</span>,</span><br><span class="line"> <span class="string">'F#5'</span>: <span class="number">740</span>, <span class="string">'G5'</span>: <span class="number">784</span>, <span class="string">'G#5'</span>: <span class="number">831</span>, <span class="string">'A5'</span>: <span class="number">880</span>, <span class="string">'A#5'</span>: <span class="number">932</span>, <span class="string">'B5'</span>: <span class="number">988</span>,</span><br><span class="line"> <span class="string">'C6'</span>: <span class="number">1047</span>, <span class="string">'C#6'</span>: <span class="number">1109</span>, <span class="string">'D6'</span>: <span class="number">1175</span>, <span class="string">'D#6'</span>: <span class="number">1245</span>, <span class="string">'E6'</span>: <span class="number">1319</span>, <span class="string">'F6'</span>: <span class="number">1397</span>,</span><br><span class="line"> <span class="string">'F#6'</span>: <span class="number">1480</span>, <span class="string">'G6'</span>: <span class="number">1568</span>, <span class="string">'G#6'</span>: <span class="number">1661</span>, <span class="string">'A6'</span>: <span class="number">1760</span>, <span class="string">'A#6'</span>: <span class="number">1865</span>, <span class="string">'B6'</span>: <span class="number">1976</span>,</span><br><span class="line"> <span class="string">'C7'</span>: <span class="number">2093</span>, <span class="string">'C#7'</span>: <span class="number">2217</span>, <span class="string">'D7'</span>: <span class="number">2349</span>, <span class="string">'D#7'</span>: <span class="number">2489</span>, <span class="string">'E7'</span>: <span class="number">2637</span>, <span class="string">'F7'</span>: <span class="number">2794</span>,</span><br><span class="line"> <span class="string">'F#7'</span>: <span class="number">2960</span>, <span class="string">'G7'</span>: <span class="number">3136</span>, <span class="string">'G#7'</span>: <span class="number">3322</span>, <span class="string">'A7'</span>: <span class="number">3520</span>, <span class="string">'A#7'</span>: <span class="number">3729</span>, <span class="string">'B7'</span>: <span class="number">3951</span>,</span><br><span class="line"> <span class="string">'C8'</span>: <span class="number">4186</span>, <span class="string">'C#8'</span>: <span class="number">4435</span>, <span class="string">'D8'</span>: <span class="number">4699</span>, <span class="string">'D#8'</span>: <span class="number">4978</span>, <span class="string">'E8'</span>: <span class="number">5274</span>, <span class="string">'F8'</span>: <span class="number">5588</span>,</span><br><span class="line"> <span class="string">'F#8'</span>: <span class="number">5920</span>, <span class="string">'G8'</span>: <span class="number">6272</span>, <span class="string">'G#8'</span>: <span class="number">6645</span>, <span class="string">'A8'</span>: <span class="number">7040</span>, <span class="string">'A#8'</span>: <span class="number">7459</span>, <span class="string">'B8'</span>: <span class="number">7902</span>,</span><br><span class="line"> <span class="string">'C9'</span>: <span class="number">8372</span>, <span class="string">'C#9'</span>: <span class="number">8870</span>, <span class="string">'D9'</span>: <span class="number">9397</span>, <span class="string">'D#9'</span>: <span class="number">9956</span>, <span class="string">'E9'</span>: <span class="number">10548</span>, <span class="string">'F9'</span>: <span class="number">11175</span>,</span><br><span class="line"> <span class="string">'F#9'</span>: <span class="number">11840</span>, <span class="string">'G9'</span>: <span class="number">12544</span>, <span class="string">'G#9'</span>: <span class="number">13290</span>, <span class="string">'A9'</span>: <span class="number">14080</span>, <span class="string">'A#9'</span>: <span class="number">14917</span>, <span class="string">'B9'</span>: <span class="number">15804</span></span><br><span class="line">}</span><br></pre></td></tr></tbody></table></figure>
<p>这个字典包含了从 C0 到 B9 的所有音符的频率，单位为 Hz。这些频率之后会被用来设置 PWM 的频率。</p>
<h4 id="题外话"><a class="markdownIt-Anchor" href="#题外话"></a> 题外话</h4>
<p>如果不懂音符，但又想要照着现实中的乐谱来弹奏，那该怎么办？（当然，如果你懂的话，可以直接跳到 <a href="#%E8%AE%BE%E7%BD%AE%E8%9C%82%E9%B8%A3%E5%99%A8">这个位置</a>）</p>
<p>先来看看一个简单的乐谱长什么样子。有请我们的主角 ——《小星星》：</p>
<img src="/posts/ba6a/2.jpg" alt="小星星乐谱">
<p>首先，乐谱每一行都有数个小节，被竖线隔开。</p>
<p>每一行的最左边都有一个数字，代表了这一行的拍子。例如这个乐谱的拍子是 4 / 4 拍，也就是说每一小节有四拍，每一拍是一个四分音符。</p>
<p>那什么又是四分音符？这又要从音符的时值说起了。</p>
<p>音符的时值分为全音符、二分音符、四分音符、八分音符、十六分音符、三十二分音符等等。为了直接分辨，上图：</p>
<img src="/posts/ba6a/3.png" alt="圆圈，全音符，时值为4拍，简谱符号为1---；圆圈插一个天线，二分音符，时值为2拍，简谱符号为1-；黑圆圈插一个天线，四分音符，时值为1拍，简谱符号为1；黑圆圈插一个挂了旗子的天线，八分音符，时值为1/2拍，简谱符号为1.；黑圆圈插一个挂了俩旗子的天线，十六分音符，时值为1/4拍，简谱符号为1..；黑圆圈插一个挂了仨旗子的天线，三十二分音符，时值为1/8拍，简谱符号为1...；所有的.代表下划线">
<p>现在回到《小星星》的乐谱上，我们可以看到，第一小节正好有四个四分音符，而第二小节则有两个四分音符和一个二分音符：</p>
<img src="/posts/ba6a/4.jpg" alt="小星星简谱的第1小节和第2小节">
<p>那么在实际演奏中，这两个小节的区别是什么呢？</p>
<p>四个四分音符实际演奏：啊 啊 啊 啊；<br>
两个四分音符 & 一个二分音符实际演奏：啊 啊 啊 ——。</p>
<p>也就是说，在这个谱子里一个二分音符相当于把两个四分音符融合在一起，拉了个长音。</p>
<p>说完时值，现在来看五线谱中各个音符所处的位置。想必你也发现了，有些音符在线上、有些音符在线下、有些音符在中间、有些音符在上下两个线之间…… 这是为什么呢？</p>
<p>这又要说到音符的音高了。这里要注意一点，《小星星》的乐谱中标记了 1 = C，也就是 C 大调。C 大调由 C、D、E、F、G、A、B 七个音组成，况且还是唯一一个没有升降号的大调。</p>
<blockquote>
<p>钢琴上不是有白键和黑键吗？白键总体分为 C、D、E、F、G、A、B 七个音，而黑键总体分为 C#、D#、F#、G#、A# 五个音。<br>
# 符号代表了升号，也就是把这个音调提高半个音阶。比如 C# 是 C 的升半音，也是 C 和 D 之间的音。<br>
还有一个名为 b 的符号，代表了降号。和 #符号相反，b 符号是把这个音调降低半个音阶。Db 是 D 的降半音，是 C 和 D 之间的音，也是 C#。</p>
</blockquote>
<p>我们说了这么多 C、D、E、F、G、A、B，但是在《小星星》里，我们只看到了数字。这是因为在简谱中，用以表示音的高低的符号是阿拉伯数字。1 代表了 C，2 代表了 D，3 代表了 E，以此类推。</p>
<blockquote>
<p>而在现实生活中，我们最常使用的还是唱名，由 do、re、mi、fa、so、la、si 来表示音的高低。do 代表了 C，re 代表了 D，mi 代表了 E，以此类推。</p>
</blockquote>
<img src="/posts/ba6a/6.jpg" alt="阿拉伯数字、唱名、汉字的对照表">
<p>我们已经知道了如何用阿拉伯数字辨认音的高低，但是这仅能在简谱中使用。我们依旧还是要学会如何看五线谱。C 大调的音阶是这样的：</p>
<img src="/posts/ba6a/7.png" alt="C大调的音阶">
<p>来看《小星星》的第一小节。不需要看阿拉伯数字，这次也可以参照上一张图判断出这是 CCGG 了：</p>
<img src="/posts/ba6a/5.jpg" alt="小星星的第一小节，1155">
<p>但是在我们先前的 <a href="#%E9%9F%B3%E7%AC%A6%E4%B8%8E%E9%A2%91%E7%8E%87">音符对频率字典</a> 里，C、D、E、F、G、A、B 后面还跟了多个数字。比如 C4、C5、C6…… 这些数字代表了这个音的频率，也就是音的高低。C4 通常被认为是中央 C，C5 是高一个八度的 C，C6 是再高一个八度的 C，以此类推。</p>
<blockquote>
<p>八度指的是音的高低，在频率上是 2 倍的关系。比如 C4 的频率是 261.63Hz，C5 的频率是 523.25Hz，C6 的频率是 1046.50Hz，以此类推。<br>
不过我们不需要那么详细的小数，只要四舍五入到整数即可。</p>
</blockquote>
<p>为了方便，我们直接使用中央 C 作为基准，也就是 C4。这样，我们就可以把《小星星》的乐谱和音符结合起来了：</p>
<figure class="highlight plaintext"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">C4 C4 G4 G4 A4 A4 G4- F4 F4 E4 E4 D4 D4 C4- </span><br><span class="line">G4 G4 F4 F4 E4 E4 D4- G4 G4 F4 F4 E4 E4 D4- </span><br><span class="line">C4 C4 G4 G4 A4 A4 G4- F4 F4 E4 E4 D4 D4 C4-</span><br></pre></td></tr></tbody></table></figure>
<div class="danger">
这不是最终我们会使用的乐谱，只是为了方便理解而已。
</div>
<h2 id="设置蜂鸣器"><a class="markdownIt-Anchor" href="#设置蜂鸣器"></a> 设置蜂鸣器</h2>
<p>来设置蜂鸣器的引脚。我习惯使用 GP15（参考 <a href="#%E5%89%8D%E8%A8%80">先前的图片</a>，GP15 引脚已经和蜂鸣器连接好了）。你自然也可以根据自己的需要更改引脚：</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">buzzer = PWM(Pin(<span class="number">15</span>))</span><br><span class="line">buzzer.freq(<span class="number">50000</span>)</span><br><span class="line">buzzer.duty_u16(<span class="built_in">int</span>(<span class="number">65536</span> * <span class="number">0.2</span>))</span><br></pre></td></tr></tbody></table></figure>
<p>我们先创建了一个 PWM 对象，然后设置了 PWM 周期的频率为 50000Hz（不发出任何声音），最后设置了占空比为 20%。</p>
<center>————————</center>
<h1 id="编写代码"><a class="markdownIt-Anchor" href="#编写代码"></a> 编写代码</h1>
<h2 id="获取乐谱"><a class="markdownIt-Anchor" href="#获取乐谱"></a> 获取乐谱</h2>
<p>我选择用超级马里奥的 <a target="_blank" rel="noopener" href="https://onlinesequencer.net/25966">经典曲子</a> 来演示。Online Sequencer 的乐谱可以直接复制粘贴，如下：</p>
<figure class="highlight plaintext"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">Online Sequencer:616413:0 F#5 1 7;0 E6 1 7;2 F#5 1 7;2 E6 1 7;6 F#5 1 7;6 E6 1 7;10 F#5 1 7;10 C6 1 7;12 F#5 1 7;12 E6 1 7;16 G5 1 7;16 B5 1 7;16 G6 1 7;24 G5 1 7;32 E5 1 7;32 C6 1 7;38 C5 1 7;38 G5 1 7;44 G4 1 7;44 E5 1 7;50 C5 1 7;50 A5 1 7;54 D5 1 7;54 B5 1 7;58 C#5 1 7;58 A#5 1 7;60 C5 1 7;60 A5 1 7;64 C5 1 7;64 G5 1 7;66 G5 1 7;66 E6 1 7;69 B5 1 7;69 G6 1 7;72 C6 1 7;72 A6 1 7;76 A5 1 7;76 F6 1 7;78 B5 1 7;78 G6 1 7;82 A5 1 7;82 E6 1 7;86 E5 1 7;86 C6 1 7;88 F5 1 7;88 D6 1 7;90 D5 1 7;90 B5 1 7;96 E5 1 7;96 C6 1 7;102 C5 1 7;102 G5 1 7;108 G4 1 7;108 E5 1 7;114 C5 1 7;114 A5 1 7;118 D5 1 7;118 B5 1 7;122 C#5 1 7;122 A#5 1 7;124 C5 1 7;124 A5 1 7;128 C5 1 7;128 G5 1 7;130 G5 1 7;130 E6 1 7;133 B5 1 7;133 G6 1 7;136 C6 1 7;136 A6 1 7;140 A5 1 7;140 F6 1 7;142 B5 1 7;142 G6 1 7;146 A5 1 7;146 E6 1 7;150 E5 1 7;150 C6 1 7;152 F5 1 7;152 D6 1 7;154 D5 1 7;154 B5 1 7;164 E6 1 7;164 G6 1 7;166 D#6 1 7;166 F#6 1 7;168 D6 1 7;168 F6 1 7;170 B5 1 7;170 D#6 1 7;174 C6 1 7;174 E6 1 7;178 E5 1 7;178 G#5 1 7;180 F5 1 7;180 A5 1 7;182 G5 1 7;182 C6 1 7;186 C5 1 7;186 A5 1 7;188 E5 1 7;188 C6 1 7;190 F5 1 7;190 D6 1 7;196 E6 1 7;196 G6 1 7;198 D#6 1 7;198 F#6 1 7;200 D6 1 7;200 F6 1 7;202 B5 1 7;202 D#6 1 7;206 C6 1 7;206 E6 1 7;210 F6 1 7;210 G6 1 7;210 C7 1 7;214 F6 1 7;214 G6 1 7;214 C7 1 7;216 F6 1 7;216 G6 1 7;216 C7 1 7;228 E6 1 7;228 G6 1 7;230 D#6 1 7;230 F#6 1 7;232 D6 1 7;232 F6 1 7;234 B5 1 7;234 D#6 1 7;238 C6 1 7;238 E6 1 7;242 E5 1 7;242 G#5 1 7;244 F5 1 7;244 A5 1 7;246 G5 1 7;246 C6 1 7;250 C5 1 7;250 A5 1 7;252 E5 1 7;252 C6 1 7;254 F5 1 7;254 D6 1 7;260 G#5 1 7;260 D#6 1 7;266 F5 1 7;266 D6 1 7;272 C5 1 7;272 E5 1 7;272 C6 1 7;292 E6 1 7;292 G6 1 7;294 D#6 1 7;294 F#6 1 7;296 D6 1 7;296 F6 1 7;298 B5 1 7;298 D#6 1 7;302 C6 1 7;302 E6 1 7;306 E5 1 7;306 G#5 1 7;308 F5 1 7;308 A5 1 7;310 G5 1 7;310 C6 1 7;314 C5 1 7;314 A5 1 7;316 E5 1 7;316 C6 1 7;318 F5 1 7;318 D6 1 7;324 E6 1 7;324 G6 1 7;326 D#6 1 7;326 F#6 1 7;328 D6 1 7;328 F6 1 7;330 B5 1 7;330 D#6 1 7;334 C6 1 7;334 E6 1 7;338 F6 1 7;338 G6 1 7;338 C7 1 7;342 F6 1 7;342 G6 1 7;342 C7 1 7;344 F6 1 7;344 G6 1 7;344 C7 1 7;356 E6 1 7;356 G6 1 7;358 D#6 1 7;358 F#6 1 7;360 D6 1 7;360 F6 1 7;362 B5 1 7;362 D#6 1 7;366 C6 1 7;366 E6 1 7;370 E5 1 7;370 G#5 1 7;372 F5 1 7;372 A5 1 7;374 G5 1 7;374 C6 1 7;378 C5 1 7;378 A5 1 7;380 E5 1 7;380 C6 1 7;382 F5 1 7;382 D6 1 7;388 G#5 1 7;388 D#6 1 7;394 F5 1 7;394 D6 1 7;400 E5 1 7;400 C6 1 7;416 G#5 1 7;416 C6 1 7;418 G#5 1 7;418 C6 1 7;422 G#5 1 7;422 C6 1 7;426 G#5 1 7;426 C6 1 7;428 A#5 1 7;428 D6 1 7;432 G5 1 7;432 E6 1 7;434 E5 1 7;434 C6 1 7;438 E5 1 7;438 A5 1 7;440 C5 1 7;440 G5 1 7;448 G#5 1 7;448 C6 1 7;450 G#5 1 7;450 C6 1 7;454 G#5 1 7;454 C6 1 7;458 G#5 1 7;458 C6 1 7;460 A#5 1 7;460 D6 1 7;462 G5 1 7;462 E6 1 7;480 G#5 1 7;480 C6 1 7;482 G#5 1 7;482 C6 1 7;486 G#5 1 7;486 C6 1 7;490 G#5 1 7;490 C6 1 7;492 A#5 1 7;492 D6 1 7;496 G5 1 7;496 E6 1 7;498 E5 1 7;498 C6 1 7;502 E5 1 7;502 A5 1 7;504 C5 1 7;504 G5 1 7;512 F#5 1 7;512 E6 1 7;514 F#5 1 7;514 E6 1 7;518 F#5 1 7;518 E6 1 7;522 F#5 1 7;522 C6 1 7;524 F#5 1 7;524 E6 1 7;528 G5 1 7;528 B5 1 7;528 G6 1 7;536 G5 1 7;544 E5 1 7;544 C6 1 7;550 C5 1 7;550 G5 1 7;556 G4 1 7;556 E5 1 7;562 C5 1 7;562 A5 1 7;566 D5 1 7;566 B5 1 7;570 C#5 1 7;570 A#5 1 7;572 C5 1 7;572 A5 1 7;576 C5 1 7;576 G5 1 7;578 G5 1 7;578 E6 1 7;581 B5 1 7;581 G6 1 7;584 C6 1 7;584 A6 1 7;588 A5 1 7;588 F6 1 7;590 B5 1 7;590 G6 1 7;594 A5 1 7;594 E6 1 7;598 E5 1 7;598 C6 1 7;600 F5 1 7;600 D6 1 7;602 D5 1 7;602 B5 1 7;608 E5 1 7;608 C6 1 7;614 C5 1 7;614 G5 1 7;620 G4 1 7;620 E5 1 7;626 C5 1 7;626 A5 1 7;630 D5 1 7;630 B5 1 7;634 C#5 1 7;634 A#5 1 7;636 C5 1 7;636 A5 1 7;640 C5 1 7;640 G5 1 7;642 G5 1 7;642 E6 1 7;645 B5 1 7;645 G6 1 7;648 C6 1 7;648 A6 1 7;652 A5 1 7;652 F6 1 7;654 B5 1 7;654 G6 1 7;658 A5 1 7;658 E6 1 7;662 E5 1 7;662 C6 1 7;664 F5 1 7;664 D6 1 7;666 D5 1 7;666 B5 1 7;672 C6 1 7;672 E6 1 7;674 A5 1 7;674 C6 1 7;678 E5 1 7;678 G5 1 7;684 E5 1 7;684 G#5 1 7;688 F5 1 7;688 A5 1 7;690 C6 1 7;690 F6 1 7;694 C6 1 7;694 F6 1 7;696 F5 1 7;696 A5 1 7;704 G5 1 7;704 B5 1 7;706 F6 1 7;706 A6 1 7;709 F6 1 7;709 A6 1 7;712 F6 1 7;712 A6 1 7;714 E6 1 7;714 G6 1 7;717 D6 1 7;717 F6 1 7;720 C6 1 7;720 E6 1 7;722 A5 1 7;722 C6 1 7;726 F5 1 7;726 A5 1 7;728 E5 1 7;728 G5 1 7;736 C6 1 7;736 E6 1 7;738 A5 1 7;738 C6 1 7;742 E5 1 7;742 G5 1 7;748 E5 1 7;748 G#5 1 7;752 F5 1 7;752 A5 1 7;754 C6 1 7;754 F6 1 7;758 C6 1 7;758 F6 1 7;760 F5 1 7;760 A5 1 7;768 G5 1 7;768 B5 1 7;770 D6 1 7;770 F6 1 7;774 D6 1 7;774 F6 1 7;776 D6 1 7;776 F6 1 7;778 C6 1 7;778 E6 1 7;781 B5 1 7;781 D6 1 7;784 G5 1 7;784 C6 1 7;786 E5 1 7;790 E5 1 7;792 C5 1 7;800 C6 1 7;800 E6 1 7;802 A5 1 7;802 C6 1 7;806 E5 1 7;806 G5 1 7;812 E5 1 7;812 G#5 1 7;816 F5 1 7;816 A5 1 7;818 C6 1 7;818 F6 1 7;822 C6 1 7;822 F6 1 7;824 F5 1 7;824 A5 1 7;832 G5 1 7;832 B5 1 7;834 F6 1 7;834 A6 1 7;837 F6 1 7;837 A6 1 7;840 F6 1 7;840 A6 1 7;842 E6 1 7;842 G6 1 7;845 D6 1 7;845 F6 1 7;848 C6 1 7;848 E6 1 7;850 A5 1 7;850 C6 1 7;854 F5 1 7;854 A5 1 7;856 E5 1 7;856 G5 1 7;864 C6 1 7;864 E6 1 7;866 A5 1 7;866 C6 1 7;870 E5 1 7;870 G5 1 7;876 E5 1 7;876 G#5 1 7;880 F5 1 7;880 A5 1 7;882 C6 1 7;882 F6 1 7;886 C6 1 7;886 F6 1 7;888 F5 1 7;888 A5 1 7;896 G5 1 7;896 B5 1 7;898 D6 1 7;898 F6 1 7;902 D6 1 7;902 F6 1 7;904 D6 1 7;904 F6 1 7;906 C6 1 7;906 E6 1 7;909 B5 1 7;909 D6 1 7;912 G5 1 7;912 C6 1 7;914 E5 1 7;918 E5 1 7;920 C5 1 7;928 G#5 1 7;928 C6 1 7;930 G#5 1 7;930 C6 1 7;934 G#5 1 7;934 C6 1 7;938 G#5 1 7;938 C6 1 7;940 A#5 1 7;940 D6 1 7;944 G5 1 7;944 E6 1 7;946 E5 1 7;946 C6 1 7;950 E5 1 7;950 A5 1 7;952 C5 1 7;952 G5 1 7;960 G#5 1 7;960 C6 1 7;962 G#5 1 7;962 C6 1 7;966 G#5 1 7;966 C6 1 7;970 G#5 1 7;970 C6 1 7;972 A#5 1 7;972 D6 1 7;974 G5 1 7;974 E6 1 7;992 G#5 1 7;992 C6 1 7;994 G#5 1 7;994 C6 1 7;998 G#5 1 7;998 C6 1 7;1002 G#5 1 7;1002 C6 1 7;1004 A#5 1 7;1004 D6 1 7;1008 G5 1 7;1008 E6 1 7;1010 E5 1 7;1010 C6 1 7;1014 E5 1 7;1014 A5 1 7;1016 C5 1 7;1016 G5 1 7;1024 F#5 1 7;1024 E6 1 7;1026 F#5 1 7;1026 E6 1 7;1030 F#5 1 7;1030 E6 1 7;1034 F#5 1 7;1034 C6 1 7;1036 F#5 1 7;1036 E6 1 7;1040 G5 1 7;1040 B5 1 7;1040 G6 1 7;1048 G5 1 7;1056 C6 1 7;1056 E6 1 7;1058 A5 1 7;1058 C6 1 7;1062 E5 1 7;1062 G5 1 7;1068 E5 1 7;1068 G#5 1 7;1072 F5 1 7;1072 A5 1 7;1074 C6 1 7;1074 F6 1 7;1078 C6 1 7;1078 F6 1 7;1080 F5 1 7;1080 A5 1 7;1088 G5 1 7;1088 B5 1 7;1090 F6 1 7;1090 A6 1 7;1093 F6 1 7;1093 A6 1 7;1096 F6 1 7;1096 A6 1 7;1098 E6 1 7;1098 G6 1 7;1101 D6 1 7;1101 F6 1 7;1104 C6 1 7;1104 E6 1 7;1106 A5 1 7;1106 C6 1 7;1110 F5 1 7;1110 A5 1 7;1112 E5 1 7;1112 G5 1 7;1120 C6 1 7;1120 E6 1 7;1122 A5 1 7;1122 C6 1 7;1126 E5 1 7;1126 G5 1 7;1132 E5 1 7;1132 G#5 1 7;1136 F5 1 7;1136 A5 1 7;1138 C6 1 7;1138 F6 1 7;1142 C6 1 7;1142 F6 1 7;1144 F5 1 7;1144 A5 1 7;1152 G5 1 7;1152 B5 1 7;1154 D6 1 7;1154 F6 1 7;1158 D6 1 7;1158 F6 1 7;1160 D6 1 7;1160 F6 1 7;1162 C6 1 7;1162 E6 1 7;1165 B5 1 7;1165 D6 1 7;1168 G5 1 7;1168 C6 1 7;1170 E5 1 7;1174 E5 1 7;1176 C5 1 7;0 D4 1 7;2 D4 1 7;6 D4 1 7;10 D4 1 7;12 D4 1 7;24 G4 1 7;32 G4 1 7;38 E4 1 7;44 C4 1 7;50 F4 1 7;54 G4 1 7;58 F#4 1 7;60 F4 1 7;64 E4 1 7;66 C5 1 7;69 E5 1 7;72 F5 1 7;76 D5 1 7;78 E5 1 7;82 C5 1 7;86 A4 1 7;88 B4 1 7;90 G4 1 7;96 G4 1 7;102 E4 1 7;108 C4 1 7;114 F4 1 7;118 G4 1 7;122 F#4 1 7;124 F4 1 7;128 E4 1 7;130 C5 1 7;133 E5 1 7;136 F5 1 7;140 D5 1 7;142 E5 1 7;146 C5 1 7;150 A4 1 7;152 B4 1 7;154 G4 1 7;160 C4 1 7;166 G4 1 7;172 C5 1 7;176 F4 1 7;182 C5 1 7;184 C5 1 7;188 F4 1 7;192 C4 1 7;198 E4 1 7;204 G4 1 7;206 C5 1 7;220 G4 1 7;224 C4 1 7;230 G4 1 7;236 C5 1 7;240 F4 1 7;246 C5 1 7;248 C5 1 7;252 F4 1 7;256 C4 1 7;260 G#4 1 7;266 A#4 1 7;278 G4 1 7;280 G4 1 7;284 C4 1 7;288 C4 1 7;294 G4 1 7;300 C5 1 7;304 F4 1 7;310 C5 1 7;312 C5 1 7;316 F4 1 7;320 C4 1 7;326 E4 1 7;332 G4 1 7;334 C5 1 7;348 G4 1 7;352 C4 1 7;358 G4 1 7;364 C5 1 7;368 F4 1 7;374 C5 1 7;376 C5 1 7;380 F4 1 7;384 C4 1 7;388 G#4 1 7;394 A#4 1 7;400 C5 1 7;406 G4 1 7;408 G4 1 7;412 C4 1 7;416 G#3 1 7;422 D#4 1 7;428 G#4 1 7;432 G4 1 7;438 C4 1 7;444 G3 1 7;448 G#3 1 7;454 D#4 1 7;460 G#4 1 7;464 G4 1 7;470 C4 1 7;476 G3 1 7;480 G#3 1 7;486 D#4 1 7;492 G#4 1 7;496 G4 1 7;502 C4 1 7;508 G3 1 7;512 D4 1 7;514 D4 1 7;518 D4 1 7;522 D4 1 7;524 D4 1 7;536 G4 1 7;544 G4 1 7;550 E4 1 7;556 C4 1 7;562 F4 1 7;566 G4 1 7;570 F#4 1 7;572 F4 1 7;576 E4 1 7;578 C5 1 7;581 E5 1 7;584 F5 1 7;588 D5 1 7;590 E5 1 7;594 C5 1 7;598 A4 1 7;600 B4 1 7;602 G4 1 7;608 G4 1 7;614 E4 1 7;620 C4 1 7;626 F4 1 7;630 G4 1 7;634 F#4 1 7;636 F4 1 7;640 E4 1 7;642 C5 1 7;645 E5 1 7;648 F5 1 7;652 D5 1 7;654 E5 1 7;658 C5 1 7;662 A4 1 7;664 B4 1 7;666 G4 1 7;672 C4 1 7;678 F#4 1 7;680 G4 1 7;684 C5 1 7;688 F4 1 7;692 F4 1 7;696 C5 1 7;698 C5 1 7;700 F4 1 7;704 D4 1 7;710 F4 1 7;712 G4 1 7;716 B4 1 7;720 G4 1 7;724 G4 1 7;728 C5 1 7;730 C5 1 7;732 G4 1 7;736 C4 1 7;742 F#4 1 7;744 G4 1 7;748 C5 1 7;752 F4 1 7;756 F4 1 7;760 C5 1 7;762 C5 1 7;764 F4 1 7;768 G4 1 7;774 G4 1 7;776 G4 1 7;778 A4 1 7;781 B4 1 7;784 C5 1 7;788 G4 1 7;792 C4 1 7;800 C4 1 7;806 F#4 1 7;808 G4 1 7;812 C5 1 7;816 F4 1 7;820 F4 1 7;824 C5 1 7;826 C5 1 7;828 F4 1 7;832 D4 1 7;838 F4 1 7;840 G4 1 7;844 B4 1 7;848 G4 1 7;852 G4 1 7;856 C5 1 7;858 C5 1 7;860 G4 1 7;864 C4 1 7;870 F#4 1 7;872 G4 1 7;876 C5 1 7;880 F4 1 7;884 F4 1 7;888 C5 1 7;890 C5 1 7;892 F4 1 7;896 G4 1 7;902 G4 1 7;904 G4 1 7;906 A4 1 7;909 B4 1 7;912 C5 1 7;916 G4 1 7;920 C4 1 7;928 G#3 1 7;934 D#4 1 7;940 G#4 1 7;944 G4 1 7;950 C4 1 7;956 G3 1 7;960 G#3 1 7;966 D#4 1 7;972 G#4 1 7;976 G4 1 7;982 C4 1 7;988 G3 1 7;992 G#3 1 7;998 D#4 1 7;1004 G#4 1 7;1008 G4 1 7;1014 C4 1 7;1020 G3 1 7;1024 D4 1 7;1026 D4 1 7;1030 D4 1 7;1034 D4 1 7;1036 D4 1 7;1048 G4 1 7;1056 C4 1 7;1062 F#4 1 7;1064 G4 1 7;1068 C5 1 7;1072 F4 1 7;1076 F4 1 7;1080 C5 1 7;1082 C5 1 7;1084 F4 1 7;1088 D4 1 7;1094 F4 1 7;1096 G4 1 7;1100 B4 1 7;1104 G4 1 7;1108 G4 1 7;1112 C5 1 7;1114 C5 1 7;1116 G4 1 7;1120 C4 1 7;1126 F#4 1 7;1128 G4 1 7;1132 C5 1 7;1136 F4 1 7;1140 F4 1 7;1144 C5 1 7;1146 C5 1 7;1148 F4 1 7;1152 G4 1 7;1158 G4 1 7;1160 G4 1 7;1162 A4 1 7;1165 B4 1 7;1168 C5 1 7;1172 G4 1 7;1176 C4 1 7;:</span><br></pre></td></tr></tbody></table></figure>
<p>真是一大串呢~</p>
<p>稍微分析一下 Online Sequencer 乐谱的格式：</p>
<ol>
<li><code>Online Sequencer:616413:</code> 没有什么用，要被除掉</li>
<li><code>0 F#5 1 7;</code> 才是重点。<code>0</code> 是音符所处的时间位置，<code>F#5</code> 是音符的音高，<code>1</code> 是音符的持续时间，<code>7</code> 是播放用的乐器类型。Online Sequencer 乐谱中每个音符都是这样的格式，用分号隔开</li>
<li>还要注意最后有一个 <code>:</code>，这个也要除掉</li>
</ol>
<p>那么来编写一下将 Online Sequencer 乐谱转换为 Python 字典的代码吧。</p>
<p>先将 Online Sequencer 乐谱中需要被去除的部分去除掉，然后将乐谱中的音符部分根据 <code>;</code> 分割开来：</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">song = song_file.split(<span class="string">":"</span>)[<span class="number">2</span>]</span><br><span class="line">notes_list = song.split(<span class="string">";"</span>)[:-<span class="number">1</span>]</span><br></pre></td></tr></tbody></table></figure>
<p>接着把音符的时间位置提取出来，设为字典的键，音符的音高、持续时间和乐器类型设为字典的值：</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">notes_dict = {}</span><br><span class="line"><span class="keyword">for</span> note <span class="keyword">in</span> notes_list:</span><br><span class="line"> note_parts = note.split()</span><br><span class="line"> beat = <span class="built_in">float</span>(note_parts[<span class="number">0</span>])</span><br><span class="line"></span><br><span class="line"> <span class="comment"># 如果该时间位置是初次被添加到字典当中</span></span><br><span class="line"> <span class="keyword">if</span> beat <span class="keyword">not</span> <span class="keyword">in</span> notes_dict:</span><br><span class="line"> <span class="comment"># 添加该音符的信息到字典里</span></span><br><span class="line"> notes_dict[beat] = note_parts[<span class="number">1</span>:]</span><br><span class="line"> <span class="comment"># 如果该时间位置并不是第一次被添加到字典当中</span></span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> <span class="comment"># 如果该音符的音高比字典中已有的音符的音高更高</span></span><br><span class="line"> <span class="keyword">if</span> tones[note_parts[<span class="number">1</span>]] > tones[notes_dict[beat][<span class="number">0</span>]]:</span><br><span class="line"> <span class="comment"># 将该音符的信息覆盖到字典里</span></span><br><span class="line"> notes_dict[beat] = note_parts[<span class="number">1</span>:]</span><br></pre></td></tr></tbody></table></figure>
<p>由于是单个蜂鸣器播放，所以无法同时播放多个音符。当同个时间位置有多个音符时，我们只能选择音高最高的音符来播放。</p>
<p>至此，我们已经有了一个 Python 字典作为我们的乐谱。</p>
<h2 id="播放音频"><a class="markdownIt-Anchor" href="#播放音频"></a> 播放音频</h2>
<p>想要让蜂鸣器发出声音来很简单，代码如下：</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">buzzer.freq(tones[tone])</span><br><span class="line">time.sleep(duration)</span><br></pre></td></tr></tbody></table></figure>
<p><code>buzzer.freq()</code> 会设置蜂鸣器的频率，<code>time.sleep()</code> 会让程序暂停一段时间（在我们这个例子中，就是用来拉长音的）。</p>
<h2 id="播放乐谱"><a class="markdownIt-Anchor" href="#播放乐谱"></a> 播放乐谱</h2>
<p>结合上面两个部分，我们可以让字典中的音符一个一个地播放出来。但在这之前，还需要设置乐谱的播放速度。</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">bpm = <span class="number">199</span> <span class="comment"># 每分钟节拍数</span></span><br><span class="line">time_signature = [<span class="number">4</span>, <span class="number">4</span>] <span class="comment"># 拍号</span></span><br><span class="line">beat_duration = (<span class="number">60</span> / bpm) / time_signature[<span class="number">0</span>] <span class="comment"># 每拍的持续时间</span></span><br></pre></td></tr></tbody></table></figure>
<p>聊 <a href="#%E9%A2%98%E5%A4%96%E8%AF%9D">乐谱知识</a> 时说到过，拍号决定了每一小节有多少拍，什么音符的时值是一拍。从我们拿来马里奥曲子的 <a target="_blank" rel="noopener" href="https://onlinesequencer.net/25966">网站</a> 里能看到，马里奥曲子的 bpm 是 199、拍号是 4 / 4。</p>
<p>进行一小些计算，算出每一拍的持续时间为 <code>(60 / 199) / 4</code>。</p>
<p>继续编写播放乐谱的代码：</p>
<figure class="highlight python"><table><tbody><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 从第0拍开始播放</span></span><br><span class="line">current_beat = <span class="built_in">float</span>(<span class="number">0</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 播放到乐谱中最后一个音符的时间位置</span></span><br><span class="line"><span class="keyword">while</span> current_beat <= <span class="built_in">max</span>(notes_dict.keys()): </span><br><span class="line"> <span class="comment"># 取出当前时间位置的音符的持续时间（持续了多少拍），乘以每拍的持续时间，得到音符的持续时间（持续了多少秒）</span></span><br><span class="line"> note_duration = <span class="built_in">float</span>(notes_dict[current_beat][<span class="number">1</span>]) * beat_duration</span><br><span class="line"> </span><br><span class="line"> <span class="comment"># 如果当前时间位置有音符，就播放</span></span><br><span class="line"> <span class="keyword">if</span> current_beat <span class="keyword">in</span> notes_dict:</span><br><span class="line"> note_name = notes_dict[current_beat][<span class="number">0</span>]</span><br><span class="line"> </span><br><span class="line"> <span class="built_in">print</span>(<span class="string">"第"</span> + <span class="built_in">str</span>(current_beat) + <span class="string">"拍：播放音符 "</span> + note_name + <span class="string">" 中，持续时间为 "</span> + <span class="built_in">str</span>(note_duration) + <span class="string">" 秒。"</span>)</span><br><span class="line"> buzzer.freq(tones[note_name])</span><br><span class="line"> time.sleep(note_duration)</span><br><span class="line"></span><br><span class="line"> current_beat += <span class="built_in">float</span>(notes_dict[current_beat][<span class="number">1</span>])</span><br><span class="line"> buzzer.freq(<span class="number">50000</span>)</span><br><span class="line"> </span><br><span class="line"> <span class="comment"># 如果当前时间位置没有音符，就暂停</span></span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> <span class="built_in">print</span>(<span class="string">"第"</span> + <span class="built_in">str</span>(current_beat) + <span class="string">"拍：暂停，持续时间为"</span> + <span class="built_in">str</span>(note_duration) + <span class="string">" 秒。"</span>)</span><br><span class="line"> buzzer.freq(<span class="number">50000</span>)</span><br><span class="line"> time.sleep(beat_duration)</span><br><span class="line"> current_beat += <span class="number">1</span></span><br><span class="line"></span><br><span class="line"><span class="built_in">print</span>(<span class="string">"播放结束。"</span>)</span><br><span class="line">buzzer.freq(<span class="number">50000</span>)</span><br></pre></td></tr></tbody></table></figure>
<p>一个简单的播放乐谱的程序便完成了。</p>
<p>最终代码可以在 <a target="_blank" rel="noopener" href="https://github.com/Cytrogen/Music_Player_Pico">这个仓库</a> 里找到。</p>
<center>————————</center>
<h1 id="最终效果"><a class="markdownIt-Anchor" href="#最终效果"></a> 最终效果</h1>
<div class="danger">
该视频实际上并未是最终版本的效果，但没有差别多少。
</div>
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