<div class="document"> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">* 1、项目功能介绍</h3> <hr class="horizontal-splitline normal-bold-2"><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">USB电流表，用于查看USB工作时的电流电压。<br>采用官方DCDC方案，BL9342转3.3V,实际测量范围6—24V,低于6V时，主控芯片无法工作。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">设计有LM2596稳压方案，但由于所占体积较大而放弃使用。</p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*2、项目属性</h3> <hr class="horizontal-splitline normal-bold-2"><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">参加嘉立创暑假训练营，复刻其中24V电流表案例。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">官方案例如下：</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><a href="/limengmeng12345/ji-chu-ying-usb-dian-ya-biao" target="_blank">【训练营官方案例】USB电流表 - 嘉立创EDA开源硬件平台 (oshwhub.com)</a></p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">*3、硬件部分</h3> <hr class="horizontal-splitline normal-bold-2"></div> <div class="document"><span style="font-size:16px;">1、降压方案</span></div> <div class="document"><span style="font-size:14px;">采用DCDC降压方案使电压稳定于3.3V为MCU供电。</span></div> <div class="document"><br><p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/ATZWFBlRBoRL7aXc88wrHTjSTxsRnbdxTzViRHUR.jpeg" alt="" width="700" height="330"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">LM2596-3.3参考方案（未使用）</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/euZdOFRWLrNLp0ZbDHNl6no1N3n0XAomZF9VGATa.jpeg" alt="" width="700" height="292"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><span style="font-size:16px;">2、烧录程序</span></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">采用外接方式下载程序。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/jcCJqfOVVQcr8pFuRQQ0vuu8zZIeORCZHsxqIu2A.jpeg" alt="" width="376" height="382"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">使用官方上位机通过串口进行程序下载。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/hocjPNDXSJ0AGjlTMi2Hm594MteMQvcd3lQjGPEh.jpeg" alt="" width="700" height="883"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><strong>注意事项</strong>，在通过串口下载程序时，首先要将BOOT位拉高电平，进入BOOT模式，串口工具的TX可能会给芯片倒灌电流，导致进入BOOT状态失败，可通过先上拉进入BOOT模式后再连接串口来解决。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <h3 class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">* 3、部分图片展示</h3> <hr class="horizontal-splitline normal-bold-2"><p style="line-height:1.8;">由于降压芯片无法工作于6V以下，且目前手中无大电压工作设备，所以通过外接3.3V的方式为MCU供电，以达到测量效果。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/hBZvdJq1zCa9Z1CVxfJASRJNosgli57gHZBY0cuG.jpeg" alt="" width="700" height="525"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/eU8gUHl1cVneJ6B5aGjJyIVlXcYKWJ76n397u1jG.jpeg" alt="" width="700" height="700"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/jggiBlzNvZDwoZRltxIGAdaglzoWCTPkMa8xYt60.jpeg" alt="" width="700" height="525"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> </div>