如何从耳机插孔获得电力? [英] How To Get Electric Power From Head Phone Jack?

问题描述

我的任务是，是否有人知道如何创建可以通过设备的耳机插孔发送电荷的Android应用，例如此视频

My quest is if anyone knows how to create an Android app that can send electric charge through the device's headphone jack, like in this video iPocket_LED. The video shows an app for iPhone that controls a LED plugged into the headphone jack.

我想知道如何访问设备以发送电信号.

I want to know how to access the device to send an electric signal.

对不起，我的英语不是我的语言，我希望有人能理解我

Sorry about my English, is not my language, I hope some one understand me

推荐答案

许多接受外部麦克风的消费类设备将提供插入电源".这是一个很小的电压，通常跨麦克风连接中的两个触点在1到5伏之间.

Many consumer devices which accept an external microphone will provide "plug-in power". This is a small voltage typically from 1 to 5 volts across two of the contacts in the microphone connection.

Apple和(大多数)Android设备也不例外.大多数使用带有以下引脚的4线TRRS连接:

Apple and (most) Android devices are no exception. Most use a 4-conductor TRRS connection with the following pin-out:

   TIP = left headphone out
  RING = right headphone out
  RING = ground
SLEEVE = mic in + plug-in power

在智能手机上，插入电源通常为2V左右，并且在麦克风(套管)导体上以+ 2V的形式提供.手机只有在检测到麦克风到位后才提供电源，这是通过测试麦克风与地面之间的电阻以查看其是否与麦克风的阻抗(例如200到5000欧姆的阻抗)一致来实现的，并且我听到了iphone可能非常麻烦，需要非常接近1600欧姆.

The plug-in power is usually around 2V on smartphones and is supplied as +2V on the microphone (sleeve) conductor. The phone will only supply it if it detects that a microphone is in place, which it does by testing the resistance across Mic to Ground to see if it's consistent with a microphone's impedance - something like 200 to 5000 ohms impedance, and I hear the iphones can be very fussy with this and need very close to 1600 ohms.

这意味着您可以从中获得最大功率，但看起来麦克风仍会很小-约为1.25毫安.有一些低功率微控制器或其他设备可以通过它供电.

This means the maximum power you could draw from this and still seem like a microphone would be pretty small - around 1.25 milliamps. There are some low powered microcontrollers or other devices you may be able to power with this.

请注意，插入式电源可能与幻像电源"具有相似的概念.用于专业音频设备，但这是一个不同且不兼容的标准.插入式电源"指的是:是什么导致智能手机耳机中的微型驻极体麦克风工作而无需自己的小电池.

Note that plug-in power may be a similar concept to "phantom power" as used in pro audio gear but it's a different and incompatible standard. "plug-in power" is what causes the tiny electret microphones in smartphone headsets to work without needing their own small battery.

关于如何从应用程序实际控制您所连接设备的控制，这正涉及到更加复杂的电子设备中.大概可以使用左右耳机输出线将信号发送到设备.

As for how to actually exert control over your attached device from an app, that's getting into much more complicated electronics. Presumably it is possible if you use the left and/or right headphone out lines to send signals to the device.

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