Android应用程序通过USB电缆的数据引脚发送信号

Question

I need to send a signal (basically some current) via my android phone through the usb data pin. Is there any way to do this. I have the basic knowledge of app development and am ready to create my own app. Any help would be appreciated :)

Answer 1

Unlike some older port designs (serial and parallel ports), USB does not provide for any arbitrary electrical control. Every pin serves a specific function in the USB protocol and cannot be arbitrarily set.

Some devices may have support for switching to an alternate non-USB mode, but nearly all such modes will similarly not allow for direct control.

If your Android phone supports USB host mode, then you could connect a USB-serial (RS232) adapter. This has two control pins that can be set arbitrarily, RTS and DTR, as well as the actual serial data line.