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androidusbusb-otg

Android USB OTG: programmatically turn off power to the port

Suppose I have a USB-powered LED lamp connected through a USB OTG adapter to a Toshiba Excite 10 tablet running Android 4.0.3, which provides the power.

I want to programmatically turn the USB OTG host port's power pins on and off from an app. (Ideally without root, but I'll take what I can get). Any ideas?

Solution

  • You must have write permission on /sys directory. Rooting makes the process very easy. Just root your device and issue the right echo command to toggle kernel status bits like : 

    String[] command = { "/system/bin/sh", "-c", "echo xxx > /sys/bus/usb/devices/usb3/power/level", };
Runtime.getRuntime().exec(command);

    Another way is to use libusb, dig the library for the function that cuts the power off. You can use android.hardware.usb.UsbManager to request proper permission for libusb.