Saturday, 31 January 2015

USB OTG host mode API issues with some Android devices

It has been reported recently that some devices doesn't support USB API correctly, despite having Android version > 3.1 (the first release with USB OTG host mode API available to application layer).

Basically, the non-functioning devices can be divided into two groups:

a) Hardware USB host mode not implemented.

A good example is LG Swift G (or related) mobile handheld, a rumour says that +5V DC supply voltage is not available, a result of hardware cost-cutting. Obviously there's nothing that could be done to enable USB host mode on those devices

b) Hardware USB compatible with host mode, Android version >=3.1, pendrive or mouse works fine, yet no USB devices are visible form the application layer.

This mostly is true when it comes to no-name devices (tablets), it looks as if manufacturers were in a big rush to release a product and forgot to properly configure Android OS.

Some devices can be fixed, a solution is to modify/copy a file in the /system/etc/permissions.

One must have root access to able to remount and modify those files.

See the thread:

Quotation from the above link:

"To enable USB host API support you should add a file named
and containing the following lines:

<permissions> <feature name=""/> </permissions>

into folder


in that folder find file named

handheld_core_hardware.xml or tablet_core_hardware.xml

and add

<feature name="" />

into <permissions> section.

Reboot your device. Usb host api should work."

Some tablets have root by default, it's only necessary to switch into superuser, this can be done with Total Commander

Or by using "adb" command-line utility:

adb shell 
 mount -o rw,remount -t ext4 /system

Be careful with system files/directories it's very easy to brick your device. First make sure you are able to restore the original OS rom image (in case of...) before trying the above hack.


  1. i have this file but not working!

  2. I dont have this file what can i do or how can i add it

  3. I dont have this file what can i do or how can i add it

  4. hi,
    im trying to connect an usb obd elm327 interface, it is possible?