Android USB host and hidden devices

Question

I am developing an Android application in which I have to communicate to an USB device. I tried to use standart google API in my app, but list of devices is allways empty.

Same things if i use USB device info with google api. List of devices searched by google api is empty,

lsusb gives following results:

Bus 001 Device 001: ID 1d6b:0001 Bus 002 Device 001: ID 1d6b:0002 Bus 003 Device 001: ID 1d6b:0001 Bus 002 Device 002: ID 2226:0014 

my device is 2226:0014

log of eclipse:

I/USB3G(92): event { 'add', '/devices/platform/sw-ehci.1/usb2/2-1', 'usb', '', 189, 133 } I/USB3G(92): path : '/sys/devices/platform/sw-ehci.1/usb2/2-1' I/USB3G(92): VID :size 5,vid_path '/sys/devices/platform/sw-ehci.1/usb2/2-1/idVendor',VID  '2226 I/USB3G(92): '. I/USB3G(92): PID :size 5,Pid_path '/sys/devices/platform/sw-ehci.1/usb2/2-1/idProduct',PID  '0014 I/USB3G(92): '. I/USB3G(92): cmd=/system/etc/usb_modeswitch.sh /system/etc/usb_modeswitch.d/2226_0014 &, I/USB3G(92): excute ret : 0,err:No such file or directory 

If i plug in devices like rs232 adapters, bluetooth dongle, nothing happens,and there is no any result from API and lsusb.

Prtocol of a device is based on ezusb library. Android v.: 4.0.3 kernel v.: 3.0.8 firmware build: crane_evb-eng 4.0.3 IMLK74k 20120330

Is there are any way to access hidden USB devices via API, or should i implement support of this device by writing driver and patching it into the firmware?

UPDATE: even if i create info file in *system/etc/usb_modeswitch.d/* with name 2226_0014 containing

DefaultVendor= 0x2226 DefaultProduct=0x0014 TargetVendor=  0x2226 TargetProductList="0014" MessageEndpoint="0x00" NeedResponse=1 CheckSuccess=20 

i get the same error: "No such file or directory"

Answer 1

To enable USB host API support you should add a file named
android.hardware.usb.host.xml and containing the following lines:

<permissions>  <feature name="android.hardware.usb.host"/> </permissions> 

into folder

/system/etc/permissions 

in that folder find file named

handheld_core_hardware.xml or tablet_core_hardware.xml  

and add

<feature name="android.hardware.usb.host" /> 

into <permissions> section.

Reboot your device. Usb host api should work.

Tested on CUBE U30GT with android 4.

Answer 2

Excellent! This worked on my Envizen V700NA running Android 4.0.4.

Minor Typo: <feature name="android.hardware.usb.host">

Should be: <feature name="android.hardware.usb.host"/>

Procedure:

1. adb pull /system/etc/permissions/tablet_core_hardware.xml
2. Update that file and create android.hardware.usb.host.xml as specified by Greg-q.
3. adb push android.hardware.usb.host.xml /system/etc/permissions
4. adb push tablet_core_hardware.xml /system/etc/permissions
5. Reboot.