Err… My PROLiNK USB Keyboard is not supported by Samsung Galaxy S II USB OTG. Oh, I should use ‘was’ instead of ‘is’ because I managed to get it working on Samsung Galaxy S2 now. Thanks to XDA Developer, Td8f4. Without his patch, my USB keyboard is still detected as “High-power USB device connected ~ Unable to access this device. Connected device needs external power supply”. No worry if your USB keyboard is not working too, try below patch and it might works like mine…
51-android.rules