Is it possible for an Android 4 phone with only a standard micro-USB port (not OTG), to be provided with a USB host port through an adapter using the Android accessory protocol? Do such adapters exist?
The adapter would need power and 2 USB ports. One USB port would act as a host and plug any USB device (for example a keyboard), the other would act as an 'Android accessory' and plug into the phone. Android should be able to use the device as if it were plugged in directly to a host port (on a tablet).
It would be really great if the adapter was also powered by micro-USB, and that it could pass-through data to a computer host (Storage, tether, ADB, etc.).
Is all/any of this possible? Do such adapters exist? If not, how would I make one?