Let's make Linux OTG ports useful... http://www.chip-community.org/index.php/Chip:_USB_hid_on_libcomposite https://github.com/ckuethe/usbarmory/wiki/USB-Gadgets http://github.com/wismna/raspberry-pi/hackpi This setup has been tested on Raspberry Pi 0 and Allwinner A20 based board.