--- /dev/null
+USB to USB keyboard protocol converter
+======================================
+
+Hardware requirement
+--------------------
+Arduino Leonardo
+ http://arduino.cc/en/Main/ArduinoBoardLeonardo
+
+Circuit@Home USB Host Sheild 2.0
+ http://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino
+
+
+Build firmware
+--------------
+ $ git clone git://github.com/tmk/tmk_keyboard.git
+ $ cd tmk_keyboard
+ $ git checkout usb_hid
+ $ git submodule init
+ $ git submodule update
+
+and download LUFA and unzip under protocol/lufa and edit LUFA_PATH in protocol/lufa.mk. Then,
+
+ $ cd converter/usb_usb
+ $ make
+
+You will get usb_usb.hex if you are lucky.
+Program your Leonardo with avrdude(or easy-going Arduino IDE):
+
+ $ avrdude -patmega32u4 -cavr109 -PCOM17 -b57600 -Uflash:w:usb_usb.hex
+
+
+Limitation
+----------
+Only supports 'HID Boot protocol'.
+Not support keyboard LED yet.