USB to USB keyboard converter
=============================
2014/12/21


Update
------
2015/02 Rev.A
2015/09 Rev.B   Fixed footprints, see TODO.txt.
2016/12 Rev.C   Fixed X'tal footprints and value of capacitors and resistor.



Resourses
---------
MAX3421E datasheet:
http://datasheets.maximintegrated.com/en/ds/MAX3421E.pdf

MAX3421E kicad library:
https://github.com/dominicgs/BeagleDancer/blob/master/hardware/lib/beagledancer.lib

Circuit@HOME USB Host Shield
http://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino

3.3V Teensy
https://www.pjrc.com/teensy/3volt.html



Hardware requirement
--------------------
Arduino Leonardo
    http://arduino.cc/en/Main/ArduinoBoardLeonardo 

Circuit@Home USB Host Shield 2.0
    https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino-assembled/

Buying Arduino Leonardo and USB Host Shield 2.0(from Circuit@home) will be the easiest way, you won't need even soldering iron.
Arduino's Shield will also work well but I think Sparkfun's needs to be modified.

    http://arduino.cc/en/Main/ArduinoUSBHostShield
    https://www.sparkfun.com/products/9947

Also Pro Micro 3.3V(not Mini) or Teensy with mini host shield will work with some fixes on signal/power routing.
    https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino-pro-mini
    https://www.sparkfun.com/products/12587
    https://www.pjrc.com/teensy/td_libs_USBHostShield.html



USB Host Shield 2.0
===================
Host Shield library:
    https://github.com/felis/USB_Host_Shield_2.0

Host Shield library debug output: USB_HOST_SERIAL
    https://github.com/felis/USB_Host_Shield_2.0/blob/master/settings.h