USB to USB keyboard converter
=============================
2021/09/16


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.
2019/06 Rev.D   Update footprint with rounded pads
2019/09 Rev.E   Change QFP44 footprint and solder mask parameters
2020/02 Rev.F   Change Xtal footprint and paste clearance
2020/12 Rev.G   Remove LED




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




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