18 Jan
2012
18 Jan
'12
7:28 p.m.
On 1/18/2012 5:34 PM, Chuck Guzis wrote:
The USB keyboard and mice are special HID devices and
not at all like
most other USB devices as I noted. As a counter-example, I suspect
you'll have a lot of trouble talking to a USB flash drive with an ATMega8.
I
think, in the midst of trimming the post, we've messed with the OP's
goal, USB KB to KB matrix. For that purpose, a "pseudo" USB Host
implementation that can handle HID would suffice, though it might be
more trouble than simply obtaining a true OTG-capable uC.
One of my most important design goals is the ability to support a USB
flash drive. It sounds silly to do so on a KB interface, but I have
found "field-upgrades" to be an essential hobbyist project criteria, as
it allows incomplete firmware to be enhanced and bugs fixed without
requiring all customers own a programmer and remove the device from the
circuit. It makes hobbyist projects infinitely more pleasurable to
produce, as you can feel significantly less guilty if a bug is found
after production. For this feature, alas, a pseudo-USB host
functionality would probably not be enough.
For the DIYer, though, it might be enough to use LUFA and it's at90USB
HID host support.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com