20 Aug
2012
20 Aug
'12
9:51 a.m.
On 20 Aug 2012 at 8:41, Jochen Kunz wrote:
Also note: You can do USB 1.1 in software only. The
USBasp AVR
programmer does it. See: http://www.fischl.de/usbasp/ It works well
and is faster then my Atmel AVR Dragon. --
On 08/20/2012 12:01 AM, Chuck Guzis
wrote:
Looks like a nice rainy-day project. I've got a
bunch of Mega8's
sitting around waiting for a project. Also note the V-USB projects.
Even has USB in an 8-pin ATTiny AVR.
http://www.obdev.at/products/vusb/index.html The AT90USB162 is USB
2.0. --Chuck
Note that the bit-banging USB 1.1 is low speed (1.5 Mbps) only. There
are several limitations on low-speed devices. They may not use more
than two endpoints other than the control endpoint, and they may not use
payloads larger than 8 bytes in control or interrupt transfers.
The USB specification prohibits use of standard detachable cables with
low-speed devices, because they exceed the maximum allowable cable
length and capacitive load for low-speed (Sections 6.4.1 through 6.4.4
of the USB 1.1 and 2.0 specs). Normally low-speed devices use captive
cables. Vendor-unique detachable cables may be used; this means that
they can't use the normal USB B connector.