[sane-devel] Libusb - reads and writes?

m. allan noah anoah at pfeiffer.edu
Fri Dec 8 16:20:00 CET 2006

On Thu, 7 Dec 2006, René Kjellerup wrote:

> So the primary question is, which endpoint does
> one write to, and which does one read from?

the in/out identifiers are written from the perspective of the host, not 
the device. so you read in and write out. just as a check, the IN endpoint 
will have its high bit set (0x80).

it is not unusual to get timeout errors and other weirdness on your first 
command to the device, some fujitsu scanners require you to call TEST UNIT 
READY several times with a really short timeout and ignore the errors 
before they will play.


"so don't tell us it can't be done, putting down what you don't know.
money isn't our god, integrity will free our souls" - Max Cavalera

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