Re: Unable (to (sends?)/recive from bulks endpoint.
Dan Streetman <ddstreet <at> ieee.org>
2007-09-13 13:45:59 GMT
If you still think the device isn't getting your data, I recommend
first tracing the data with Linux's built-in USB data monitor. If
that shows the data being transferred, I think your next step is
probably getting a USB bus trace machine to really verify that it's
being sent. Although, I will say that I think it's very unlikely that
Linux is dropping the data silently. If your data did not get to the
device, javax.usb should give you a error code.
I think it's much more likely that you may be either getting the
device's protocol wrong or simply leaving out command(s). Maybe you
should get a Windows (software) trace of *everything* going to/from
your device (not just your one specific command) and compare that to a
Linux monitor (software) trace of what you are sending to/getting from
your device. That is a lot cheaper than getting a hardware bus
If you do want to get a hardware bus tracer, I have used most of the
CATC (now owned by LeCroy) bus tracers. They are all fine tracers,
with relatively good analysis software. However they are *expensive*.
I've also used the USB 2.0 model of Ellisys bus tracer. It's a fine
tracer that will get the job done, but the analysis software is not at
all as good as the LeCroy software. But, it's a lot less expensive
than the LeCroy tracers.
If you're looking for a bus tracer that isn't multi-thousands of
dollars, I have seen one or two around that are "only" in the hundreds
of dollars, but at the time I think it was only USB 1.1 bus speeds,