USRP usb cable question


#1

Hi

My earlier usb problem seems to be related to the cable I was using. I
tried my home printer’s cable and it began to work. I could load the
firmware and the standard tx and rx programs worked perfectly. I tried
out the usrp_fft.py script. It worked initially and then I got a stream
of usb protocol errors which caused the script to crash. When I tried to
reconnect the board I saw that I was back to square one with the USRP
failing to connect. I also noticed that even though the script crashed
and the was no longer running, the USRP was still drawing just over 1A.

My question is: Is there any way or situation where communication
between the USRP and the pc could cause the usb cable to be damaged? I
haven’t tried another cable yet, because I’m uncertain if the same thing
would happen again.

I did rmmod ehci_hcd and connected the USRP to the same port. I could
succesfully connect and load firmware. I assumes this means that the
USB2 pci card is working and that the cable can still do USB1.1
connections and that the USRP is fine as well. Is there a very specific
kind of USB2 cable I should be using? A shielded type or something?

Regards

Lance


#2

On Thu, Apr 06, 2006 at 05:41:00AM -0700, seph 004 wrote:

Hi

My earlier usb problem seems to be related to the cable I was
using. I tried my home printer’s cable and it began to work.

Throw the bad one away – I’m not kidding, and buy a cable certified
for USB 2.0. At least around here, they’re only a few dollars.

I could load the firmware and the standard tx and rx programs worked
perfectly. I tried out the usrp_fft.py script. It worked initially
and then I got a stream of usb protocol errors which caused the
script to crash. When I tried to reconnect the board I saw that I
was back to square one with the USRP failing to connect. I also
noticed that even though the script crashed and the was no longer
running, the USRP was still drawing just over 1A.

Which distribution and kernel are you using?

From watching the linux usb developers list, there seems to have been
some regressions with 2.6.15. If you’re using that particular kernel,
move up or back.

My question is: Is there any way or situation where communication
between the USRP and the pc could cause the usb cable to be
damaged? I haven’t tried another cable yet, because I’m uncertain
if the same thing would happen again.

No, the USRP can’t damage the cable.

I did rmmod ehci_hcd and connected the USRP to the same port. I
could succesfully connect and load firmware. I assumes this means
that the USB2 pci card is working and that the cable can still do
USB1.1 connections and that the USRP is fine as well. Is there a
very specific kind of USB2 cable I should be using? A shielded type
or something?

Any USB 2.0 cable “USB-A Male to USB-B Male” will work. You don’t
need the gold plated “Monster Cable”. Not sure where you live; pretty
much any computer related store will carry them. Fry’s, Best Buy, …
I’m sure that Office Max and Office Depot carry them too, but
they’ll be more expensive there.

Jameco’s got them for $1.89 if you want to mail order.

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=229737

Eric