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?