I did find a simlar entry to this problem on the forum from last month but there was no usable solution for me unless I missed something. Also I have not found a way to allow me to change the USB permissions. Any advise will be a great help.
I have this issue on TWO DIFFERENT MACHINES. Here is what I did on each of them:
Completely fresh install of Ubuntu 12.04.4 LTS
apt-get libasound2-dev (because I need to use an 8 channel USB sound card with my GRC app)
install and configure pybombs (used all default settings)
./pybombs install gnuradio
each time I want to run gnuradio-companion I must first set the enviroment (a minor annoyance)
gnuradio_companion (GRC 3.7.5 GUI works fine)
However, I have no connection to the USRP B200
uhd_find_devices or uhd_usrp_probe returns the following:
USB open failed: insufficient permisssions.
See the application notes for your device.
No UHD Devices Found
running lsusb returns the following:
Bus 002 Device 006: ID 2500:0200
according the information in ~/target/lib/uhd/utils/uhd_usrp.rules, ID 2500:0200 is the B200 USRP