Re: [Discuss-gnuradio] Error when trying to run two python programs simultaneously

[Josh Blum]

On 03/23/2010 07:46 AM, drcabrejos wrote:
> Hi All,
>
> I have 2 (two) USRP1 and 2 (two) RFX2400 connected to each USRP1.
>
> What I want to do is to have communication between the devices and scan for
> the spectrum simultaneously.
>
> If running programs one by one, all works great.
> Running both at the same time, gives me an error saying that the USB port is
> already being used.
>
>
> Running: uses RFX2400 on port A
> /usr/share/gnuradio/examples/digital/tunnel.py --freq 2.422G
>
>
> Trying to start: uses RFX2400 on port B
> /usr/share/gnuradio/examples/usrp/usrp_spectrum_sense.py -R B 2.4095G
> 2.4625G

When you have multiple usrps, you need to differentiate them by using 
the "which" parameter:

tunnel.py has this option on the command line:
    -w WHICH, --which=WHICH
                        select USRP board [default=0]

try ./tunnel.py <your args here> -w1

spectrum_sense.py does not have this option, so it will have to be the 0 
by default or you will have to modify the script to pass which=<x> into 
the usrp contructor.

-josh