Re: [Discuss-gnuradio] USRP drivers vs UHD drivers in gnuradio-companion

[Marcus D. Leech]

> After successfully installed uhd and gnuradio from the next branch on 
> F13 i run a simple gnuradio-companion test with a flex 1800 as the 
> source and an FFT sink.
>
> It seems that when i use a uhd source my signal is ~ 80dB lower than 
> when using a USRP source. What is the explanation of this?
In "traditional", samples were in the -32K to +32K range, but under UHD, 
complex samples are in [-1, 1].  Just a scaling issue.


> Also, it used to be that I needed to be in the "usrp" group in order 
> to access the USRP.
> Now i deleted this group and i still have access to usrp (even when 
> the source is not a uhd one but a usrp source)!
> My understanding is that if i use the uhd device then i can do that
> (ie, don't need to be in the "usrp" group) but it seems to be 
> happening even with the usrp source.
> What am I missing?
Merely deleting the "usrp" group from group file doesn't do anything 
until you log-out/log-in again.

--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org