Re: [Discuss-gnuradio] Re: USRP2 current svn code not working. Is the svn code still in flux?

[Eric Blossom]

On Sun, Oct 26, 2008 at 10:47:34PM +0100, Martin DvH wrote:
> 
> On Sun, 2008-10-26 at 14:03 -0700, Johnathan Corgan wrote:
> > On Sun, 2008-10-26 at 21:49 +0100, Martin DvH wrote:
> > 
> > > The new fpga image in combination with the latest svn code also makes it 
> > > possible to set the gain from the gui of usrp2_fft.py without crashing 
> > > the app.
> > > (And the gain actually changes as can be seen by the change in signal
> > > level)
> > > 
> > > Trying to set the frequency this way is not fixed. This still hangs the
> > > whole app.
> > 
> > I've updated usrp2_fft.py on the trunk to use the latest gr-usrp2.  It
> > is working normally now with setting the USRP2 parameters via the
> > command line, however, as you note, changing frequency doesn't work.
> > This has been isolated to some problem in either libusrp2 or in the
> > USRP2 firmware.  Eric and I are working on this.
> > 
> > Other commands that operate in "batch" mode, where you set the USRP2
> > parameters from the command line, are working normally now as well.
> > 
> When you set the decimation above 19 then you CAN set gain in the GUI.
> With decimation below 19, setting gain in the GUI hangs the app.
> 
> Setting the freq only works from commandline.

There are two problems I've identified:  One has to do with printfs
being done by the firmware.  Taking care of that fixes allows the gain
setting to work.  The other problem I'm still working on, but I think
it's that setting the freq is taking too long without servicing the
ethernet.  This results in an overrun, which stops the streaming data.


> The gainrange for "TVRX rev 3" comes out as 0 , 0
> This triggers a python error min <max ==False and the gain slider cannot
> be used.
> 
> I saw you have a workaround for the gainrange for TVRX, probably this
> should also apply for TVRX rev 2 and TVRX rev 3.
> (Or there is something else wrong in the backend code)

> Following patch adds the workaround for alls TVRXs.

Thanks.

This needs to be fixed in the firmware table that describes the
tvrx d'boards, and the python code needs fixing so that it doesn't die on
the 0, 0 case, since that is the right answer for the Basic Tx and
Rx.  (There's no PGA on the USRP2.)

Eric