Re: [Discuss-gnuradio] Assertion Error when running gnuradio examples

[Thomas Schmid]

Hi Michael,

On 5/20/06, Michael Ford <address@hidden> wrote:
> Thomas,
>
> Yes, the firmware loaded correctly, as the frequency of the blinking
> lessened as I ran the oscilloscope example. As a matter of fact, the
> frequency never went back up again, even afte I closed the oscilloscope
> application. Is that a bad sign?

That is fine since you need to load the firmware only if you unplugged the USRP.

> As for thr configuration, I'm using a tranceiver daughterboard. One of the
> antenna inputs is marked TX/RX, the other is simply marked RX. I'm not at
> the office right now, but if you need more specific information, please let
> me know what you need and I'll run back up there and find out - it's only a
> 10 minute walk away.

Which daughterboards are you using? Oh, just saw it in the script. You
use the RFX2400 which accepts only the frequencies in the 2.4-2.5 GHz
(as was mentioned before). Thus, if you specify 101.4, it will not be
able to use that daughterboard and thus the assert failes.

> Finally, as I said before, I'll be implementing CSMA/CA, so I'll be spending
> alot of my time in the gmsk2 directory. Are these examples essential to the
> completion of my ultimate goal? Do these assertion errors pose a significant
> threat to my real plan?

No, the assertion errors are no problem if you specify the right
frequency ;) Go and have a look in the source files where the assert
fails. That might help you understand it better.

Cheers,

Thomas

> Thanks for your thoughtful/helpful reply,
> -Michael Ford-
>
>
> On 5/20/06, Thomas Schmid <address@hidden > wrote:
> > Hi Michael,
> >
> > GNURadio is under active development. Therefore, file names can change
> > and thus tutorials don't reflect the latest changes until they are
> > updated. The two file syou found, std_2rxhb_2tx.rbf and
> > std_4rx_0tx.rbf, are two different versions for the USRP firmware. the
> > first one has two rx and to tx paths, the second one has 4 rx and no
> > tx.
> >
> > When the oscilloscope run, did you see a change in the LED on your
> > USRP, i.e., did it first blink fast, and once the oscilloscope was
> > running it blinked slower? If, then everything is fine. If not, then
> > follow the installation instructions here:
> > http://www.comsec.com/wiki?UsrpInstall
> > except that I think we are at rev4 for the firmware now, instead of rev2.
> >
> > The exception you get is probably because you have the wrong
> > daughterboard in your USRP. What is the configuration you are using?
> >
> > Cheers,
> >
> > Thomas
> >
> > On 5/20/06, Michael Ford < address@hidden> wrote:
> > > Hello everyone,
> > >
> > > I'm a first time poster who's generally new to SDR as well as the
> gnuradio
> > > software. I've recently taken a course in communication networks and
> > > wireless networks, and this summer I'm working on using a few USRP
> boards to
> > > implement my own CSMA/CA protocol. However, before I get into the meat
> of
> > > that project, I've got to make sure that all my board setups are
> correct.
> > > Forgive me, this is going to be a mouthful.
> > >
> > > First things first - after visiting Dawei Shen's tutorials at the
> GNURadio
> > > website, I found that some of the instructions there were inconsistent
> with
> > > the files I got in the package - specifically tutorial number 4. I've
> > > installed the gnuradio package, and when reading the usrp tutorial, I'm
> told
> > > to make sure that I have a file called usrp_fpga_rev2.rbf in the
> > > /usr/local/share/usrp/rev2/ directory. (Which reminds me, if it helps,
> I'm
> > > running Ubuntu Dapper Drake) However, in the usrp package that I
> download
> > > from the gnuradio download page, I don't find that file, but instead I
> find
> > > two files called std_2rxhb_2tx.rbf and std_4rx_0tx.rbf. My first concern
> is,
> > > why don't I find the files I was told I'd find?
> > >
> > > My second concern still involves the 4th tutorial. I'm told to run
> > > usrp_oscope.py in the
> > > gr-build/gnuradio-examples/python/usrp/ directory,
> which
> > > I'm told will bring up an oscilloscope, which it does, so I'm assuming
> > > that's okay. Then I'm told to run wfm_rcv_gui.py [some fm frequency],
> which
> > > will let me hear fm signals. This is where my problem starts. First off,
> > > that file doesn't exist. So I try a file with a similar name -
> > > usrp_wfm_rcv_nogui.py -f 101.5. This gives me an assertion error, which
> > > looks like this:
> > >
> > > Using RX d'board A: Flex 2400 Rx
> > > >>> gr_fir_ccf: using SSE
> > > >>> gr_fir_fff: using SSE
> > > Traceback (most recent call last):
> > >    File "./usrp_wfm_rcv_nogui.py", line 149, in ?
> > >     fg = wfm_rx_graph()
> > >   File "./usrp_wfm_rcv_nogui.py", line 105, in __init__
> > >     if not(self.set_freq(options.freq)):
> > >   File "./usrp_wfm_rcv_nogui.py", line 125, in set_freq
> > >     r = self.u.tune(0, self.subdev, target_freq)
> > >   File
> > >
> "/usr/local/lib/python2.4/site-packages/gnuradio/usrp.py",
> > > line 184, in tune
> > >     return tune(self, chan, subdev, target_freq)
> > >   File
> > >
> "/usr/local/lib/python2.4/site-packages/gnuradio/usrp.py",
> > > line 122, in tune
> > >     ok, baseband_freq = subdev.set_freq(target_freq)
> > >   File
> > >
> "/usr/local/lib/python2.4/site-packages/gnuradio/db_flexrf.py",
> > > line 174, in set_freq
> > >     R, control, N, actual_freq = self._compute_regs(freq)
> > >   File
> > >
> "/usr/local/lib/python2.4/site-packages/gnuradio/db_flexrf.py",
> > > line 392, in _compute_regs
> > >     assert self.B_DIV >= self.A_DIV
> > > AssertionError
> > >
> > >
> > >
> > > My second concern is: why does the example file in the 4th tutorial not
> > > exist, and what might be causing this assertion error?
> > >
> > > -Michael Ford-
> > >
> > > _______________________________________________
> > > Discuss-gnuradio mailing list
> > > address@hidden
> > > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> > >
> > >
> > >
> >