So far as I am able to tell with my limited knowledge of limesdr and gnuradio, it seems like some kind of issue with the right settings to me.
The gr-limesdr provides a sink block that allows one to use an .ini file instead of the settings done via the block's settings. I will have access to the radio in a few days' time and am thinking i'll copy over the .ini file that was used in sdrangel and use the exact same one in gnuradio and see what happens. On Mon, Mar 22, 2021 at 8:22 AM Cinaed Simson <cinaed.sim...@gmail.com> wrote: > Hi Anish - yes, I removed the LImeSDR block from the flow graph. > > I inserted a throttle instead since I didn't have any front end hardware > available at the time. > > I do have a WBFM receiver using gnuradio running on a HackRF which works > great. > > But I'm using low pass filter taps in the complex rational resampler which > leads the WBFM receiver. > > -- CInaed > > On 3/20/21 7:52 PM, Anish Mangal wrote: > > Hi Cinaed, > > But this is without the actual LimeSDR sink block? Or with it? > > Because, I can produce a clean sinewave with a HackRF, but not the > LimeSDR. > > On Sun, Mar 21, 2021 at 1:07 AM Cinaed Simson <cinaed.sim...@gmail.com> > wrote: > >> Hi Anish - I think I may have found the problem. >> >> When the complex rational resampler is on the out put of the WBFM, it >> bothered me later that I couldn't see the top of the signal. >> >> The scale on QT GUI SINK was clipping the signal but not the >> computational noise. >> >> In the QT GUI SINK, if I set the Y-min to be -99 and Y-max to be 0, the >> signal looks perfect. >> >> And if the receiving RTL dongle has noise while listening, it may be a DC >> offset problem. >> >> -- Cinaed >> >> >> On 3/18/21 6:58 AM, Anish Mangal wrote: >> >> Here are two debug logs from LimeSuite GUI. In one, I load the settings >> that gnuradio does to the limesdr and see the debug log. The other is the >> settings file which the sdrangel writes. >> >> If I diff them, among other differences, this is what I see in the end of >> the sdrangel-debug-log >> DEBUG: Selected: VCOL >> DEBUG: csw 169; interval [166, 172] >> DEBUG: M=195, N=3, Fvco=1300.000 MHz >> >> And this is what I see in the gnuradio-debug-log >> DEBUG: Selected: VCOM >> DEBUG: csw 174; interval [171, 177] >> >> Now, I'm *very* new to this.. but could it mean that different VCOs are >> used in both cases, and in the case of gnuradio, it maybe has some issues >> to stabilize to some freq? >> >> On Thu, Mar 18, 2021 at 7:12 PM Christophe Seguinot < >> christophe.segui...@orange.fr> wrote: >> >>> Hi all >>> >>> There is something wrong in this simulation. >>> >>> Attached is a flowgraph with a selectable Lime SDR Source, and a RTL-SDR >>> dongle as receiver. I tested this with a Lime SDR Mini. >>> >>> - I was suspecting a Lime SDR issue, however this is not so clear. >>> - As Anish I also tested a const source. >>> - The flowgraph is running fluently and I dont' see any error >>> message about transmission to Lime SDR >>> >>> Conclusion of my simulations : >>> >>> - with a const source (=1) at Lime input : everything is OK, the >>> received signal is frequency shifted (normal) and the SNR is correct if >>> LimeSDR Gain is sufficient >>> - Using ratioanal resampler followed by WBFM Transmit Same reslt, >>> everything is OK >>> - First source+ WBFM + Rational resampler (this is a sample file >>> found on LimeSDR website >>> - the spectrum is not correct (look like a modulated signal >>> - the received signal magnitude is not constant >>> - >>> *BUT the send signal on the Time Sink look like correct. ( I.E =1+j0 as >>> for others sources, whitout any glicht) * >>> >>> How can we further investigate this? >>> >>> >>> On 18/03/2021 13:13, Anish Mangal wrote: >>> >>> And, if I try the attach gnuradio file, which is just a constant source >>> of value '1' going to the limesdr sink block, I actually see a sine-ish >>> wave without the glitchy behavior. >>> >>> On Thu, Mar 18, 2021 at 5:31 PM Anish Mangal <anis...@umich.edu> wrote: >>> >>>> I tried your grc and got the same result. >>>> >>>> See the waveform's envelope in this oscilloscope capture. Note the >>>> timebase. >>>> >>>> https://drive.google.com/file/d/1b7PnpmvFfdQTDIwALuOzb22AzeffzR2w/view?usp=sharing >>>> >>>> This isn't happening in SDRAngel. >>>> >>>> On Thu, Mar 18, 2021 at 3:49 AM Cinaed Simson <cinaed.sim...@gmail.com> >>>> wrote: >>>> >>>>> I moved the rational resampler block from the output side to the input >>>>> side of the WBFM. >>>>> >>>>> The output of WBFM block needs to match the input of your LimeSDR. >>>>> >>>>> I don't have the LimeSDR software installed so I couldn't look inside >>>>> the sink block. >>>>> >>>>> -- Cinaed >>>>> >>>>> P.S - yes, you can post GRC's on the mailing list - they're text >>>>> based. >>>>> >>>>> >>>>> On 3/17/21 4:14 AM, Anish Mangal wrote: >>>>> >>>>> I linked >>>>> <https://drive.google.com/file/d/1xQz1Kp_feAO1YrZRXXnMF25XEGgqVPSw/view?usp=sharing> >>>>> the grc file in the original email. Attaching it here as well. (Don't know >>>>> if the mailing list allows attachments) >>>>> >>>>> >>>>> >>>>> On Wed, Mar 17, 2021 at 1:40 PM Cinaed Simson <cinaed.sim...@gmail.com> >>>>> wrote: >>>>> >>>>>> >>>>>> Hi Anish - since this is a gnuradio mailing list, the starting point >>>>>> would be to post your GRC - which is an yaml or text file. >>>>>> >>>>>> -- Cinaed >>>>>> >>>>>> On 3/16/21 11:19 PM, Anish Mangal wrote: >>>>>> >>>>>> Hi! Any pointers to where I can start debugging this? >>>>>> >>>>>> Maybe run gnuradio-companion in debug mode? >>>>>> Do more simpler tests? >>>>>> Any other suggestions? >>>>>> >>>>>> I have a HackRF One and will try the exact same comparison there too >>>>>> ... SDRAngel & grc >>>>>> >>>>>> On Mon, Mar 15, 2021 at 7:32 PM Anish Mangal <anis...@umich.edu> >>>>>> wrote: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> To properly explain the issue I'm facing, I recorded a video showing >>>>>>> Oscilloscope waveforms. >>>>>>> >>>>>>> >>>>>>> https://drive.google.com/file/d/11anGShu-I3NhL9Jet6YAiyBprvwP4kDc/view?usp=sharing >>>>>>> >>>>>>> The gnuradio flowgraph is here: >>>>>>> >>>>>>> https://drive.google.com/file/d/1xQz1Kp_feAO1YrZRXXnMF25XEGgqVPSw/view?usp=sharing >>>>>>> >>>>>>> The various versions of the software/hardware involved are the >>>>>>> following. >>>>>>> >>>>>>> gnuradio-companion: 3.8.2.0 (Python 3.6.9) >>>>>>> gr-limesdr: branch gr-3.8 (last commit >>>>>>> 47511dd58de1695b70e1028366411bada85eb60f) >>>>>>> sdrangel: 4.12.1 >>>>>>> OS: Linux Mint 19.1 >>>>>>> CPU: Intel© Core™ i7-4900MQ CPU @ 2.80GHz × 4 >>>>>>> RAM: 16GB >>>>>>> H/w: Thinkpad T440p >>>>>>> >>>>>>> tl;dr >>>>>>> I'm trying a simple test to create a sinewave output from a WFM >>>>>>> modulator block. If there is no audio input, its WFM modulated signal >>>>>>> should be a simple sinewave. If I test this with SDRAngel, I see a >>>>>>> clean-ish actual sinewave in time domain on the oscilloscope. But if I >>>>>>> try >>>>>>> to do the same with gnuradio, it seems to produce a glitchy signal. >>>>>>> >>>>>>> Could I have any advice on what I might be doing wrong? >>>>>>> >>>>>>> Thanks, >>>>>>> Anish // VU2TVE >>>>>>> >>>>>> >>>>>> >>>>> >> >
