osmocom-sdr August 2016

osmocom-sdr@lists.osmocom.org

6 participants
7 discussions

RTL-SDR and RTL-TCP drivers
by Krzysztof Halasa 11 Jun '17

11 Jun '17

Hello, it's my first mail on this list, so please forgive me if I do something wrong. I'm about to post a couple of patches for RTL drivers: 1. RTL-SDR: convert _lut to float[] to reduce size by a factor of 256. The _lut is being indexed by I + Q (16 bits = 65536 entries), however both samples can be processed independently, resulting in 8-bit LUT. Saves a bit of RAM and CPU cache. lib/rtl/rtl_source_c.cc | 19 ++++++------------- lib/rtl/rtl_source_c.h | 4 ++-- 2 files changed, 8 insertions(+), 15 deletions(-) 2. RTL-TCP: Convert to single class model The existing RTL TCP driver is quite different from its brother RTL_SDR. It's much more complicated, uses gr::blocks::deinterleave and gr::blocks::float_to_complex, and generally doesn't work correctly (e.g. https://github.com/csete/gqrx/issues/99 Spectrum is mirrored when filter or demodulator changes (rtl_tcp) #99) I've converted the RTL TCP driver to the model used by RTL_SDR, simplifying it in the process, and fixing the GQRX issue. lib/rtl_tcp/CMakeLists.txt | 1 - lib/rtl_tcp/rtl_tcp_source_c.cc | 352 ++++++++++++++++++++++++++++++++-------- lib/rtl_tcp/rtl_tcp_source_c.h | 32 +++- lib/rtl_tcp/rtl_tcp_source_f.cc | 327 ------------------------------------- lib/rtl_tcp/rtl_tcp_source_f.h | 125 -------------- 5 files changed, 309 insertions(+), 528 deletions(-) I'm also thinking about merging the code common to RTL-SDR and RTL-TCP, but this it's done yet. Comments? -- Krzysztof Halasa

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Moving from trac to a single redmine
by Holger Freyther 25 Sep '16

25 Sep '16

Hi guys, I think some of us would like to move to redmine and start using public tickets more frequently. So in case we move there are some topics to be discussed and I would like to start with a couple of them right now. Tickets: Redmine has a global linear sequence of ticket numbers. If we move from many tracs to a single redmine we can either: * not import tickets * only import from one project * deal with changing ticket numbers In terms of installations the GMR trac is broken in regard to tickets, there are some for SDR that are probably not being fixed anytime soon, baseband might be relevant and OpenBSC is unlikely to be relevant. I don't think we have ever used ticket reference in OpenBSC commit messages so in terms of OpenBSC having changing ticket numbers would not be a big deal. E.g. we could add a custom field with the old trac number? Wiki: We have external references that should be redirected to the new place. Is there any way besides maintaining a list in the apache2/nginx configuration and making redirects as we find broken references? Can we proactively manage this? Is anybody willing to come up with a script and nginx configuration for doing this? kind regards holger

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Re: osmocom-sdr Digest, Vol 21, Issue 2
by CT2FZI IM58kr 24 Aug '16

24 Aug '16

unsubscribe Em 24/08/2016 22:55, <osmocom-sdr-request(a)lists.osmocom.org> escreveu: > Send osmocom-sdr mailing list submissions to > osmocom-sdr(a)lists.osmocom.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.osmocom.org/mailman/listinfo/osmocom-sdr > or, via email, send a message with subject or body 'help' to > osmocom-sdr-request(a)lists.osmocom.org > > You can reach the person managing the list at > osmocom-sdr-owner(a)lists.osmocom.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of osmocom-sdr digest..." > > > Today's Topics: > > 1. PATCH: Fixed arbitrary resampling in rtl_fm > (f.meyer-hermann(a)gsg-elektronik.de) > 2. Uccess! My first librtlsdr application (Neoklis Kyriazis) > 3. Re: Uccess! My first librtlsdr application (Lucas Teske) > 4. Fwd: Development of rtl-sdr driver (Piotr Krysik) > 5. RTL-SDR and RTL-TCP drivers (Krzysztof Halasa) > 6. [PATCH] RTL-SDR: convert _lut to float[] to reduce size by a > factor of 256 (Krzysztof Halasa) > 7. [PATCH] RTL-TCP: Convert to single class model (Krzysztof Halasa) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 25 Jul 2016 13:13:13 +0200 > From: f.meyer-hermann(a)gsg-elektronik.de > To: osmocom-sdr(a)lists.osmocom.org > Subject: PATCH: Fixed arbitrary resampling in rtl_fm > Message-ID: <20160725111313.GA15278(a)gsg-elektronik.de> > Content-Type: text/plain; charset=us-ascii > > As already on github, I fixed rtl_fm's arbitrary resampling by fixing the > output buffer length and allowing upsampling by copying the audio data > since > the algorithm cannot work in-place. > I have attached a patch, if you are interested to integrate it into the > official branch. > Regards, > > Ferdinand Meyer-Hermann > > > ------------------------------ > > Message: 2 > Date: Fri, 5 Aug 2016 05:09:49 +0000 (UTC) > From: Neoklis Kyriazis <nkcyham(a)yahoo.com> > To: "osmocom-sdr(a)lists.osmocom.org" <osmocom-sdr(a)lists.osmocom.org> > Subject: Uccess! My first librtlsdr application > Message-ID: > <1565657774.9528793.1470373789409.JavaMail.yahoo(a)mail.yahoo.com> > Content-Type: text/plain; charset=UTF-8 > > Hi > > > First, my thanks to everyone involved with the development and > release of librtlsdr. Well done. :-) > > I always wanted to try my hand building an SDR application and > so I installed the latest librtlsdr and started writing code > > to test the various functions in the librtlsdr library. Having > gotten familiar with this, I started work on modifying my old > Wx satellite APT image decoder app, xwxapt, to support an rtlsdr > receiver beside the linear VHF receiver it was written for. > > Its always difficult to extensively modify an existing app, but > in the end it all worked out well and xwxapt can now receive the > old APT format images from Wx sats with the rtl-sdr receiver. In > the process, I modified xwxapt to include controls for the rtl-sdr > unit, display an FFT-derived spectrum of the 2.4kHz sub-carrier > and a spectrum of the baseband O/P of the RTL2832 device. Images > are decoded in real time and displayed incrementally in xwxapt's > window. xwxapt is available under the GPL at: > > > http://www.5b4az.org/ in Weather Imaging->Image Decoders menu. > > -- > Best Regards > Neoklis - Ham Radio Call:5B4AZ > http://www.5b4az.org/ > > > ------------------------------ > > Message: 3 > Date: Fri, 5 Aug 2016 13:29:29 -0300 > From: Lucas Teske <lucas(a)teske.net.br> > To: osmocom-sdr(a)lists.osmocom.org > Subject: Re: Uccess! My first librtlsdr application > Message-ID: <fb16ab1f-4ff9-3ba5-04a0-5b1231fa72ef(a)teske.net.br> > Content-Type: text/plain; charset="utf-8" > > Nice Neoklis! > > > It looks good, I will give a try on the weekend :D > > > Btw, you should post the source-code at github, in this way it is easier > to submit patches and stuff. > > > Lucas > > Em 05/08/2016 02:09, Neoklis Kyriazis escreveu: > > Hi > > > > > > First, my thanks to everyone involved with the development and > > release of librtlsdr. Well done. :-) > > > > I always wanted to try my hand building an SDR application and > > so I installed the latest librtlsdr and started writing code > > > > to test the various functions in the librtlsdr library. Having > > gotten familiar with this, I started work on modifying my old > > Wx satellite APT image decoder app, xwxapt, to support an rtlsdr > > receiver beside the linear VHF receiver it was written for. > > > > Its always difficult to extensively modify an existing app, but > > in the end it all worked out well and xwxapt can now receive the > > old APT format images from Wx sats with the rtl-sdr receiver. In > > the process, I modified xwxapt to include controls for the rtl-sdr > > unit, display an FFT-derived spectrum of the 2.4kHz sub-carrier > > and a spectrum of the baseband O/P of the RTL2832 device. Images > > are decoded in real time and displayed incrementally in xwxapt's > > window. xwxapt is available under the GPL at: > > > > > > http://www.5b4az.org/ in Weather Imaging->Image Decoders menu. > > > > -- > > Best Regards > > Neoklis - Ham Radio Call:5B4AZ > > http://www.5b4az.org/ > > >

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Fwd: Development of rtl-sdr driver
by Piotr Krysik 08 Aug '16

08 Aug '16

Hi everyone, I've send the e-mail to the OpenBSC list before, but as I was informed by Harald this is the right place for such discussions. So I'm resending it here. The osmocom's version of rtl-sdr driver seems to be the main one. Osmocom's repository is used by distributions to build rtl-sdr packages and it is source of the code for compilation with use of GNU Radio's Pybombs. Is there someone in the Osmocom who is maintaining it? There were some important developments regarding this driver and it would be great to add these patches in the Osmocom's repo. For example one that interests me is turning off dithering so multiple dongles sharing the same clock generate the same LO frequency. Currently there is always little frequency offset that makes coherent of the receivers operation much harder. Such changes of course have to be done carefully so nothing gets broken in the process. In case of turning off dithering it results with worse tuning granularity, so for example turning it off could be made optional. -- Best Regards, Piotr Krysik

1 0

Uccess! My first librtlsdr application
by Neoklis Kyriazis 05 Aug '16

05 Aug '16

Hi First, my thanks to everyone involved with the development and release of librtlsdr. Well done. :-) I always wanted to try my hand building an SDR application and so I installed the latest librtlsdr and started writing code to test the various functions in the librtlsdr library. Having gotten familiar with this, I started work on modifying my old Wx satellite APT image decoder app, xwxapt, to support an rtlsdr receiver beside the linear VHF receiver it was written for. Its always difficult to extensively modify an existing app, but in the end it all worked out well and xwxapt can now receive the old APT format images from Wx sats with the rtl-sdr receiver. In the process, I modified xwxapt to include controls for the rtl-sdr unit, display an FFT-derived spectrum of the 2.4kHz sub-carrier and a spectrum of the baseband O/P of the RTL2832 device. Images are decoded in real time and displayed incrementally in xwxapt's window. xwxapt is available under the GPL at: http://www.5b4az.org/ in Weather Imaging->Image Decoders menu. -- Best Regards Neoklis - Ham Radio Call:5B4AZ http://www.5b4az.org/

2 1

[Help] first steps with sdrangelove
by loic.cloatre 02 Aug '16

02 Aug '16

Hello, I have installed all the thing and I get the main API: How to configure in order to see LoRa trafic? (if I click on aquisition, I get an error message "no sample source configured") Maybe a quickstart help exists? Thanks, Loïc

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Compiling rtlsdr for windows.
by Bill Gaylord 01 Aug '16

01 Aug '16

I know there is a precompiled binary but it is 2 years out of date. Anyone have any luck compiling it for 32 bit windows? (I need some functionality that was just recently added in)

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osmocom-sdr August 2016