- osmocom-sdr - lists.osmocom.org

R820T register map available
by Adam Nielsen 03 May '13

03 May '13

Hi all, One of the designers of the R820T tuner has recently been posting on the ultra-cheap-sdr group, and has kindly supplied a map of the R820T registers for private use only within the SDR community. He has asked that it not be posted on any website, but only be forwarded around privately. To that end, if anyone would like a copy of this spreadsheet and would be willing to likewise not publish it on the web, let me know off-list and I'll send it to you. There's not a huge amount in the way of explanations, but it lists all the registers and a very brief description of what they do. Cheers, Adam.

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Re: [Discuss-gnuradio] nVidia's Tegra 4 has SDR - the i500 LTE soft modem from Icera
by est 02 May '13

02 May '13

Hello group, What do you guys think of the nVidia Tegra 4's i500 SDR? http://www.engadget.com/2013/01/07/nvidia-i500-soft-modem/ http://www.nvidia.com/docs/IO/116757/NVIDIA_i500_whitepaper_FINALv3.pdf Is it hackable?

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Compiling on osx - solved...
by Alberto Albiol 01 May '13

01 May '13

Hello I have been fighting to compile the gr-osmosdr package in my osx These are the minor fixes I had to do: 1- Change in Cmakelists.txt: find_package(Boost COMPONENTS thread system), If thread and system is not included then there are linking problems. Although I see that this was removed recently... 2- cmake -DCMAKE_INSTALL_PREFIX=/opt/local (so it is installed together wit my ports intallation, this is really optional) 3- Before compiling I manually edit CmakeCache.txt, and change all the references of /usr/lib/python to /opt/local/lib/python. If not it links agains the system python instead of the ports's python! 4- Add this line in my .bashrc so python can find the package export PYTHONPATH="/opt/local/lib/python2.7/site-packages/" I am aware that this is not the most elegant way to solve the problem but is the only one that I was able to come up. Hope it helps Regards

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Re: rtl_fm scanning
by Colin Stagner 01 May '13

01 May '13

I am also having the rtl_fm scanning bug which was first reported in http://lists.gnumonks.org/pipermail/osmocom-sdr/2013-February/000485.html The scanning mode in rtl_fm hangs during the re-tuning process. This makes it impossible to use rtl_fm in scanning mode. I am using Ubuntu 12.10 with libusb 2:1.0.12-2, the latest git master version of rtl-sdr, and an Elonics E4000 (Realtek, RTL2838UHIDIR). Here are the steps to reproduce: 1. Find some frequency FREQ_NOISE that is not in use, and some frequency FREQ_SIGNAL which is in use constantly (i.e., like a commercial FM station). Find an appropriate squelch value SQUELCH which will stop FREQ_NOISE but pass FREQ_SIGNAL. 2. rtl_fm -f ${FREQ_NOISE} -l ${SQUELCH}. The program should not pass any audio, but it will exit cleanly with ^C. 3. rtl_fm -f ${FREQ_SIGNAL} -l ${SQUELCH}. The program should pass audio and exit cleanly with ^C 4. rtl_fm -f ${FREQ_SIGNAL} -f ${FREQ_NOISE} -l 0. The scan will pause on the first channel and pass audio. 5. rtl_fm -f ${FREQ_NOISE} -f ${FREQ_SIGNAL} -l ${SQUELCH}. The program will not output any audio, even though the first frequency is squelched out and the scanning function should skip immediately to the second frequency. Additionally, it will not exit if sent a SIGINT with ^C, and it must be killed with a SIGKILL. I've made a stack trace of this behavior. The program hangs very consistently at the same location each time: http://pastebin.com/wzE09MCi Thread 1 (the USB buffer reading thread) hangs while waiting for the data_write mutex lock in rtl_fm.c:642. I presume the thread has exhausted its supply of data and isn't getting any more. Thread 2 is slightly more interesting, because it hangs during the libusb system calls within the tuning function rtlsdr_set_center_freq() in librtlsdr.c:796. My guess is that it's making a blocking call that never returns. Can anyone else reproduce this bug?

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submitting patches
by Michael Davis 30 Apr '13

30 Apr '13

Hi All, Can anyone point me in the direction of a place I can go to submit patches? I fixed a bug in CMake for gnuradio-osmosdr that stopped the build on my system. Best, Mike

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Scanning with rtl_fm
by Alan Corey 28 Apr '13

28 Apr '13

I'm using rtl_fm in a scanning (nbfm) situation, and even with the antenna input disconnected and terminated, I get a burst of noise that sounds like a squelch tail maybe once each scan cycle. They're a little over 1 second apart. I've tried setting the squelch up to 10000 where I don't get signals anymore, but I still get the noise. I discovered that if you scan and have the output be a raw audio file, nothing gets recorded when nothing breaks squelch. This makes time-lapse recordings where all the pauses are taken out. Very nice, except for the noise bursts. I'm using: #!/bin/sh rtl_fm -N -S -l 132 -p 102 -f 854040000 -f 854240000 -f 854315000 -f 854415000 -f \ 854490000 -f 854540000 -f 855165000 -f 855240000 -f 858790000 -f 867350000 \ -f 867715000 /tmp/`date +"%Y-%m-%d_%H%M.raw"` and recorded overnight, but I mostly got noise bursts. Alan ----- Radio Astronomy - the ultimate DX

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gr-iqbal or gr-iqbalance?
by Wojciech Kazubski 28 Apr '13

28 Apr '13

Hello! This is a minor issue, but may lead to some misunderstanding (and seach failures) in future. The package to correct IQ imbalance is registered at http://cgit.osmocom.org as gr-iqbal but project name set in line 24 of toplevel CMakeList.txt is gr- iqbalance. Which name should be used while building packages, etc.? BTW: Is there any homepage for gr-iqbal/gr-iqbalance? Wojciech Kazubski

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OpenSourceDABplusSDRreceiver
by mrzfrn 26 Apr '13

26 Apr '13

"However, nobody has implemented a full and open DAB+ SDR receiver yet" Not true, look at http://www.sdr-j.tk/index.html Francesco

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[PATCH 1/1] add -S (synchronous) mode to rtl_fm
by Stuart Henderson 23 Apr '13

23 Apr '13

The enclosed diff adds a synchronous mode to rtl_fm. This helps OpenBSD (where libusb async isn't yet working). Signed-off-by: Stuart Henderson <stu(a)spacehopper.org> --- src/rtl_fm.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/src/rtl_fm.c b/src/rtl_fm.c index e8ebb77..a71e287 100644 --- a/src/rtl_fm.c +++ b/src/rtl_fm.c @@ -128,6 +128,7 @@ void usage(void) "\t[-E sets lower edge tuning (default: center)]\n" "\t[-N enables NBFM mode (default: on)]\n" "\t[-W enables WBFM mode (default: off)]\n" + "\t[-S force sync output (default: async)]\n" "\t (-N -s 170k -o 4 -A fast -r 32k -l 0 -D)\n" "\tfilename (a '-' dumps samples to stdout)\n" "\t (omitting the filename also uses stdout)\n\n" @@ -723,12 +724,14 @@ int main(int argc, char **argv) uint32_t dev_index = 0; int device_count; int ppm_error = 0; + int sync_mode = 0; char vendor[256], product[256], serial[256]; + fm_init(&fm); pthread_mutex_init(&data_ready, NULL); pthread_mutex_init(&data_write, NULL); - while ((opt = getopt(argc, argv, "d:f:g:s:b:l:o:t:r:p:EFA:NWMULRDC")) != -1) { + while ((opt = getopt(argc, argv, "d:f:g:s:b:l:o:t:r:p:EFA:NWMULRDSC")) != -1) { switch (opt) { case 'd': dev_index = atoi(optarg); @@ -815,6 +818,9 @@ int main(int argc, char **argv) case 'R': fm.mode_demod = &raw_demod; break; + case 'S': + sync_mode = 1; + break; default: usage(); break; @@ -921,9 +927,24 @@ int main(int argc, char **argv) fprintf(stderr, "WARNING: Failed to reset buffers.\n");} pthread_create(&demod_thread, NULL, demod_thread_fn, (void *)(&fm)); - rtlsdr_read_async(dev, rtlsdr_callback, (void *)(&fm), - DEFAULT_ASYNC_BUF_NUMBER, - lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH); + if (sync_mode) { + fprintf(stderr, "Reading samples in sync mode...\n"); + while (!do_exit) { + r = rtlsdr_read_sync(dev, &fm.buf, + lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH, + &fm.buf_len); + if (r < 0) { + fprintf(stderr, "WARNING: sync read failed.\n"); + break; + } + full_demod(&fm); + } + } else { + fprintf(stderr, "Reading samples in async mode...\n"); + rtlsdr_read_async(dev, rtlsdr_callback, (void *)(&fm), + DEFAULT_ASYNC_BUF_NUMBER, + lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH); + } if (do_exit) { fprintf(stderr, "\nUser cancel, exiting...\n");} -- 1.8.1.3

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rtl_test patch
by Nuno Gonçalves 21 Apr '13

21 Apr '13

Corrects bugs where: Cumulative PPM error is always "342" if execution stopped before first PPM_DURATION. PPM error alias to wrong values if over +-1045 (this happens quite a lot actually due to bug reported at [1]). Behavior changes: Cumulative PPM error value is now printed every PPM_DURATION so the user can check when it is settled. [1] http://lists.osmocom.org/pipermail/osmocom-sdr/2013-April/000584.html Thanks, Nuno Signed-off-by: Nuno Goncalves <nunojpg(a)gmail.com> diff --git a/src/rtl_test.c b/src/rtl_test.c index f5a56b8..c705e04 100644 --- a/src/rtl_test.c +++ b/src/rtl_test.c @@ -55,6 +55,8 @@ static int ppm_benchmark = 0; static int64_t ppm_count = 0L; static int64_t ppm_total = 0L; +static uint32_t samp_rate = DEFAULT_SAMPLE_RATE; + #ifndef _WIN32 static struct timespec ppm_start; static struct timespec ppm_recent; @@ -108,6 +110,7 @@ static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx) { uint32_t i, lost = 0; int64_t ns; + int real_rate; if (uninit) { bcnt = buf[0]; @@ -141,17 +144,23 @@ static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx) if (ppm_now.tv_sec - ppm_recent.tv_sec > PPM_DURATION) { ns = 1000000000L * (int64_t)(ppm_now.tv_sec - ppm_recent.tv_sec); ns += (int64_t)(ppm_now.tv_nsec - ppm_recent.tv_nsec); - printf("real sample rate: %i\n", + printf("real sample rate: %i", (int)((1000000000L * ppm_count / 2L) / ns)); - #ifndef __APPLE__ - clock_gettime(CLOCK_REALTIME, &ppm_recent); - #else - gettimeofday(&tv, NULL); - ppm_recent.tv_sec = tv.tv_sec; - ppm_recent.tv_nsec = tv.tv_usec*1000; - #endif + ppm_total += ppm_count / 2L; ppm_count = 0L; + + #ifndef _WIN32 + ns = 1000000000L * (int64_t)(ppm_now.tv_sec - ppm_start.tv_sec); + ns += (int64_t)(ppm_now.tv_nsec - ppm_start.tv_nsec); + real_rate = (int)(ppm_total * 1000000000L / ns); + printf(" cumulative PPM error: %.1f\n", + (1000000.0 * (real_rate - (int)samp_rate)) / samp_rate); + #else + printf("\n"); + #endif + + ppm_recent = ppm_now; } #endif } @@ -213,13 +222,10 @@ int main(int argc, char **argv) int sync_mode = 0; uint8_t *buffer; uint32_t dev_index = 0; - uint32_t samp_rate = DEFAULT_SAMPLE_RATE; uint32_t out_block_size = DEFAULT_BUF_LENGTH; int device_count; int count; int gains[100]; - int real_rate; - int64_t ns; while ((opt = getopt(argc, argv, "d:s:b:tpS::")) != -1) { switch (opt) { @@ -365,15 +371,6 @@ int main(int argc, char **argv) if (do_exit) { fprintf(stderr, "\nUser cancel, exiting...\n"); - if (ppm_benchmark) { -#ifndef _WIN32 - ns = 1000000000L * (int64_t)(ppm_recent.tv_sec - ppm_start.tv_sec); - ns += (int64_t)(ppm_recent.tv_nsec - ppm_start.tv_nsec); - real_rate = (int)(ppm_total * 1000000000L / ns); - printf("Cumulative PPM error: %i\n", - (int)round((double)(1000000 * (real_rate - (int)samp_rate)) / (double)samp_rate)); -#endif - } } else fprintf(stderr, "\nLibrary error %d, exiting...\n", r);

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