osmocom-sdr

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910 discussions

osmo-fl2k
by Riccardo Rossi 25 Apr '18

25 Apr '18

Hi, i want to ask you which screen do you use in the picture in the website and also if this https://www.amazon.it/dp/B019DUI17Q/ref=cm_sw_r_wa_api_i_on53AbMBGRVYA has the correct chip Thank you Riccardo Rossi

2 1

fl2k RGB buffer format
by Abhishek Goyal 25 Apr '18

25 Apr '18

I am trying to understand the layout of the RGB buffers sent to the fl2k over USB. From lines 755-820 in libosmo-fl2k.c I can see the RGB buffers are "serialized" in this order: g1,r1,b2,g2,b0,g0,r0,b1,b4,g4,r4,b5,r2,b3,g3,r3,r6,b7,g7,r7,g5,r5,b6,g6 (where r0 is the red component of first pixel, b3 is the blue component of fourth pixel, etc) What is this layout? Why does the chip expect the pixels to be sent in this order?

2 2

Bug: gr-osmoscom for USRP B210 have this weird center frequency signal while gr-UHD don't
by Ignatius Rivaldi 24 Apr '18

24 Apr '18

Hi, At first I reported this bug at Gqrx mailing list: https://groups.google.com/forum/#!topic/gqrx/pVea3JObMLw , then Csete mentioned that Gqrx uses gr-osmosdr source, while I'm using gr-uhd source. Then I tried it again using osmocom source, then that weird center frequency noise appears again. I've attached several screenshots and GRC flowchart that I used to reproduce this bug (it uses gr-fosphor). Maedhros_008.png is the screenshot of gr-fosphor displaying the correct UHD: USRP source, with all of FM broadcast radio visible, while Maedhros_011.png is the gr-fosphor showing the output of osmocom source, with this big ~2MHz spike at center frequency, and all of those FM broadcast radio are not visible. I'm using Arch Linux with gnuradio, gr-fosphor, and gr-osmosdr compiled from source using makepkg/pkgbuild system, and libuhd 3.10.2.0-3

2 1

Gnuradio >= 3.7.12.0 breaks gr-fosphor
by Ignatius Rivaldi 19 Apr '18

19 Apr '18

Hi, A QT API change in Gnuradio 3.17.12.0 : https://github.com/gnuradio/gnuradio/pull/1418 breaks modules that relies on QT windowing system, resulting in Template error on generated python file, resulting in this error when I try to run the generated python file: Executing: /usr/sbin/python2 -u /home/feanor/Development/SDR/top_block.py File "/home/feanor/Development/SDR/top_block.py", line 69 self.fosphor_qt_sink_c_2 = Template error: #set $win = 'self._%s_win'%$id ^ SyntaxError: invalid syntax >>> Done (return code 1) This also affects other modules that relies on QT: gr-inspector: https://github.com/gnuradio/gr-inspector/issues/2 Following the fix in this pull request for gr-inspector: https://github.com/gnuradio/gr-inspector/pull/21/commits/9d00bb83c155c84ee8… by changing a line: 15c15 < $(gui_hint()($win))</make> --- > $(gui_hint() % $win)</make> fixes the problem for gr-fosphor and make the flowgraph runnable again

3 2

windows GNU Radio error 12 Fatal failed to find rtlsdr device
by Jose Mihotek 17 Apr '18

17 Apr '18

All, I installed GNU Radio for windows on my machine running Windows 10.when I try to run GRC it comes back with: <<< Welcome to GNU Radio Companion 3.7.11.1 >>> Block paths: C:\Program Files\GNURadio-3.7\share\gnuradio\grc\blocks Loading: "C:\Users\JoseM\Documents\GNU\test w grc.grc">>> Done Generating: 'C:\\Users\\JoseM\\Documents\\GNU\\top_block.py' Executing: C:\Program Files\GNURadio-3.7\gr-python27\python.exe -u C:\Users\JoseM\Documents\GNU\top_block.py Win32; Microsoft Visual C++ version 14.0; Boost_106000; UHD_003.010.001.001-0-unknown gr-osmosdr c653754d (0.1.5git) gnuradio 3.7.11.1built-in source types: file osmosdr fcd rtl rtl_tcp uhd hackrf bladerf airspy redpitaya Using device #0 Generic RTL2832U OEMusb_open error -12 FATAL: Failed to open rtlsdr device. Trying to fill up 1 missing channel(s) with null source(s).This is being done to prevent the application from crashingdue to gnuradio bug #528. Anybody have any idea how to fix this ?Thanks, Jose

1 0

Re: Meaning of rtl_fm output values
by Müller, Marcus (CEL) 15 Mar '18

15 Mar '18

Hi Theodric, no, these values that appear on stdout are already audio samples (PCM to be specific). That is the "job" of rtl_fm: It takes the complex time-domain baseband samples from the hardware, detects FM (which implies detecting a frequency deviation) and convert that to audio amplitude values. The `aplay` command barely takes these samples and hands them over to the sound card (after resampling to fit possible sampling rates, I guess, as 120 kHz isn't something that sound systems usually operate at). The `rtl_fm` command takes a couple of parameters. In your case, `-M wbfm` means that it's demodulating FM in a way compatible to broadcast FM; that implies fixed parameters for deviation, emphasis etc. What you want is really not `rtl_fm`, which primarily is a demo program, not meant to be a flexible do-it-all solution. What you want, showing deviation of a station, does very much sound like a spectrum visualization. Wouldn't a waterfall or even just an instantaneous spectrum visualization be what you want? Best regards, Marcus On Wed, 2018-03-14 at 15:57 -0400, Theodric Young wrote: > Hi, > > I'm new to SDR and I have a question about the data values that are > generated by the rtl_fm program. > > I got rtl_fm running on my system (cygwin running on Windows 7). It is > sending a stream of 16-bit signed integer values to stdout which I can > redirect to a file or pipe to an audio playback system, such as sox. So > when I do this: > > rtl_fm -f 88.1M -M wbfm -s 240k -r120k -g 30 | play -t raw -r 120k -b > 16 -c 1 -e s -V1 - > > I hear sweet, sweet music! Hurray! > > But how do these 16-bit integers relate to the modulation level of the > carrier? I'm assuming that the values are directly proportional to the > instantaneous frequency deviation of the transmitted signal. Is that > right? If so, how do I determine that ratio? I'm hoping to use this to > build a device that shows total modulation (as a percentage of the > maximum modulation of +/- 75kHz) for an FM radio station. > > Also, I'm assuming that the sample-rate of the output data stream needs > to be at least 120kHz because the baseband signal includes the stereo > pilot (19kHz), the stereo subcarrier (38kHz) and an RBDS subcarrier (57 > kHz). > > Any insight would be appreciated. Thanks in advance, > > Theodric Young

1 0

None
by None 15 Mar '18

15 Mar '18

by outgoing.mit.edu (8.13.8/8.12.4) with ESMTP id w2EJvsmv004135 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT) for <osmocom-sdr(a)lists.osmocom.org>; Wed, 14 Mar 2018 15:57:55 -0400 To: osmocom-sdr(a)lists.osmocom.org From: Theodric Young <theodric(a)mit.edu> Subject: Meaning of rtl_fm output values Message-ID: <d96cc71b-6d81-d786-ccd1-708c84eba0ff(a)mit.edu> Date: Wed, 14 Mar 2018 15:57:55 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrPIsWRmVeSWpSXmKPExsUixCmqrHusbmWUwc1tLBb7Jl9hcWD0WHXa I4AxissmJTUnsyy1SN8ugSvjx87tbAX7OSv2bJ/G3sC4lr2LkZNDQsBEYvqcdSxdjFwcQgKL mSQWnj/DCuFcZZSY37eNDcKZxizRv/4YI0iLiICixOTf24FaODjYBNQlJv6zAQkLC2hIrL91 jwXE5hWwkvh96Q0TiM0ioCrxdtsWZhBbVCBGomXJB0aIGkGJkzOfgNUzC5hJzNv8kBnClpfY /nYO8wRG3llIymYhKZuFpGwBI/MqRtmU3Crd3MTMnOLUZN3i5MS8vNQiXRO93MwSvdSU0k2M 4FCS5N/BOKfB+xCjAAejEg+vgdrKKCHWxLLiytxDjJIcTEqivPunrIgS4kvKT6nMSCzOiC8q zUktPsQowcGsJMJ7vxConDclsbIqtSgfJiXNwaIkzutuoh0lJJCeWJKanZpakFoEk5Xh4FCS 4D1cC9QoWJSanlqRlplTgpBm4uAEGc4DNFyuDmR4cUFibnFmOkT+FKMxx5+HL9uYOW68eN3G LMSSl5+XKiXO+x5knABIaUZpHtw0UDq4yHbi3CtGcaDnhHkFQAbyAFMJ3LxXQKuYgFZlblsB sqokESEl1cAYvC/tgHRlS0bd5jnmP/RrNsU/5J6oKV7p8ixCsX/y/3f1+69NufA6bvK/ZD3H 9ONOL50fx7tsVejkM1b7PVkywsPsRnRig7Vbm3R4CnNom/9rs3aJA/Oas4WZ3H7tupb8N8np Qy/bcu5Nib3zr84VOPDxw2mnkitF08Nv2O89u0UxJ+n8wa9KLMUZiYZazEXFiQCH7MfT4gIA AA== X-BeenThere: osmocom-sdr(a)lists.osmocom.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Discussion on Osmocom SDR projects $OsmoSDR, rtl-sdr$" <osmocom-sdr.lists.osmocom.org> List-Unsubscribe: <https://lists.osmocom.org/mailman/options/osmocom-sdr>, <mailto:osmocom-sdr-request@lists.osmocom.org?subject=unsubscribe> List-Archive: <http://lists.osmocom.org/pipermail/osmocom-sdr/> List-Post: <mailto:osmocom-sdr@lists.osmocom.org> List-Help: <mailto:osmocom-sdr-request@lists.osmocom.org?subject=help> List-Subscribe: <https://lists.osmocom.org/mailman/listinfo/osmocom-sdr>, <mailto:osmocom-sdr-request@lists.osmocom.org?subject=subscribe> X-List-Received-Date: Wed, 14 Mar 2018 19:57:59 -0000 Hi, I'm new to SDR and I have a question about the data values that are generated by the rtl_fm program. I got rtl_fm running on my system (cygwin running on Windows 7). It is sending a stream of 16-bit signed integer values to stdout which I can redirect to a file or pipe to an audio playback system, such as sox. So when I do this: rtl_fm -f 88.1M -M wbfm -s 240k -r120k -g 30 | play -t raw -r 120k -b 16 -c 1 -e s -V1 - I hear sweet, sweet music! Hurray! But how do these 16-bit integers relate to the modulation level of the carrier? I'm assuming that the values are directly proportional to the instantaneous frequency deviation of the transmitted signal. Is that right? If so, how do I determine that ratio? I'm hoping to use this to build a device that shows total modulation (as a percentage of the maximum modulation of +/- 75kHz) for an FM radio station. Also, I'm assuming that the sample-rate of the output data stream needs to be at least 120kHz because the baseband signal includes the stereo pilot (19kHz), the stereo subcarrier (38kHz) and an RBDS subcarrier (57 kHz). Any insight would be appreciated. Thanks in advance, Theodric Young

1 0

antenna enquiry/long praise inc
by mary 14 Mar '18

14 Mar '18

1 0

drop in replacement for nonfunctioning "discover_netsdr"
by dale ranta 06 Mar '18

06 Mar '18

The module “discover_netsdr” in “rfspace_source_c.cc” failed everywhere that I tried it, except for MacOS 10.6. Here is a drop in replacement that was tested and found to work on 10.6, 10.11, 10.12, 10.13 and ubuntu 16.04 LTS. #include <net/if.h> #include <ifaddrs.h> class interfaceInformation{ public: std::string name; std::string address; std::string broadcast; }; std::vector<interfaceInformation> interfaceList(); static std::vector < unit_t > discover_netsdr() { std::vector < unit_t > units; std::vector<interfaceInformation> list=interfaceList(); for(int pass=0;pass<2;++pass){ for(size_t n=0;n<list.size();++n){ if(pass == 1){ list[n].broadcast="255.255.255.255"; } //std::cout << "name " << list[n].name << std::endl; //std::cout << "address " << list[n].address << std::endl; //std::cout << "broadcast " << list[n].broadcast << std::endl; int sockTx; int sockRx; if ( (sockTx = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) continue; if ( (sockRx = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ){ close(sockTx); continue; } int sockoptval = 1; setsockopt(sockTx, SOL_SOCKET, SO_REUSEADDR, &sockoptval, sizeof(int)); sockoptval = 1; setsockopt(sockTx, SOL_SOCKET, SO_BROADCAST, &sockoptval, sizeof(int)); struct sockaddr_in host_sa; /* local address */ struct sockaddr_in peer_sa; /* remote address */ struct sockaddr_in peer_sa2; /* remote address */ /* fill in the server's address and data */ memset((char*)&peer_sa, 0, sizeof(peer_sa)); peer_sa.sin_family = AF_INET; peer_sa.sin_addr.s_addr = htonl(inet_network(list[n].address.c_str())); peer_sa.sin_port = htons(DISCOVER_SERVER_PORT); /* fill in the server's address and data */ memset((char*)&peer_sa2, 0, sizeof(peer_sa2)); peer_sa2.sin_family = AF_INET; peer_sa2.sin_addr.s_addr = htonl(inet_network(list[n].broadcast.c_str())); peer_sa2.sin_port = htons(DISCOVER_SERVER_PORT); /* fill in the hosts's address and data */ memset(&host_sa, 0, sizeof(host_sa)); host_sa.sin_family = AF_INET; host_sa.sin_addr.s_addr = htonl(INADDR_ANY); host_sa.sin_port = htons(DISCOVER_CLIENT_PORT); if ( bind(sockTx, (struct sockaddr *)&peer_sa, sizeof(peer_sa)) < 0 ) { close(sockTx); close(sockRx); continue; } if ( bind(sockRx, (struct sockaddr *)&host_sa, sizeof(host_sa)) < 0 ) { perror("binding datagram sock2"); printf("errno %d DISCOVER_SERVER_PORT %d\n",errno,DISCOVER_SERVER_PORT); close(sockTx); close(sockRx); continue; } struct timeval tv; tv.tv_sec = 0; tv.tv_usec = 100000; if ( setsockopt(sockRx, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0 ) { close(sockRx); close(sockTx); continue; } discover_common_msg_t tx_msg; memset( (void *)&tx_msg, 0, sizeof(discover_common_msg_t) ); tx_msg.length[0] = sizeof(discover_common_msg_t); tx_msg.length[1] = sizeof(discover_common_msg_t) >> 8; tx_msg.key[0] = KEY0; tx_msg.key[1] = KEY1; tx_msg.op = MSG_REQ; sendto(sockTx, &tx_msg, sizeof(tx_msg), 0, (struct sockaddr *)&peer_sa, sizeof(peer_sa)); sendto(sockTx, &tx_msg, sizeof(tx_msg), 0, (struct sockaddr *)&peer_sa2, sizeof(peer_sa2)); while ( 1 ) { size_t rx_bytes = 0; unsigned char data[1024*2]; socklen_t addrlen = sizeof(host_sa); /* length of addresses */ int nbytes = recvfrom(sockRx, data, sizeof(data), 0, (struct sockaddr *)&host_sa, &addrlen); if ( nbytes <= 0 ) break; rx_bytes = nbytes; if ( rx_bytes >= sizeof(discover_common_msg_t) ) { discover_common_msg_t *rx_msg = (discover_common_msg_t *)data; if ( KEY0 == rx_msg->key[0] && KEY1 == rx_msg->key[1] && MSG_RESP == rx_msg->op ) { void *temp = rx_msg->port; uint16_t port = *((uint16_t *)temp); std::stringstream buffer; buffer << int(rx_msg->ipaddr[3]) << "." << int(rx_msg->ipaddr[2]) << "." << int(rx_msg->ipaddr[1]) << "." << int(rx_msg->ipaddr[0]); std::string addr=buffer.str(); //std::cout << "addr " << addr << std::endl; unit_t unit; unit.name = rx_msg->name; unit.sn = rx_msg->sn; unit.addr = addr; unit.port = port; units.push_back( unit ); } } } close(sockTx); close(sockRx); } } return units; } std::vector<interfaceInformation> interfaceList() { std::vector<interfaceInformation> list; interfaceInformation c1; struct ifaddrs *addrs,*iloop; char buf[64],buf2[64]; struct sockaddr_in *s4; getifaddrs(&addrs); for (iloop = addrs; iloop != NULL; iloop = iloop->ifa_next) { s4 = (struct sockaddr_in *)(iloop->ifa_addr); buf[0]=0; if(s4){ inet_ntop(iloop->ifa_addr->sa_family, (void *)&(s4->sin_addr), buf, sizeof(buf)); }else{ continue; } s4 = (struct sockaddr_in *)(iloop->ifa_dstaddr); buf2[0]=0; if(s4){ inet_ntop(iloop->ifa_dstaddr->sa_family, (void *)&(s4->sin_addr), buf2, sizeof(buf2)); }else{ continue; } if(!(iloop->ifa_flags & IFF_UP) || !(iloop->ifa_flags & IFF_BROADCAST))continue; c1.name = iloop->ifa_name; c1.address = buf; c1.broadcast = buf2; list.push_back(c1); } freeifaddrs(addrs); return list; }

1 0

RTL-SDR sample bit depth
by John Ackermann N8UR 05 Mar '18

05 Mar '18

Hi -- I'm trying to understand the sampling and decimation structure of the RTL-SDR dongle, to work out the effective number of bits after decimation. From Google and looking at the librtlsdr code (which is beyond my programming depth), I think I've figured out the following. I'd much appreciate verification/correction/amplification. 1. Actual ADC in the RTL-2832U is a single-bit sigma-delta running at some very high rate. 2. This is converted to 28.8 msps at 8 bit depth. 3. 28.8 msps is downsampled to the rate requested by the user and sent over the USB bus as 8 bit unsigned IQ pairs. Based on that, I *think*: a. Any processing gain in the downsample from 28.8 msps/8 bits within the chip is lost because the wire samples are limited to 8 bits. The output is 8 bits dynamic range regardless of the sample rate set. b. THEREFORE... for best dynamic range one wants to set the RTL-2832U to the highest sample rate that avoids lost samples, and do further decimation in the host processor, where the added bits aren't lost on the wire. I'd appreciate any verification or correction of that analysis. Thanks, John

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