Rtl-sdr – rtl-sdr – Open Source Mobile Communications
DVB-T dongles based on the Realtek RTL2832U can be used as a cheap SDR, since the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation. The possibility of this has been discovered by Eric Fry (History and Discovery of RTLSDR). Antti Palosaari has not been involved in development of rtl-sdr.
The RTL2832U outputs 8-bit I/Q-samples, and the highest theoretically possible sample-rate is 3.2 MS/s, however, the highest sample-rate without lost samples that has been tested wit regular USB controllers so far is 2.4 MS/s. A stable sample-rate of 3.2 MS/s without lost samples is only possible with the Etron EJ168/EJ188/EJ198 series of host controllers due to their specific maximum latency. The frequency range is highly dependent of the used tuner, dongles that use the Elonics E4000 offer the widest possible range (see table below).
Tuner
Frequency range
Elonics E4000
52 – 2200 MHz with a gap from 1100 MHz to 1250 MHz (varies)
Rafael Micro R820T
24 – 1766 MHz
Rafael Micro R828D
24 – 1766 MHz
Fitipower FC0013
22 – 1100 MHz (FC0013B/C, FC0013G has a separate L-band input, which is unconnected on most sticks)
Fitipower FC0012
22 – 948.6 MHz
FCI FC2580
146 – 308 MHz and 438 – 924 MHz (gap in between)
Mục lục bài viết
Supported Hardware¶
Note: Many devices with EEPROM have 0x2838 as PID and RTL2838 as product name, but in fact all of them have an RTL2832U inside.br
Realtek never released a chip marked as RTL2838 so far.
The following devices are known to work fine with RTLSDR software:
VID
PID
tuner
device name
0x0bda
0x2832
all of them
Generic RTL2832U (e.g. hama nano)
0x0bda
0x2838
E4000
ezcap USB 2.0 DVB-T/DAB/FM dongle
0x0ccd
0x00a9
FC0012
Terratec Cinergy T Stick Black (rev 1)
0x0ccd
0x00b3
FC0013
Terratec NOXON DAB/DAB+ USB dongle (rev 1)
0x0ccd
0x00d3
E4000
Terratec Cinergy T Stick RC (Rev.3)
0x0ccd
0x00e0
E4000
Terratec NOXON DAB/DAB+ USB dongle (rev 2)
0x185b
0x0620
E4000
Compro Videomate U620F
0x185b
0x0650
E4000
Compro Videomate U650F
0x1f4d
0xb803
FC0012
GTek T803
0x1f4d
0xc803
FC0012
Lifeview LV5TDeluxe
0x1b80
0xd3a4
FC0013
Twintech UT-40
0x1d19
0x1101
FC2580
Dexatek DK DVB-T Dongle (Logilink VG0002A)
0x1d19
0x1102
?
Dexatek DK DVB-T Dongle (MSI DigiVox mini II V3.0)
0x1d19
0x1103
FC2580
Dexatek Technology Ltd. DK 5217 DVB-T Dongle
0x0458
0x707f
?
Genius TVGo DVB-T03 USB dongle (Ver. B)
0x1b80
0xd393
FC0012
GIGABYTE GT-U7300
0x1b80
0xd394
?
DIKOM USB-DVBT HD
0x1b80
0xd395
FC0012
Peak 102569AGPK
0x1b80
0xd39d
FC0012
SVEON STV20 DVB-T USB & FM
People over at reddit are collecting a list of other devices that are compatible.
If you find a device that is not yet in the device list but should be supported, please send the VID/PID and additional info (used tuner, device name) to our mailing list.
This is the PCB of the ezcap-stick:
More pictures can be found here.
Much software is available for the RTL2832. Most of the user-level packages rely on the librtlsdr library which comes as part of the rtl-sdr codebase. This codebase contains both the library itself and also a number of command line tools such as rtl_test, rtl_sdr, rtl_tcp, and rtl_fm. These command line tools use the library to test for the existence of RTL2832 devices and to perform basic data transfer functions to and from the device.
Because most of the RTL2832 devices are connected using USB, the librtlsdr library depends on the libusb library to communicate with the device.
At the user level, there are several options for interacting with the hardware. The rtl-sdr codebase contains a basic FM receiver program that operates from the command line. The rtl_fm program is a command line tool that can initialize the RTL2832, tune to a given frequency, and output the received audio to a file or pipe the output to command line audio players such as the alsa aplay or the sox play commands. There is also the rtl_sdr program that will output the raw I-Q data to a file for more basic analysis.
For example, the following command will do reception of commercial wide-band FM signals:
rtl_fm -f 96.3e6 -M wbfm -s 200000 -r 48000 - | aplay -r 48k -f S16_LE
On a Mac, a similar command that works is as follows. This assumes that the sox package is installed, ‘port install sox’:
rtl_fm -f 90100000 -M wbfm -s 200000 -r 48000 - | play -r 48000 -t s16 -L -c 1 -
If you want to do more advanced experiments, the GNU Radio collection of tools can be used to build custom radio devices. GNU Radio can be used both from a GUI perspective in which you can drag-and-drop radio components to build a radio and also programmatically where software programs written in C or Python are created that directly reference the internal GNU Radio functions.
The use of GNU Radio is attractive because of the large number of pre-built functions that can easily be connected together. However, be aware that this is a large body of software with dependencies on many libraries. Thankfully there is a simple script that will perform the installation but still, the time required can be on the order of hours. When starting out, it might be good to try the command line programs that come with the rtl-sdr package first and then install the GNU Radio system later.
Binary Builds¶
While Osmocom in general is a very much Linux-centric development community, we are now finally publishing automatic weekly Windows binary builds for the most widely used Osmocom SDR related projects: rtl-sdr and osmo-fl2k.
You can find the binaries at
The actual builds are done by
You can find the binaries atThe actual builds are done by roox who is building them using MinGW on OBS, see
The status of the osmocom binary publish job, executed once per week from now on, can be found at https://jenkins.osmocom.org/jenkins/view/All%20no%20Gerrit/job/Osmocom-OBS_MinGW_weekly_publish/
Source Code¶
The rtl-sdr code can be checked out with:
git clone https://gitea.osmocom.org/sdr/rtl-sdr.git
It can also be browsed via gitea, and there’s an official mirror on github that also provides packaged releases.
If you are going to “fork it on github” and enhance it, please contribute back and submit your patches to: osmocom-sdr at lists.osmocom.org
A gr-osmosdr GNU Radio source block for OsmoSDR and rtl-sdr is available. Please install a recent gnuradio (>= v3.6.4) in order to be able to use it.
Building the software¶
rtlsdr library & capture tool¶
You have to install development packages for libusb1.0 and can either use cmake or autotools to build the software.
Please note: prior pulling a new version from git and compiling it, please do a “make uninstall” first to properly remove the previous version.
Building with cmake:
cd rtl-sdr/ mkdir build cd build cmake ../ make sudo make install sudo ldconfig
In order to be able to use the dongle as a non-root user, you may install the appropriate udev rules file by calling cmake with -DINSTALL_UDEV_RULES=ON argument in the above build steps.
cmake ../ -DINSTALL_UDEV_RULES=ON
Building with autotools:
cd rtl-sdr/ autoreconf -i ./configure make sudo make install sudo ldconfig
The built executables (rtl_sdr, rtl_tcp and rtl_test) can be found in rtl-sdr/src/.
In order to be able to use the dongle as a non-root user, you may install the appropriate udev rules file by calling
sudo make install-udev-rules
[RelWithDebInfo.zip pre-built Windows version”:http://lists.osmocom.org/mailman/listinfo/osmocom-sdr]
Gnuradio Source¶
The Gnu Radio source requires a recent gnuradio (>= v3.7 if building master branch or 3.6.5 when building gr3.6 branch) to be installed.
The source supports direct device operation as well as a tcp client mode when using the rtl_tcp utility as a spectrum server.
Please note: prior pulling a new version from git and compiling it, please do a “make uninstall” first to properly remove the previous version.
Please note: you always should build & install the latest version of the dependencies (librtlsdr in this case) before trying to build the gr source. The build system of gr-osmosdr will recognize them and enable specific source/sink components thereafter.
Building with cmake (as described in the gr-osmosdr wiki page):
git clone https://gitea.osmocom.org/sdr/gr-osmosdr cd gr-osmosdr/
If you are building for gnuradio 3.6 series, you have to switch to the gr3.6 branch as follows
git checkout gr3.6
then continue with
mkdir build cd build/ cmake ../
Now cmake should print out a summary of enabled/disabled components. You may disable certain components by following guidelines shown by cmake. Make sure the device of your interest is listed here. Check your dependencies and retry otherwise.
-- ###################################################### -- # gr-osmosdr enabled components -- ###################################################### -- * Python support -- * Osmocom IQ Imbalance Correction -- * sysmocom [[OsmoSDR]] -- * [[FunCube]] Dongle -- * IQ File Source -- * Osmocom RTLSDR -- * RTLSDR TCP Client -- * Ettus USRP Devices -- * Osmocom [[MiriSDR]] -- * [[HackRF]] Jawbreaker -- -- ###################################################### -- # gr-osmosdr disabled components -- ###################################################### -- -- Building for version: 4c101ea4 / 0.0.1git -- Using install prefix: /usr/local
Now build & install
make sudo make install sudo ldconfig
NOTE: The osmocom source block (osmocom/RTL-SDR Source) will appear under ‘Sources’ category in GRC menu.
For initial tests we recommend the multimode receiver gnuradio companion flowgraph (see “Known Apps” table below).
You may find more detailed installation instructions in this recent tutorial.
Automated installation¶
Marcus D. Leech has kindly integrated the forementioned build steps into his gnuradio installation script at “This is the most user-friendly option so far.
h2. Mailing List
We discuss both OsmoSDR as well as rtl-sdr on the following mailing list: [mailto:[email protected]].
You can subscribe and/or unsubscribe via the following link: https://lists.osmocom.org/mailman/listinfo/osmocom-sdr
Please make sure to read the MailingListRules before posting.
Example: To tune to 392.0 MHz, and set the sample-rate to 1.8 MS/s, use:
./rtl_sdr /tmp/capture.bin -s 1.8e6 -f 392e6
to record samples to a file or to forward the data to a fifo.
If the device can’t be opened, make sure you have the appropriate rights to access the device (install udev-rules from the repository, or run it as root).
Example:
rtl_tcp -a 10.0.0.2 [-p listen port (default: 1234)":http://www.sbrac.org/files/build-gnuradio]. Found 1 device(s). Found Elonics E4000 tuner Using Generic RTL2832U (e.g. hama nano) Tuned to 100000000 Hz. listening... Use the device argument 'rtl_tcp=10.0.0.2:1234' in [[OsmoSDR]] (gr-osmosdr) source to receive samples in GRC and control rtl_tcp parameters (frequency, gain, ...).
use the rtl_tcp=… device argument in gr-osmosdr source to receive the samples in GRC and control the rtl settings remotely.
This application has been successfully crosscompiled for ARM and MIPS devices and is providing IQ data in a networked ADS-B setup at a rate of 2.4MSps. The gr-osmosdr source is being used together with an optimized gr-air-modes version (see Known Apps below).
It is also available as a package in OpenWRT.
A use case is described here.
To check the possible tuning range (may heavily vary by some MHz depending on device and temperature), call
rtl_test -t
To check the maximum samplerate possible on your machine, type (change the rate down until no sample loss occurs):
rtl_test -s 3.2e6
A samplerate of 2.4e6 is known to work even over tcp connections (see rtl_tcp above). A sample rate of 2.88e6 may work without lost samples but this may depend on your PC/Laptop’s host interface.
Using the data¶
A samplerate of 2.4e6 is known to work even over tcp connections (see rtl_tcp above). A sample rate of 2.88e6 may work without lost samples but this may depend on your PC/Laptop’s host interface.
To convert the data to a standard cfile, following GNU Radio Block can be used:br
The GNU Radio Companion flowgraph is available as rtl2832-cfile.grc. It is based on the FM demodulation flowgraph posted by Alistair Buxton on this thread.
Please note: for realtime operation you may use fifos (mkfifo) to forward the iq data from the capture utility to the GRC flowgraph.
You may use any of the the following gnuradio sources (they are equivalent):
What has been successfully tested so far is the reception of Broadcast FM and air traffic AM radio, tetra, gmr, GSM, ADS-B and POCSAG.
Tell us your success story with other wireless protocols in ##rtlsdr channel on the libera IRC network.
Known Apps¶
The following 3rd party applications and libraries are successfully using either librtlsdr directly or the corresponding gnuradio source (gr-osmosdr):
Also take a look at the applications which use rtl-sdr through gr-osmosdr.
Using our lib? Tell us! Don’t? Tell us why! 🙂
Multiple GMR-carriers can be seen in a spectrum view with the full 3.2 MHz bandwidth (at 3.2 MS/s).
rtl-sdr is developed by Steve Markgraf, Dimitri Stolnikov, and Hoernchen, with contributions by Kyle Keen, Christian Vogel and Harald Welte.
