Gqrx
====

Gqrx is an experimental software defined radio receiver implemented using GNU
Radio and the Qt GUI toolkit. Currently it works on Linux and Mac and supports
the following devices:
- Funcube Dongle Pro and Pro+
- RTL2832U-based DVB-T dongles (rtlsdr via USB and TCP)
- OsmoSDR
- USRP
- HackRF
- Nuand bladeRF
- RFspace SDR-IQ, SDR-IP, NetSDR and Cloud-IQ
- Airspy
- any other device supported by the gr-osmosdr library

Gqrx can operate as a traditional AM/FM/SSB receiver with audio output or as an
FFT-only instrument. There are also various hooks for interacting with external
application using nertwork sockets.


Download
--------

Gqrx is distributed as source code package and binaries for Linux. Mac support
is avaialble through macports. Please see http://gqrx.dk/download for a list of
official and third party download resources.


Usage
-----

It is strongly recommended to run the "volk_profile" gnuradio utility before
running gqrx. This will detect and enable processor specific optimisations and
will in many cases give a significant performance boost.

The first time you start gqrx it will open a device configuration dialog.
Supported devices that are connected to the computer are discovered
automatically and you can select any of them in the drop-down list.

If you don't see your device listed in the drop-down list it could be because:
- The driver has not been included in a binary distribution
- The udev rule has not been properly configured
- Linux kernel driver is blocking access to the device

You can test your device using device specific tools, such as rtl_test,
airspy_rx, hackrf_transfer, qthid, etc.

Gqrx supports multiple configurations and sessions if you have several devices
or if you want to use the same device under different configurations. You can
load a configuration from the GUI or using the -c command line argument. See
"gqrx --help" for a complete list of command line arguments.

Tutorials and howtos are being written and published on the website
http://gqrx.dk/


Known problems
--------------

See the bug tracker on Github: https://github.com/csete/gqrx/issues


Getting help and reporting bugs
-------------------------------

There is a Google group for discussing anything related to Gqrx:
https://groups.google.com/forum/#!forum/gqrx
This includes getting help with installation and troubleshooting. Please
remember to provide detailed description of your problem, your setup, what
steps you followed, etc.

Please stick around and help others with their problems. Otherwise, if only
developers provide user support there will be no more time for further
development.


Installation from source
------------------------

Gqrx can be compiled using qmake or cmake.

The source code is hosted on Github: https://github.com/csete/gqrx

To compile gqrx from source you need the following dependencies:
- GNU Radio 3.7 with the following components:
    - gnuradio-runtime
    - gnuradio-analog
    - gnuradio-digital
    - gnuradio-blocks
    - gnuradio-filter
    - gnuradio-fft
    - gnuradio-audio
    - gnuradio-pmt
- The gr-iqbalance library (optional)
- At least one of:
    - Funcube Dongle Pro driver via gnuradio-fcd
    - UHD driver via gnuradio-uhd
    - Funcube Dongle Pro+ driver from https://github.com/dl1ksv/gr-fcdproplus
    - RTL-SDR driver from http://cgit.osmocom.org/cgit/rtl-sdr/
    - OsmoSDR driver from http://cgit.osmocom.org/cgit/osmo-sdr/
    - HackRF Jawbreaker driver from http://greatscottgadgets.com/hackrf/
- gnuradio-osmosdr from http://cgit.osmocom.org/cgit/gr-osmosdr/
- pulseaudio (Linux only and optional)
- Qt 4.7 or later with the following components:
    - Core
    - GUI
    - Network
    - Widgets (Qt 5 only)
    - Svg (runtime only)
- cmake version >= 3.2.0 if you wish to build using cmake.

To build using qmake, you can either open the gqrx.pro file in Qt Creator and
build, or on the command line:
<pre>
$ git clone https://github.com/csete/gqrx.git gqrx.git
$ cd gqrx.git
$ mkdir build
$ cd build
$ qmake ..
$ make
</pre>

Using cmake, gqrx can be compiled from within Qt Creator or in a terminal:

For command line builds:
<pre>
$ git clone https://github.com/csete/gqrx.git gqrx.git
$ cd gqrx.git
$ mkdir build
$ cd build
$ cmake ..
$ make
</pre>
On some systems, the default cmake release builds are "over optimized" and
perform poorly. In that case try forcing -O2 using
<pre>
export CXXFLAGS=-O2
</pre>
before the cmake step.

For Qt Creator builds:
<pre>
$ git clone https://github.com/csete/gqrx.git gqrx.git
$ cd gqrx.git
$ mkdir build
Start Qt Creator
Open gqrx.git/CMakeLists.txt file
At the dialog asking for build location, select gqrx.git/build
click continue
If asked to choose cmake executable, do so
click continue
click the run cmake button
click done
optionally, on the Projects page, under Build Steps/Make/Additional arguments,
	enter -j4 (replacing 4 with the number of cores in your CPU).
Use Qt Creator as before
</pre>

Credits and License
-------------------

Gqrx is designed and written by Alexandru Csete OZ9AEC, and it is licensed
under the GNU General Public License.

Some of the source files were adopted from Cutesdr by Moe Weatley and these
come with a Simplified BSD license.

Following people and organisations have contributed to gqrx:


TODO: Credits for bookmarks


Alex Grinkov:
- FM stereo demodulator.

Anthony Willard:
- Various fixes and improvements

Bastian Bloessl:
Pavel Stano:
- RDS support via gr-rds.

Chris Kuethe:
- Fractional PPM correction.

Christian Lindner DL2VCL:
Stefano Leucci:
- Bookmarks implementation.

Elias Önal:
- Building Gqrx on Mac OS X.
- Crash recovery dialog.

Frank Brickle, AB2KT:
Bob McGwier, N4HY:
- Noise blanker (from dttsp).

Göran Weinholt, SA6CJK:
- Various GUI improvements.

Jiří Pinkava:
- Port to gnuradio 3.7 API.

Kobra @ Xiatek:
- Auto squelch.

Michael Dickens:
- Bugfixes on OSX.

Moe Weatley:
- FFT plotter and waterfall.
- Frequency selector.
- Signal strength indicator.
- AGC

Nadeem Hasan:
- Bug fixes.

Nokia:
- QtColorPicker widget.

Stefano Leucci:
- Peak detection and hold for the FFT plot.

Timothy Reaves:
- UI layout fixes for Mac.
- cmake build files

Vesa Solonen:
- DC removal in AM demodulator.

Vincent Pelletier
- Initial work on the horizontal zooming / scrolling.

Will Scales
- Bug fixes.

Also thanks to Volker Schroer and Alexey Bazhin for bringing Funcube Dongle
Pro+ support to GNU Radio and Gqrx.

Some of the icons are from the GNOME and Tango icon themes. The scope.svg icon
is based on the utilities-system-monitor.svg icon from the Mint-X icon theme
licensed under GNU GPL.

Let me know if somebody or someting is missing from the list!

Alex OZ9AEC
