DVB-T with board apps on Linux

I wanted an easy way to watch TV quickly on the go. If you have DVB-T/DAB/FM sticks with the famous RTL-SDR Chip 2838 and a tuner like Elonics 4000 or Rafael Micro R820T / T2 or some Fitipowers you are able to achieve this tutorial here. We use VLC and it’s built-in capabilities to decode DVB-T.

I started with a freshly installed Ubuntu. First get sure to have the latest packages.

sudo apt-get update

sudo apt-get upgrade

After that we are going to install VLC player and the w_scan utils

sudo apt-get install vlc w-scan

Now we can make a program list and start the frequency search. For this purpose we use the command underlying. If you come from another country than Germany search for your 2-letter countrycode or be referred to the w-scan manual / man pages to find out for you (pretty straight forward to find your countrycode – its as usual). The >> in the command sends the found frequencies to a file (conf) in the path given. Feel free to specify another path like / (root) or others like the desktop /home/yourusername/Desktop.

w_scan -ft -c DE >> /etc/vlc/channels.conf

You could also go with another output file (experimental …). Just change .conf to the ending .xspf

Get sure, if you start the w_scan command, that your DVB-T stick is plugged in (type in command line “lsusb” without “”s and look out for your device. Also maybe restart or give free the resource if it may be blocked by another program already / or still. Hardware is a bit dumb. After that the scanning starts and needs some time. Your stations are now saved in the file. If you don’t find any stations. your antenna setuo could be bad. I e.g. had 2 antennas that didn’t work out well and then changed to a Yagi-Uda antenna.Now open VLC and go to the Menu > Media > choose device > select DVB-T stick (usually adapter0, you can proof that by navigating in the file explorer). Enter the command with the file to your conf or xspf file:

vlc /path/toyour/file/channels.conf

Or open in VLC via file open to open .conf or .xspf station lists. Now you should enjoy your stations by selecting them in Programs > station. Another, but unstable way (doesn’t save the stations) is to go to this device window and then press “play”. I was able to find approximately 10 working stations.

If you have trouble and have to mount the stick drivers first, use this command to mount the already implemented linux kernel drivers for the RTL stick:

modprobe dvb_stick_usb_rtl28xxu rtl2830 rtl2832

If you want to eliminate the OS drivers for the DVB-T mode and enter in the I/Q sample mode

sudo rmmod rtl28xxu

Under Debian it’s a bit differnt with an editor (add nano or vim in from of the command). Add the following line “blacklist dvb_usb_rtl28xxu”

/etc/modprobe.d/blacklist.conf

GNURadio conference (GRCon15) presentations

The GNU Radio conference (GRCon15) is a yearly conference discussing all matters related to GNU Radio, an open source graphical block based DSP programming application that is compatible with most SDRs, including the RTL-SDR. Many of the presentation slides are now available for viewing on their  website.

There are many interesting presenations like how to start building an SDR from scratch, getting startet with tools like GNU Radio, Pybombs etc., but also more important topics of the near future e.g. how to get GNURadio into undergraduate schedules or how to implement SDR platforms into mobile computing platforms.

Continue reading

Decoding Immarsat geostationary satellite text messages

A nice hack has been published on how to decode satellite-based text messages (STD-C EGC) of an Immarsat geosat. Those messages include information about search and rescue, coast guard, weather and much more. The hack consists of a tutorial on how to build a cheap antenna out of a modified GPS or helix antenna and how to pipe the outputs into SDR# and then to display messages with a program called tdma-demo.exe, which despreads the messages from the time division coding. Continue reading

Spectrum Painting in open bands with HackRF

One of the outcomes of the Chaos Communication camp and the handed out badge (rad10 badge – an adaption of the HackRF) was playing around with the idea of painting pictures on the RF spectrum with the HackRF – a low cost transmit capable software defined radio. This idea works simply by modulating a signal so that it produces a desired image pattern on a frequency domain waterfall display. Continue reading

DesktopSDR.com book release postponed to 5th Sept. 2015

On the official desktopsdr.com website is state since today that their already postponed release date from the 31.st August is postponed to the 5.th September 2015. Let’s hope it’s for the best and that the team can finish everything in time to deliver a nice work. Folks like me would be glad if they would release the first chapter or so, or an Amazon pre-buying link etc.

Educational Videos from Michael Ossmann

Michael Ossmann, the creator of the popular HackRF, shows the basics of digital signal processing (DSP) and gives an introduction into the topic of SDR and the GNU Radio framework in particular. Needed is only the HackRF (or if you are brave any other SDR peripherial e.g. the RTL-SDR dongle). Up until now (August 2015) Michael provided nine lessons, which can be downloaded via http or torrent and which are released under a CC BY license. Continue reading

Black Magic for Computer Scientists

Signals and deeper singal theory is still perceived as “Black Magic” by computer scientists and avoided or overshaded by confuse implementations. Jack Schaedler wanted to change this and introduced a pretty nice looking introduction to circle sines and  signals, condensend in “a compact primer on digital signal processing“. For all those people out there who ever wanted to understand how a DFT or FFT works and only heard little about the topic, this might be a good introduction to it. It is nicely designed and covers all basic topics from discrete signals, to mathematical representations up until Nyquist-theorem or Aliasing. With  embedded moving examples the theory is presented in a nice graphical way for an easy understanding.

DesktopSDR.com free book release

Folks from the University of Strathclyde (Glasgow) are releasing a free PDF book about Software Defined Radio on their page desktopsdr.com. There is also a hardcover and a softcover version planned, which will be retailed on Amazon later. The publication date was said to be the 26th August 2015, now even 31st August is announced on their homepage as print release date.

I’m eager to have a look into the book once it is released and thank all authors in advance for their effort they put into it.


Title: SDR using MATLAB & Simulink and the RTL-SDR
Free PDF download: http://www.desktopsdr.com/download
Softback ISBN : 978-0-9929787-1-6
Hardback ISBN : 978-0-9929787-2-3
Authors: Bob Stewart, Kenny Barlee, Dale Atkinson, Louise Crockett

Modification of sodera.de

In the next weeks this page will be transferred to English, because i think i can reach a bigger audience, than in German.

ToDo:

  • Translate posts from German to English
  • Design modifications
  • New articles
  • Test new plugins for comments, community etc.