Software Defined Radio on Raspberry Pi

I've been playing around with this USB dongle for software defined radio.  I got it to work in Kali Linux (VM).  I was able to send ADS-B packets from the Kali VM to the windows host which was running adsbSCOPE 2.63.  I saw that some people have used a Raspberry Pi to receive the signals and rebroadcast over a network, so I wanted to try that next.

I first looked for the rtl-sdr drivers using apt-get in Raspian.  Of course, that package wasn't there.  Thankfully, there are some simple instructions for getting the source code for the driver and building it here.

Here is what I did.

1. Update my version of Raspian.  This updates the package lists and then installs any updated packages.
• root@rapberrypi:~# apt-get update
• root@rapberrypi:~# apt-get uprade
2.  Install packages needed to build packages from source.
• root@rapberrypi:~# apt-get install git
• root@rapberrypi:~# apt-get install cmake
• root@rapberrypi:~# apt-get libusb-1.0-0-dev
• I tried to install build-essential, but it was already installed
3. Create a new directory.  I used the pi home directory.
• root@rapberrypi:~# cd /home/pi
• root@rapberrypi:/home/pi# mkdir src
• root@rapberrypi:/home/pi# cd src
4. Get the source code
• root@rapberrypi:/home/pi/src# git clone git://git.osmocom.org/rtl-sdr.git
5. Build and install it
• root@rapberrypi:/home/pi/src# cd rtl-sdr
• root@rapberrypi:/home/pi/src/rtl-sdr# mkdir build
• root@rapberrypi:/home/pi/src/rtl-sdr# cd build
• root@rapberrypi:/home/pi/src/rtl-sdr/build# cmake ../
• root@rapberrypi:/home/pi/src/rtl-sdr/build# make
• root@rapberrypi:/home/pi/src/rtl-sdr/build# make install
• root@rapberrypi:/home/pi/src/rtl-sdr/build# ldconfig

ldconfig updates shared libraries cache.  It is useful in that it keeps programs from having to search through all of the library paths to find the correct version of a shared library.

1. Test it.  I ran rtl_test and then rtl_adsb to see if I got any output.
• root@rapberrypi:/home/pi/src/rtl-sdr/build# rtl_test
  Found 1 device(s):
    0:  ezcap USB 2.0 DVB-T/DAB/FM dongle
  ETC...
• root@rapberrypi:/home/pi/src/rtl-sdr/build# rtl_adsb
  Found 1 device(s):
    0:  Realtek, RTL2838UHIDIR, SN: 00000001
  
  Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
  Found Rafael Micro R820T tuner
  Tuner gain set to automatic.
  Tuned to 1090000000 Hz.
  Sampling at 2000000 Hz.
  Exact sample rate is: 2000000.052982 Hz
  *aa7b30d2cec4af08045508ad3d47;
  ETC...

Once I got that working, I tried to send it to adsbSCOPE on the windows machine using netcat.  The command is given in the rtl_adsb help.
root@raspberrypi:/home/pi# rtl_adsb | netcat -lp 7000

Then in adsbSCOPE under 'other | Network' menu, I set the network setting to listen to the Raspberry Pi's IP address and port 7000 for the RAW-data-client.  I made sure the the RAW-data-client was active under the 'other | Network' menu.  

adsbSCOPE Network Setup Window

I was receiving packets and displaying aircraft location.  Not too many, but that might have to do with the antenna and location that I was receiving from.

adsbSCOPE Main Window, Decoding Location of One Airplane