This document discusses software defined radio (SDR) and various low-cost SDR devices that can be used for experimenting with radio signals, including RTL-SDR USB dongles, HackRF, NooElec SDR sticks, and FUNcube Dongles. It provides information on software like GNU Radio, Gqrx, rtl-sdr library, ViewRF, and OpenBTS for processing radio signals on devices like the BeagleBone Black.

1. Fun with bits of ether:
Software Defined Radio (SDR)
NERP Meetup Mar-31-2014
(Not Exclusively Raspberry Pi)
Presenter: Drew Fustini
@pdp7 / drew@pdp7.com
Video Playlist:
https://www.youtube.com/playlist?list=PLa1tazUyp-oM
Pumping Station: One
Chicago Hackerspace

2. Software Defined Radio (SDR)
● Application of Digital Signal Processing to radio
waveforms
● Similar to software-based digital audio
techniques
● Sound card digitizes audio waveforms
● Software radio peripheral digitizes radio
waveforms.
● Like very fast sound card with speaker &
microphone replaced by an antenna.
● Implement virtually any wireless technology:
Bluetooth, ZigBee, cellular technologies, FM, etc
*text on this slide from: https://www.kickstarter.com/projects/mossmann/hackrf-an-open-source-sdr-platform

3. ● http://gnuradio.org/redmine/projects/gnuradio/wiki
● GNU Radio is a free & open-source software
development toolkit that provides signal processing
blocks to implement software radios.
● It can be used with readily-available low-cost external
RF hardware to create software-defined radios, or
without hardware in a simulation-like environment.
● It is widely used in hobbyist, academic and commercial
environments to support both wireless communications
research and real-world radio systems.

4. FUNcube Concept
“The original FUNcube Dongle concept:
receiving information from space as part of a
global educational collaboration project”

5. FUNcube Dongle Pro+
http://www.funcubedongle.com/
● 125 GBP / $208 USD
● Guaranteed coverage:
– 150kHz to 1.9GHz
– Gap between 240MHz and 420MHz
● “FUNcube Dongles are the ground receiver for the
FUNcube Satellite project”
● “It’s also all-mode: this means that it’s not just limited
to narrow band FM reception.”

7. HackRF: open source SDR platform
● operates from 30 MHz to 6 GHz, a wider
range than any SDR peripheral
● used to transmit or receive radio signals. It
operates in half-duplex mode: it can transmit
or receive
● Max bandwidth is 20 MHz, about 10 times
the bandwidth of TV tuner dongles popular for
SDR
● used for high speed digital radio applications
such as LTE or 802.11g
● Post-kickstarter, expected retail ~$300:
http://greatscottgadgets.com/hackrf/

8. HackRF Hardware
● LPC43xx ARM Cortex-M4 microcontroller
● CoolRunner-II CPLD (may switch to MAX V)

9. Cheap USB adapters
as SDR receiver
● Find cheap <$30 USB DVB-T adapters from
many sources online
● DVB-T is used to broadcast TV in Europe
● Libraries have been written to use USB DVB-T
with certain a software defined radio

10. Adafruit SDR USB stick
If you've ever been curious about software defined radio (SDR), this USB stick is the
easiest way possible to have fun with a powerful, configurable receiver.
● $22: Software Defined Radio Receiver USB Stick - RTL2832 w/R820T
●
RTL2832U and R820T tuner with an MCX RF connector
●
Tune into signals from 24MHz to 1850MHz.
● Use a computer (with Windows, Mac, or Linux) to tune into:
– FM Radio
– AM signals (but not AM radio)
– CW (morse code!)
– unencrypted radio signals (such as those used by many police and fire
departments)
– POCSAG pagers
●
basic 'DVB-T' antenna

11. NooElec SDR stick on Amazon
● $20: NooElec Brand RTL-SDR, FM+DAB,
DVB-T USB Stick Set with RTL2832U &
R820T. Great SDR for SDR#, HDSDR, and
Other Popular SDR Software Packages
● http://www.amazon.com/NooElec-RTL-SDR-RTL2

12. rtl-sdr library
● http://sdr.osmocom.org/trac/wiki/rtl-sdr
● DVB-T dongles based on the Realtek
RTL2832U can be used as a cheap SDR
● chip allows transferring the raw I/Q samples to
the host, which is officially used for
DAB/DAB+/FM demodulation.
● History and Discovery of RTLSDR

13. rtl-sdr supported devices
● http://sdr.osmocom.org/trac/wiki/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 so far is 2.56 MS/s. The frequency range is highly dependent of the
used tuner, dongles that use the Elonics E4000 offer the widest possible range (see
table below).
●
Elonics E4000 52 - 2200 MHz with a gap from 1100 MHz to 1250 MHz (varies)
●
Rafael Micro R820T24 - 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)

14. Build rtl-sdr on BeagleBone Black
● Using Angstrom on eMMC
● opkg update
● opkg install libusb-1.0-dev
● git clone git://git.osmocom.org/rtl-sdr.git
● Follow commands in my GitHub Gist:
– https://gist.github.com/pdp7/5503462

15. Test rtl-sdr
From GitHub Gist:
https://gist.github.com/pdp7/8683297
root@beaglebone:~# rtl_eeprom
Found 1 device(s):
0: Generic RTL2832U OEM
Using device 0: Generic RTL2832U
OEM
Found Rafael Micro R820T tuner

16. Play FM radio station 96.3MHz
(using Adafruit USB $5 audio adapter)
root@beaglebone:~# nice -n -10 rtl_fm -f 96.3e6 -M wbfm -r 48000 -
| aplay -r 48k -f S16_LE
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain set to automatic.
Tuned to 96571000 Hz.
Oversampling input by: 6x.
Oversampling output by: 1x.
Buffer size: 8.03ms
Exact sample rate is: 1020000.026345 Hz
Sampling at 1020000 S/s.
Output at 170000 Hz.
Playing raw data 'stdin' : Signed 16 bit Little Endian, Rate 48000
Hz, Mono

17. Alternative if no USB audio adapter
● http://www.meetup.com/Southeast-Michigan-Beagle
● Listening to audio via my Mac using
BeagleBone connected to tuner. 'sox' installed
on my Mac for the 'play' app. 'rtl_fm' :
● ssh root@192.168.7.2 "nice -n -10 rtl_fm -W -f
96.3M" | play -r 32k -t raw -e signed-integer -b
16 -c 1 -V1 --buffer 100000 -

18. rtlizer: RF Spectrum Analyzer
● http://www.oz9aec.net/index.php/beaglebone/480-rtliz

19. ViewRF: RF Spectrum Analyzer
● http://hackaday.com/2013/09/09/an-rtl-sdr-spectrum

20. Gqrx
http://gqrx.dk/

21. Gqrx by Alexandru Csete
● http://gqrx.dk/
● Open source software defined radio receiver
powered by the GNU Radio SDR framework and
the Qt graphical toolkit
● Packaged for Ubuntu Linux & Mac OS X
● Supported Hardware:
http://gqrx.dk/supported-hardware
● Videos:
https://www.youtube.com/user/oz9aec/videos

22. Run your own GSM base station!
● http://openbts.org/
● OpenBTS is a Unix application that uses a
software radio to present a GSM air interface
to standard 2G GSM handset and uses a SIP
softswitch or PBX to connect calls
● Range Networks SDR1 Open Source
Software-Defined Radio:
http://openbts.org/sdr1.html

23. The Amp Hour interviews
● HackRF creator:
http://www.theamphour.com/the-amp-hour-161-gifted-grimg
● “Matt started and still runs Ettus Research, now a 12
person Software Defined Radio (SDR) company
located in the Bay Area”
http://www.theamphour.com/the-amp-hour-101-quality-quad
● Universal Software Radio Peripheral (USRP) products
are computer-hosted software radios:
http://en.wikipedia.org/wiki/Universal_Software_Radio_Peri
●