Video: AMBE exposed

AMBE is a voice compression algorithm employed in vocoder chips used by DVSI Inc., and is commonly used in Icom’s D-Star, Yaesu’s Fusion, APCO-25, DMR, Opensky and other digital formats on the amateur, commercial and public safety frequencies. In this talk from last September’s TAPR/DCC conference in Austin, TX, Bruce Perens K6BP presented his views […]

Video: FlexRadio open API

During the TAPR/ARRL Digital Communications Conference in Austin last September, Stephen Hicks N5AC gave this presentation on interfacing with FlexRadio using their open API. Part II of this presentation was given by Graham Haddock KE9H, and discussed the FlexRadio wavefrom API. It is available from HamRadioNow. FlexRadio produces a series of high-end SDR’s, with the […]

Cheap entropy using RTL-SDR dongle

We’ve seen the RTL-SDR dongle used for a number of interesting projects, but here’s an unusual one not directly related to signal monitoring. Noel Bourke was considering the topic of entropy and randomness as it relates to encryption and came up with a unique use for the RTL-SDR. When RTL-SDRs came on the market back […]

Tutorial: GNU Radio with the HackRF SDR

Michael Ossmann, one of the developers of the amazing and affordable HackRF SDR transceiver, is releasing a tutorial series on using GNU Radio. “This ongoing video series will be a complete course in Software Defined Radio (SDR). In this course, you’ll build flexible SDR applications using GNU Radio through exercises that will help you learn […]

Tutorials: GNU Radio for beginners has been revamping their website, updating information on the latest release. As part of this process Marcus has posted a new seven part tutorial series on GNU Radio. “Our task is to build a beginner-level tutorial, which will then live on the static part of the web site. Someone put it as an “online […]

Garage door signal hacking using RTL-SDR and TI Chronos watch

Students Ido Livneh and Gil Freidlin from Tel Aviv University have been experimenting with garage door opener signals using the TI Chronos watch and RTL-SDR dongle. Their technique involves using the SDR along with HDSDR software to acquire and record the signal, which is then analyzed using Python based tools and encoded for loading onto […]

Analysing 433 Mhz transmitters with RTL-SDR

Yashin has posted this tutorial at ArcanumX demonstrating how to read and decode 433 MHz digital data transmissions. “I intend to demonstrate how the RTL-SDR can be used to sniff 433 Mhz transmitters. These are pretty cheap and can be found in a lot of appliances including alarm sensors. This post is also intended to […]

OHM2013: Hacking the radio spectrum with GNURadio

At the OHM2013 conference held last summer outside Amsterdam, J. M. Friedt discussed his use of GNURadio as a signal processing prototyping tool. He writes, “We demonstrate the use of this software environment for implementing new digial communication mode decoding algorithms, qualifying low frequency circuits by using the audio card as a network analyzer, all […]

Hak5 video: quadcopter with WiFi enabled Linux computer and RTL-SDR

What happens when you send up a quadcopter equipped with a Linux box, WiFi and an RTL-SDR dongle? Darren and company from Hak5 decided to find out. Their project used the SDR to receive ADS-B signals from aircraft hundreds of miles away. The Hak5 team took a quadcopter up on top of a high mountain, […]

How to make your own custom GNU Radio blocks – the C++ way

If you’re a GNU Radio user you know that most of the functions you need are contained the stock group of GNU Radio blocks. However, there are times when you may want to code up a custom block to perform a unique function not found on the stock blocks. Jean-Benoit Larouche has posted the first […]

Nutaq’s SDR project idea contest

Tristan Martin from Nutaq writes to inform us of their academic contest (US only) for winning a PicoSDR kit with MIMO OFDM ref design (FPGA), it supports GNU Radio (GigE and PCIe). “You can submit with an existing (ongoing) project, it doesn’t have to be a “new” project. We do NOT get involved in the […]

Video tutorial: OFDM packet transceivers with GNU radio

Orthogonal frequency-division multiplexing or OFDM is a method of encoding digital data on multiple carrier frequencies. At this presentation from them recent FOSDEM 2014 conference in Brussels, Martin Braun explained the use of GNU Radio software and an SDR transceiver to explore OFDM block basics, how to set up links between nodes and how to […]

RTL-SDR wide spectrum analyzer

Claudio Giuliani has designed an RTL-SDR based wide spectrum analyzer. The code is available on AlterVista. Software prerequisites are a Linux box (no Windows/OSX version) with Gnuradio and rtl_sdr utilities installed. The spectrum analyzer program is a frontend GUI of rtl_power for spectrum visualization and control and is coded in Basic for Gambas (a sort […]

Academic paper: hacking with RF replay attacks

If you’re new to RF hacking you may have heard the term “replay attack” and wondered what it takes to implement one. In this academic presentation Practicing a Record-and-Replay System on USRP a group of researchers from the Shenzhen Key Lab of Advanced Communications and Information Processing and Shenzhen University, give a succinct and practical […]

Listening to D-STAR digital voice with DSD 1.7

Brazilian amateur radio operator PU2VLW has written a post (in Portugese) detailing how to use DSD version 1.7 to decode amateur radio D-STAR digital voice transmissions. (Google translate may be helpful.) DSD can be downloaded as source from GitHub. His setup uses a Windows machine running SDR# to receive the D-STAR signal using an RTL-SDR […]

RTLAMR: an RTL-SDR receiver for 900 MHz smart meters

It never ceases to amaze how many projects are developed making use of the RTL-SDR dongle. Bemasher has developed a software tool which interprets the signals in the 900 MHz ISM band sent from smart electric meters which are growing in popularity among utility companies. This project is a proof of concept software defined radio […]

RTL_FM_Python: An API and web interface for controlling RTL_FM

Here’s an interesting piece of open source code known as RTL_FM_Python for controlling the RTL-SDR dongle. “This is a Python library built upon the RTL-SDR project and allows you to use the RTL-SDR dongle to tune in arbitrary stations either with a simple web application running on a built-in server, or programmatically with Python or […]

30C3 video: Monitoring the Spectrum – Building Your Own Distributed RF Scanner Array

At the recent 30C3 conference in Hamburg, Germany, Andrew Reiter outlined his efforts in using inexpensive RTL-SDR dongles to build a distributed RF scanner array for monitoring and spectrum mapping. Software-Defined Radio (SDR) has increased in popularity in recent years due to the decrease in hardware costs and increase in processing power. One example of […]

DCC/TAPR video: HackRF – A Low Cost SDR Platform

In this talk from the 2013 Digital Communications Conference (DCC) co-sponsored by the ARRL and TAPR, developer Michael Ossmann discussed the origins and development of the HackRF Jawbreaker SDR transceiver. This is Michael’s first talk at an amateur radio oriented conference.