Category: Applications

Using an RTL-SDR to Decode Broadcast FM RDS Data on Android

Over on YouTube Double A Labs has posted a new video demonstrating how to use an RTL-SDR and Android device to receive broadcast FM stations, and to decode any associated RDS data. 

In the video Double A uses the SDR Touch Android app and the Advanced RDS function to show the RDS information. He goes on to explain the various pieces of information RDS data provides including clock time, active RDS groups and alternative frequencies.

Tune broadcast FM radio and decode Radio Data System (RDS) information using your Android phone and an RTL-SDR USB (see parts list below). RDS can include station identification, song name, the current time for a receiver to sync its clock, alternative frequencies the same program is on, and more!

Tuning FM Radio & Decoding RDS Data on ANDROID using RTL-SDR USB

RTL-SDR Virtual Reality Spectrum Display Software Released

Back in September 2021 we posted about Manahiyo's software that allows the RF spectrum and related graphs to be viewed in virtual reality, using a VR headset and an RTL-SDR. Back then the software was only demonstrated on YouTube, but not released.

A few days ago Manahiyo released the VR software on GitHub. The software requires a Oculus/Meta Quest2 VR headset, and the it is able to run directly on the headset's computing hardware. This makes it possible to have the RTL-SDR attached to the headset itself.

RTL-SDR VR Software for Oculus Quest 2

Frugal Radio: Travelling with SDR & Scanner Gear

Over on his YouTube channel Frugal Radio, Rob has uploaded a new video whilst on holiday travelling through the USA. In the video he shows what sort of scanner radios, antennas and SDR gear he carries with him on his travels. His gear includes a Uniden SDS-100 scanner, a BCD325 scanner, a Radio-Tone RT4 internet network radio and of course an RTL-SDR Blog V3 and laptop.

He goes on to demonstrate the hardware in action from his Hotel room, decoding local digital audio.

A peek in Frugal's Travel Bag : SDR & Scanner gear on the road

Lon.TV Demonstrates Decoding Various Digital Signals with RTL-SDR

Tech YouTuber Lon.TV has recently uploaded a video demonstrating how to identify and decode various digital transmissions with an RTL-SDR dongle. In the video he explains how to use VB Cable to pipe audio from SDR# into various decoders, and then goes on to show DMR, APRS, POCSAG, L-Band AERO, FT8, and JS8/JS8CALL all being decoded via an RTL-SDR Blog V3 dongle.

Software Defined Radio Part 2 - Decoding Digital Transmissions with an RTL-SDR USB Radio

SDRSharp Guide V4.2 Released

Paolo Romani (IZ1MLL) has recently released version 4.2 of his SDRSharp PDF Guide. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book in English".

As before the document is a detailed guide about how to use SDRSharp, which is the software provided by Airspy. While intended for Airspy devices, SDRSharp also supports a number of third party SDRs, including the RTL-SDR, and it is the software we recommend starting with when using an RTL-SDR.

Paolo writes:

My new v4.2 SDRsharp PDF is out. The guide is now 139 pages long, and covers all the settings, UI customization, included and third party plugins, and use of some external decoders and software, now with Spyserver integration with Raspberry Pi 3/4, etc etc...

Running GR-GSM and IMSI Catcher on a Raspberry Pi 4 with Dragon OS

DragonOS is a ready to use Ubuntu Linux image that comes preinstalled with multiple SDR software packages. The creator Aaron also runs a YouTube channel showing how to use the various packages installed. 

In his latest video Aaron tests his Pi64 image with GR-GSM and IMSI Catcher running with the GNU Radio 3.10 platform on a Raspberry Pi 4. He tests operation with an RTL-SDR and LimeSDR.

GR-GSM is a GNU Radio based program capable of receiving and analyzing mobile GSM data. We note that it cannot decode actual messages without additional information about the encryption key, but it can be interesting to investigate the metadata. GSM is mostly outdated these days, but still used in some areas by some older phones and devices. IMSI Catcher is a script that will record all detected GSM 'IMSI' numbers received by the mobile tower which can be used to uniquely identify devices.

Short video setting up and testing GR-GSM on DragonOS Pi64 w/ GNU Radio 3.10 and the RTL-SDR. The current DragonOS Pi64 build has GNU Radio 3.8 and all the necessary tools to accomplish what's shown in this video. If you'd like to test the build shown in this video, it's temporarily available here until I finish and put it on Source Forge.

A LimeSDR and DragonOS Focal's Osmo-NITB-Scripts was used to create the GSM900 lab environment. The RTL-SDR was able to see and decode the GSM900 network and although only briefly shown in the video, the IMSI Catcher script works.

Here's the fork used for this video and for testing. There's also a pull request on the main GR-GSM repo for this code to be added.

DragonOS Pi64 Testing GR-GSM + IMSI Catcher w/ GNU Radio 3.10 (RTLSDR, Pi4, LimeSDR, OSMO-NITB)

Lightweight Windows Software uSDR Updated to Version 1.5.0

Since 2021 we've posted about Viol Tailor's "uSDR" (microSDR) software a couple of times. uSDR is a lightweight general purpose multimode program for Windows that supports the RTL-SDR, Airspy, BladeRF, HackRF and LimeSDR radios. The software can be downloaded from SourceForce.

Viol notes that recently the project has been updated to V1.5.0 which brings the following new features and changes.

  • lock device frequency on zoom option
  • keep waterfall history – the very great option, do not lose any rare signals
  •  advanced passband IQ recorder
  • passband IQ TCP server for remote processing, C/C++ client source examples included
  • advanced audio player, auto selectable sample rate, separate left/right channels
  • CTCSS decoder
  • markers import option convenient for merge markers 
  • Ctrl+Shift+Drag Up/Down – change spectrum magnitude offset
  • Ctrl+Shift+Mouse Wheel – change spectrum magnitude range (vertical zoom)
  • Ctrl+Mouse Hover – highlight nearest marker
  • Ctrl+Double Click– tune to highlighted nearest marker
  • band plan visualization, simple text format
  • frontend interface improvements
  • GUI improvements
  • spectrum and waterfall popup menus improvements
  • a lot of bug fixes
uSDR aka microSDR. A lightweight SDR receiver program from Windows.

Skies-ADSB: A Browser Based 3D Aircraft Tracker with RTL-SDR ADS-B Receiver

Thank you to Don for submitting news about the release of his new software titled "Skies-ADSB". Skies-ADSB is a browser based app that provides a 3D view of the air traffic around your area. The software can be served on a local networked Raspberry Pi, with ADS-B data being provided by an RTL-SDR connected to the Pi.

skies-adsb is a virtual plane spotting progressive web app (PWA) / virtual aquarium (with aircraft instead of fish) / interactive real-time simulation.

Aircraft are tracked via unfiltered ADS-B transponder data in real-time and rendered in 3D.

The ADS-B data source is meant to be a RTL-SDR receiver connected to a Raspberry Pi running on your home network.

Flight status data is provided by the FlightAware AeroAPI v2.

The aircraft photos are provided by