Tagged: rtl-sdr

Decoding Meshtastic in Realtime with an RTL-SDR and GNU Radio

Over on his YouTube channel, Aaron, creator of DragonOS and WarDragon has uploaded a video showing how it is possible to decode Meshtastic with an RTL-SDR and GNU Radio project called Meshtastic_SDR

If you weren't aware of it, Meshtastic is software that enables off-grid mesh network based communications and can run on cheap LoRa hardware. The mesh based nature of the system means that communications can be received over long distances, without any infrastructure, as long as there are sufficient Meshtastic nodes in an area that are able to route the message to the destination node. One example application of Meshtastic is to use it as a mesh-based text messaging system. This might be useful for teams of hikers, pilots, or skiiers who operate in remote areas without cell phone coverage.

In the video, Aaron shows how to install the Meshtastic GNU Radio software on DragonOS (Linux), and how to run the GNU Radio flowgraph and Python decoder script. Later in the video Aaron shows some test text messages being received by the software.

The Meshtastic_SDR project can also be used to transmit Meshtastic messages with an appropriate TX-capable SDR.

WarDragon Real-Time Decoding Meshtastic w/ GNU Radio & SDR (RTLSDR v3)

Artemis 4 Released: Offline Signal Identification Database

Back in 2019 we posted about the release of Artemis 3, an open-source multi-platform program that makes searching through the Signal Identification Wiki offline possible and easy to do.

Recently Artemis 4 has been released which is an entire rewrite of the code, resulting in some substantial improvements, and paving the way for future features like machine learning based identification. Author Marco Dalla Tiezza writes:

  • Artemis was initially designed to provide an offline solution for consulting the library of signals provided by the community on sigidwiki, but the database was formerly a simple .csv with all its limitations. Now the database is a proper relational sqlite which is much easier handled and offers many other possibilities like: additional fields (for example, each frequency of a signal can contain a description and this is true for every single parameter), faster db operations (for example, filtering signals is done by a simple query), increased extensibility due to the fact that new fields/parameters can be introduced in the future or by the user itself.
  • The only searchable database with Artemis 3 was the Sigid wiki database.Now, with Artemis 4, users can create their own custom databases, enter an arbitrary number of signals and parameters, attach documents or any useful information, and export it by sharing it with their friends.
  • The documentation has been completely revised to be as clear as possible and to be able to take the user from installation to advanced use of the program by giving instructions on how they can contribute to the project. DOCUMENTATION
  • As usual, the program provides a real-time interface to be able to track space weather in near real-time, but now this module is more focused on RF propagation such as meteor scatter, EME, sporadic E, aurora spots, DRAP, aurora forecasts and many more (we are actively adding useful descriptors).
  • Artemis 4 now relies on the PySide 6 graphics framework, which not only allows for a modern and newer, user-customizable GUI but also allows for less use of third-party libraries to run the program.
  • Given the flexibility and especially the modularity of the new software, it is very likely that signal analysis functions will be introduced in the future (such as automatic recognition of signals via machine learning/neural network or simpler ones like FFT for obtaining ACF from an audio file, etc.)
  • The homepage of the project (https://www.aresvalley.com) as been updated as well and there you can see some screenshots or directly download the software to give it a try.

If you weren't aware, the Signal Identification Wiki (sigidwiki) is our sister site, which we started a few years ago to collect and catalog various types of signals that an SDR user might see and hear on the airwaves. The idea is that a user could search the database to learn about and identify unknown signals. Over time it has grown significantly, now over 500 known signals with both waterfall images and sound samples available in the database. We have since handed over the operation of the Wiki to the community, with Carl Colena taking on the lead.

Artemis 4 Screenshot

SignalsEverywhere: Build an RTL-SDR Based OP25 Radio Scanner with a Mobile Control Head Android App

Welcome back to Sarah from the SignalsEverywhere YouTube channel who has recently returned to producing videos from a hiatus. In her latest video, Sarah shows off her new OP25 Mobile Control Head Android App which allows you to implement a full P25 digital radio scanner at a fraction of the cost of a commercial digital scanner. In the past, Sarah had released a similar application written for the Raspberry Pi but has decided to shift her focus to writing an equivalent Android app that is less clunky and can be deployed for a lower cost. 

The app controls and displays information from the OP25 software that runs on a Raspberry Pi with RTL-SDR connected. It works by using a server application on the Raspberry Pi that manipulates the OP25 instance and its configuration files.

Sarah writes:

The application is a wrapper for OP25 that uses a raspberry pi and an android device to provide users with a mobile control head for their OP25 P25 scanner setup. Currently it's just a basic application but I'll be adding features like automatic site switching, etc.

OP25MCH: https://github.com/SarahRoseLives/OP25MCH

There is also a separate application I call the OP25Display which is just a display for a users existing OP25 instance.

OP25Display: https://github.com/SarahRoseLives/op25display

Build Your Own Digital Radio Scanner With OP25 Mobile Control Head App

A 3D Printed Enclosure with USB Hub for RTL-SDR Blog Units

Over on Hackaday, we've seen a post about Jay Doscher's clever 3D printed enclosure that can hold two RTL-SDR Blog V4 units and a USB hub. The enclosure is designed to make it easy to take the two units mobile, and the USB hub inside means that only one USB connection is required to run the two units.

Jay has also thought about cooling, allowing for space between the two dongles, and adding vent holes. He has also ensured that the SMA ports on the dongles are protected while allowing space to hand-tighten the connectors.

Jay writes that he has tested his enclosure with RTL-SDR Blog V4 units, but given that the dimensions of the V3 (and V2) are the same, it will work for those units too.

A 3D Printed RTL-SDR Blog Enclosure with USB Hub
A 3D Printed RTL-SDR Blog Enclosure with USB Hub

uSDR Software Updated to V1.7.0

Thank you to Viol for writing in and letting us know that his uSDR software has recently been updated to V1.7.0. The uSDR software (not to be confused with the unrelated uSDR hardware) is a lightweight general-purpose multimode program for Windows that supports the RTL-SDR, Airspy, BladeRF, HackRF, LimeSDR, and other SDR radios.

Viol highlights the latest features added in the 1.7.0 update below:

  • Fobos SDR frontend native support, the very new SDR from RigExpert
  • bladeRF API v2.5.0 support, oversampling mode up to 122.88 MHz sample rate (do not forget to update FX3 firmware)
  • advanced IQ playback mode, precise timing and streaming
  • improved DSP routines and memory management, minimized CPU load
  • excellent ruler tool for spectrum frequency and amplitude measurements
uSDR Updated to Version 1.7.0. Images shows FobosSDR support.
uSDR Updated to Version 1.7.0. Images shows FobosSDR support.

YouTube Video Series on Iridium Satellite Decoding with an Airspy, RTL-SDR Blog Patch Antenna and DragonOS

Over on his YouTube channel, Rob VK8FOES has started a new video series about Iridium Satellite Decoding. Iridium is a constellation of low-earth orbiting satellites that provide voice and data services. Iridium was first decoded with low cost hardware by security researchers back in 2016 as mentioned in this previous post. Being unencrypted it is possible to intercept private text and voice communications.

Rob's video is part of a series, and so far only part one has been uploaded. The first video outlines the hardware and software requirements for Iridium decoding and demonstrates the gr-iridium software. An Airspy and RTL-SDR Blog Patch Antenna are used for the hardware, and the software runs on DragonOS.

Rob writes that in part two he will demonstrate the use of iridium-toolkit, which can be used to extract data and recordings from the Iridium data provided from gr-iridium.

Be sure to subscribe to his YouTube channel so that you are notified when part two is released.

Iridium Satellite Decoding Part 1: The Tutorial That Goes Over Your Head, Literally!

DeepRad: Upcoming Modular RTL-SDR System to be CrowdFunded

The company "DeepSea Developments" have recently released news about their upcoming crowdfunding campaign for their 'DeepRad' modular RTL-SDR system. The goal of DeepRad appears to be a modular RTL-SDR that can easily be used as a module on a 'motherboard' PCB of your own design.

DeepRad is currently in the 'Coming Soon' stage on CrowdSupply, and will probably be released for crowdfunding in the next few months.

DeepRad is a modular version of the RTL-SDR, a product beloved by radio enthusiasts. However, DeepRad offers distinct advantages. Its modularity makes integration far simpler, side-stepping the complexities of designing an RTL-SDR from scratch (such as RF considerations and chip stocking issues). DeepRad is a versatile option for integrating many different radio functions into whatever projects you’re working on today.

We want the community to create their own "motherboards" with 1, 3, or as many as 20 DeepRad modules to bring new applications to life. There are three versions of DeepRad we’ll be focusing on for this campaign:

  • DeepRad Module: The bare DeepRad module (no motherboard). The user has to develop a board to use it.
  • DeepRad Single: A single DeepRad module with a motherboard. It has USB Type-C and an antenna connection. It can be used as your regular RTL-SDR with USB.
  • DeepRad Quad: A motherboard with 4 DeepRad modules integrated via a USB hub with a USB Type-A connector.
The DeepRad Quad Motherboard with Four DeepRad Modules

QCSuper: Capture 2G/3G/4G/5G Radio Frames with Qualcomm Phones

In the past, we've shown how it's possible to use RTL-SDRs or other SDR devices together with the Airprobe software to analyze data from 2G GSM mobile phones and towers. (Note that it's not possible to listen in on conversations or read SMS data unless you have the encryption code for the recipient phone. This is only capable of showing cell tower basestation telemetry for example).

While not directly related to SDR, readers might be interested to know that a new piece of software called QCSuper has been released which enables similar analysis capabilities for 2G/3G/4G/5G signals through the use of Qualcomm-based phones and modem hardware. To use it you will need a rooted Android phone. The software accesses a diagnostics mode available in Qualcomm devices and makes the data available for view on Wireshark.

[Also seen on Hackaday]

QCSuper Screenshot
QCSuper Screenshot