Category: Applications

SignalsEverywhere: Monitoring Itron ERT Smart Meters on Android

Over on her YouTube channel SignalsEverywhere, Sarah has uploaded her latest video showing how it is possible to monitor Itron ERT smart meters on an Android device.  Smart meters are used to wirelessly monitor the usage of residential utilities such as water, gas, and electricity. With an RTL-SDR and some decoding software, it is possible to monitor the data coming from your own and your neighbours meters (at least for certain brands of meter).

In her video, Sarah shows how she compiled the rtl_amr decoder software for Android, and created her own Android app called "AndAMR" for displaying the data decoded by rtl_amr. The rest of the video shows how to set up and use the app.

Monitoring Itron ERT Smart Meters on Android?!

Tech Minds: Testing an Inmarsat L-Band Helix for Offset Satellite Dishes

In his latest video, Matt from the TechMinds YouTube channel tests out an LHCP L-band helix feed designed for receiving Inmarsat satellites. Matt pairs the feed with an 85cm satellite dish, an L-band LNA, and an Airspy Mini.

The L-band helix feed comes from a small German engineering company called nolle.engineering. The feed is priced at 94.70 Euros (incl. VAT) (~$102 USD), plus shipping costs. It is a passive antenna so it needs to be combined with an LNA to be usable with a typical SDR.

In the video Matt shows that the reception with the LHCP helix + dish setup is better than expected. He also compares it to a previous test he did with a longer RHCP helix antenna also produced by nolle.engineering. The RHCP antenna is used to be used without a dish, however, as expected the SNR is less than the dish + small LHCP feed setup. Matt then shows some Inmarsat signals being decoded including STD-C and Aero voice.

This L Band Helix Antenna Gives Amazing Performance

SDR# Big Guide Book: 2024 Edition Released

Paolo Romani (IZ1MLL) has recently released the 2024 version of his SDR# Big Book. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book" and choose your language. (At the time of this post only English and Italian are available in the 2024 edition, but multiple languages are available for the older guides).

Paolo writes that the book has been updated for the latest SDR# v1920 version, and now the editions will be labelled by date, instead of version number. He also writes that page 25 of the big book now includes information about the differences between RTL-SDR Blog V3 and V4 dongles. 

The Big Book of SDR# Studio 2024 Edition

Tech Minds: Testing the NooElec FlyCatcher RTL-SDR ADS-B+UAT Raspberry Pi Hat

Over on YouTube Matt from the Tech Minds YouTube channel has tested out NooElec's new 'FlyCatcher', which is an RTl-SDR ADS-B hat for the Raspberry Pi. The FlyCatcher has two RTL-SDRs built into it, each with it's own LNA and SAW filter. One SAW filter is tuned for 978 MHz UAT, and the other for 1090 MHz ADS-B.

The device also has buttons that allow you to bypass the LNA stage, and just use filtering, in case you have an external LNA. They appear to be using the Qorvo TQL9063 LNA chip, which has a built-in bypass.

In the video Matt tests out the FlyCatcher, but only on 1090 MHz as 978 MHz UAT is not used in his country. He shows how to set up the software on the Raspberry Pi and then shows some results.

Easily Create Your Own Aircraft Virtual Radar Using The NooElec FlyCatcher Pi Hat

Tech Minds: Using the RK888 MK2 to Receive the Entire HF Band

In one of his latest videos Matt from the Tech Minds YouTube channel tests out the RX888 MK2 software defined radio at HF frequencies. Matt notes that while the bandwidth of this SDR is limited to 10 MHz at VHF/UHF, you can actually use it in direct sampling mode to achieve a massive bandwidth of 64 MHz, allowing you to receive the entire HF band at simultaneously.  

In his video, Matt uses SDR-Console V3 and he shows the entire HF band being received at once. He also shows the SDR-Console V3 matrix bands organizer, which allows you to create multiple windows of zoomed-in spectrum. That combined with the multi-receiver feature could allow you to have multiple audio outputs for digital decoding across the HF band.

Amazing! ALL HF Bands at the SAME time with the RX888 Mk2

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)

An Atmega328 + SI5351 Based WSPR Beacon

Thank you to Ihar Yatsevich for writing in and sharing with us his open-source WSPR beacon project. The WSPR beacon consists of a custom PCB with ATMega328 microcontroller, GPS module, single transistor amplifier, and Si5351 with TCXO.

The result is a very simple, portable WSPR beacon that can be heard all over the world. However, it appears that no band filters are built into this, so you will need to add a bandpass filter for the WSPR band that you are using.

WSPR (Weak Signal Propagation Reporter) (pronounced "whisper") is an amateur radio digital HF mode designed to be decodable even if the signal is received with very low power. Because of this design, even low-power transmitters can be received from all over the world. It can also be used to help determine HF radio propagation conditions as WSPR reception reports are typically automatically uploaded to wsprnet.

If you are interested, Ihar has written about his project in more detail over on Reddit

Ihar's Microcontroller Based WSPR Beacon
Ihar's Microcontroller Based WSPR Beacon

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