Wavelet Lab is looking to make software-defined radio more accessible, using a compact M.2 SDR module dubbed the uSDR alongside a WebUSB-connected browser-based software bundle with some impressive collaboration features.
“uSDR is an embedded software-defined radio board that targets ease of use and collaboration,” Boston-based Wavelet Lab says of its upcoming offering. “It incorporates WebUSB technology, which enables full functionality in the Chrome browser under Linux, Windows, MacOS, and Android, all without requiring specific drivers or software. The uSDR web platform makes software-defined radio accessible to everyone, providing an easy starting point from which to learn and prototype.”
The compact M.2 2230-format uSDR – not to be confused with the unrelated uSDR software package – connects to a host over USB and offers a 300-3,700MHz range, 30.72 mega-samples per second (Msps) resolution, and a single full-duplex receive-transmit channel. A Lime Micro LMS6002D field-programmable radio-frequency chip provides the radio portion of the equation, with an AMD Xilinx Artix-7 hosting glue logic.
The hardware connects to WebSDR, Wavelet Lab’s browser-based software package. In addition to the usual functions you’d expect, WebSDR includes a range of collaboration functions — from being able to easily share IQ recordings with others to offering the ability for multiple users to work with a single physical uSDR.
More details are available on the uSDR Crowd Supply campaign page.
Wireless communications and software-defined radio engineer Marc Lichtman and colleagues have been working on similarly web-based toolkit for signal analysis, processing, and sharing, dubbed IQEngine – with the same goal of making SDR projects more accessible to a wider audience.
The project was begun by Marc after students of an SDR-focused course had difficulty getting existing desktop software to play nicely with their particular operating systems and hardware setups. Prototyped during a one-week hackathon at Microsoft, the first fully-functional open-source version of the platform was released earlier this year.
IQEngine, its maintainers say, is ideal for analysing and organising recordings, and for testing signal detection and classification algorithms – with less of the configuration issues which can plague rival applications. The software also includes integrated sharing functionality, allowing individual recordings or full datasets to be quickly shared – even if the recipient doesn’t have IQEngine installed themselves. In addition to cloud support, it’s possible to run IQEngine locally for working on more sensitive data.
IQEngine is available to use on the project website now with no local installation required, thanks to hosting by GNU Radio, while its source code is published to GitHub under the permissive MIT licence.
Daniela de Paulis, Artist in Residence at the SETI Institute and the Green Bank Observatory, has lead a project to see what it would really be like to receive a message from another world – transmitting a simulated alien communication from a very real radio in orbit around Mars.
“Throughout history, humanity has searched for meaning in powerful and transformative phenomena,” Daniela explains by way of background to the A Sign in Space project. “Receiving a message from an extraterrestrial civilization would be a profoundly transformational experience for all humankind. A Sign in Space offers the unprecedented opportunity to tangibly rehearse and prepare for this scenario through global collaboration, fostering an open-ended search for meaning across all cultures and disciplines.”
“This experiment is an opportunity for the world to learn how the SETI community, in all its diversity, will work together to receive, process, analyse, and understand the meaning of a potential extraterrestrial signal,” adds ATA Project Scientist Wael Farah, PhD. “More than astronomy, communicating with ET will require a breadth of knowledge. With ‘A Sign in Space,’ we hope to make the initial steps towards bringing a community together to meet this challenge.”
A recording of the message is available on the project website, with the community invited to attempt their own technical and cultural interpretation of the signal and to submit their findings.
Pseudonymous YouTuber “Tech Minds” also has their eyes to the sky, with a video showcasing how to use SDR++, GPredict, Soundmodem, and Greencube Terminal to receive and decode signals from the GreenCube CubeSat.
“As [radio] amateurs we’ve been given access to a special feature of [the GreenCube] satellite,” Tech Minds explains, “and that’s a digipeater built into the GreenCube’s telecommunications subsystem. What’s interesting is that GreenCube has not been launched into LEO [Low Earth Orbit] like we see with other amateur satellites, but GreenCube has been launched in MEO – Medium Earth Orbit – which provides a larger footprint on the Earth.”
Launched back in July, GreenCube aims to experiment with the cultivation of microgreens in microgravity – though it’s the digipeater, rather than the satellite’s primary experimental payload, which is the focus of Tech Minds’ attention. The video walks through the tracking of the satellite with GPredict, reception of the digipeater’s signal using a software-defined radio and the popular SDR++ software, and processing and decoding via Soundmodem and the GreenCube Terminal package.
Another pseudonymous YouTuber, IMSAI Guy, has published a video on the design and testing of an unusual antenna – shaped like the corner of a cube.
“[I was] talking about antennas the other day and it reminded me about an antenna that I had once that was for receiving cable TV, like microwave cable TV, for free,” IMSAI Guy explains. “I built a little corner antenna that was just a dipole and there was some kind of connector, like an end connector, a BNC or something, I forget what it was, and there’s bent wires, all coat-hanger wires, they were thick, and they actually sat in the corner of a reflector.”
With these memories and a few articles, IMSAI Guy set about building another corner antenna – replacing the aluminium of the original with raw copper PCBs soldered into a right-angled corner. “Then I soldered a little SMA connector just some random distance,” IMSAI Guy says, “I didn’t bother to figure it out I just [did] whatever felt good to me and I stuck it in there.
“As with most things I just want to do it right [now], I say don’t worry about all the math, don’t worry about all that just do it, just try it out, just have fun.”
The full video is available on IMSAI Guy’s YouTube channel now.
Programmer Angelina Tsuboi has released a command-line tool for anyone interested in satellite communications, designed to pull in data from open sources and give you as much information as it can about the satellites of your choice: SatIntel.
“SatIntel is an OSINT [Open-Source Intelligence] tool for satellite reconnaissance made with Golang,” Angelina says of the project, which is itself open source. “The tool can extract satellite telemetry, receive orbital predictions (visual and radio), and parse TLEs [Two-Line Elements].”
The software, which uses a text-based user interface and runs in a terminal, isn’t designed to interface with radio hardware itself. Instead, it pulls down the data required from two online services – Space Track and N2YO – through their application programming interfaces. Angelina has already revealed some planned feature upgrades, too, including improved orbital predictions and an ASCII-art map of satellite positions.
The software and its Go source code are available to download from GitHub under an unspecified open-source license. Angelina has also published a companion article on the concept of “aerospace hacking” through satellite OSINT.
Great Scott Gadgets has announced plans, created in partnership with Amateur Radio Digital Communications (ARDC) and TAPR, to built a tool designed to assist with a wide range of radio projects: the University Radio Test Instrument (URTI).
“We aim to develop an open-source SDR platform with an unparalleled set of radio investigation and experimentation functions in one versatile device,” Great Scott Gadgets’ Elizabeth Hendrex explains. “URTI will offer radio amateurs, researchers, educators, and professionals an affordable, compact RF test tool that could be used in place of multiple expensive pieces of traditional radio test equipment.
“Our goal for URTI is to design a single hardware platform capable of serving as many popular types of one-port or two-port RF test instruments. We plan to build a directional coupler into a wideband, full-duplex SDR platform to enable URTI to function as a: spectrum analyser; vector network analyser; vector signal generator; vector signal analyser; antenna analyser; power meter; frequency counter; full-duplex SDR transceiver.”
The company plans an eight-phase development process, with a view to distributing 50 prototypes of a tethered USB peripheral version and another 50 of a fully self-contained portable version to beta testers. No date has yet been announced, though those interested in the projects can follow its development on the Great Scott Gadgets Lab Notes GitHub repository.
More information is available on Great Scott Gadgets’ website.
Developer Daniel H. has designed a “simple but capable” amplitude modulation (AM) radio transmitter, which requires only a Raspberry Pi Pico development board and a few passive components.
“The Pi [Pico] generates a 1,557kHz PWM [Pulse Width Modulation] signal, which will be the carrier wave. The frequency is not changed, only the pulse width,” Daniel explains. “Then, an audio input is taken in on the right side of the breadboard, which is clamped and slightly loaded so that we don’t get nasty interference. Then, this clean signal is given to the Pico on pin 26. The Pico does pulse width changes according to the signal, and outputs the AM signal on pin 15.”
“The Pi is not able to output enough power to disrupt anything significantly, but with a long enough antenna, will get you in trouble and annoy others. Please use this only for experimental and educational purposes and do NOT use this in a way which might cause any disruption! My antenna for this is barely large enough for half of my room to have reception. Please don’t go much further than that!”
The project’s wiring diagram and source code are available on Daniel’s GitHub repository under the reciprocal GNU Affero General Public Licence 3.
Pseudonymous developer “henningM1r” has published a GNU Radio tool designed to receive and decode DCF77 long-wave time signals via a software-defined radio.
“This is a basic DCF77 receiver for GNU Radio,” henningM1r explains, “containing: signal demodulation and detection of the DCF77 OOK [On-Off Keying] signal with an SDR using GNU Radio (and Python modules); signal demodulation and detection of the DCF77 phase-modulated signal with an SDR using GNU Radio (and Python modules); a simple live decoder of the received OOK bits provided by the GNU Radio DCF77 receiver; a simple live decoder of the received phase-modulated bits provided by the GNU Radio DCF77 receiver; and additional tools for testing the receivers (especially, if no SDR hardware is available) [including] a DCF77 bit encoder, a simulated DCF77 transmitter, [and] a simulated DCF77 channel.”
The software is supplied as four GNU Radio flowgraphs – the simulated transmitter and channel, plus receivers for OOK and phase modulation – along with three Python scripts for decoding and encoding time signals. “An antenna that provides a sufficiently clear DCF77 signal [is required],” henningM1r notes, “e.g. a simple YouLoop loop antenna was used for this project. Indoor reception should probably be possible if you are close enough (<1,000km) to the DCF77 transmitter in Mainflingen, Germany. You should mount the antenna close to a window or outside.”
The software is available on GitHub under the reciprocal GNU General Public Licence 3.
Finally, sad news from RadioStack as the radically-open Maverick-603 software defined radio project is suspended indefinitely – with all crowdfunding backers receiving a full refund in lieu of hardware.
Announced back in September’s OTA newsletter, the Maverick-603 project sought to build an affordable FT8 receiver using an entirely open-source receiver chip built using an open process development kit (PDK). While the project’s crowdfunding campaign successfully reached its goal, though, unspecified logistical issues mean that production will no longer be going ahead.
“The Maverick-603 project has been indefinitely suspended due to unforeseen logistical obstacles. No funds have yet been spent and all backers will receive full refunds,” the RadioStack team announced late last month. “If you backed this project, your refund will be issued within the next week to the credit card you originally used. If the Maverick-603 project is revived, we will post another update. Thank you for your support and patience.”
The full update can be seen on the Maverick-603 Crowd Supply page.