Backers of the LimeSDR Mini 2.0 have started to receive their hardware, following delivery of the first production batch – with enough to fulfil all existing orders and more.
“The first batch of LimeSDR Mini 2.0 boards have been manufactured, tested, and delivered to our UK headquarters,” Lime Micro’s Andrew Back announced in a campaign update in early January. “We’re delighted to say that there are enough to fill all orders placed to date, both during the campaign and subsequently. In the next few days, we will be packaging boards individually and then shipping them in bulk to Crowd Supply’s warehouse for final delivery to backers.
Backers are expected to receive shipment notifications by the end of the month. All existing orders will be fulfilled from the first batch, with excess stock going up for order on the project’s Crowd Supply page.
The LimeSDR Mini 2.0 is designed to replace the original LimeSDR Mini, offering the same radio specifications but with a larger field-programmable gate array (FPGA) supported by an open-source toolchain – providing a route for users to write custom gateware for everything from digital signal processing to signal detection and filtering on-device.
More information is available on the Crowd Supply campaign page.
Computer engineering student and radio ham Luigi Cruz has successfully ported his CyberEther visualisation project to Apple’s Metal platform, meaning it can now run on iOS devices including the iPad tablet range.
“I ported CyberEther to run on iOS using Apple’s Metal,” Luigi explains, referring to the company’s low-level graphics application programming interface (API). “This demo is streaming I/Q from a LimeSDR connected to the laptop over a Wi-Fi hotspot and doing all the processing and visualisation on the iPhone. It supports any SoapySDR device.”
Support for iOS devices is just the latest string to the CyberEther bow, which aims at extreme portability and which already boasted support for accelerated real-time visualisation on desktop and laptops with Nvidia and AMD graphics cards, Apple’s M1 and M2 processors, and the popular Raspberry Pi range of single-board computers.
Osmocom’s Harald “LaForge” Welte has announced a new “playground” for Digital Enhanced Cordless Telecommunications (DECT) projects, designed to pick up where the abandoned OsmocomDECT project left off.
“Millenia (on the IT timescale) after deDECTed and about a decade after the now abandoned OsmocomDECT project, a group of people in and around Osmocom started to play with DECT again,” Harald explains. “There’s no big plan, or no specific goal, other than getting more hands-on hack value with consumer DECT hardware, at its lowest levels. It started with some innocent ringtone-hacking on a Gigaset C430 by manawyrm, followed by a much appreciated fix for the long-standing bug of Gigaset DECT phones radically over-charging (and eventually killing) their NiMH batteries.
“Initially, this required un-soldering and re-programming the SPI flash. After the debug UART was identified on the two test pads accessible from the battery compartment, manawyrm and tobleminer have figured out how to load code into the processor. Some initial related tools have been created and collected, [which allow you to] execute your own code on the Gigaset C430, C300 and likely many other DECT phones using the Sitel (formerly NatSemi, now Renesas SC14xxx) chipset family.”
More information is available in the Osmocom news post, with interested parties invited to join in the efforts
Radio ham Daniel Estévez has penned an analysis of a signal received from the Lunar Flashlight, a NASA cubesat which recently launched to find water ice on the moon.
“The day after the launch, AMSAT-DL made an IQ recording of the X-band beacon of Lunar Flashlight at 8457.27 MHz with the 20 metre antenna at Bochum observatory,” Daniel writes of the signal used in his analysis. “The modulation used by Lunar Flashlight is PCM/PM/bi-phase-L. This means that the telemetry is Manchester encoded and phase modulated with a residual carrier. The nominal baudrate is probably 48 kbaud. To be more precise, I have measured 48077 baud. Coding is r=1/6 CCSDS Turbo code with 8920 bit frames. This is the CCSDS coding that provides the best Eb/N0 performance.”
As part of the analysis project, Daniel has written and published a GNU Radio flowgraph for decoding the recording – using the gr-dslwp project’s Turbo decoder block and various blocks from the gr-satellites project – along with raster maps designed to find patterns in the decoded data. “APID 1 is specially interesting,” he notes. “It contains Space Packets of four different lengths: 33, 94, 1021, and 2041 (these are the values of the Space Packet data length fields). The packets of different lengths are sent in a regular sequence, as we can see in the raster map. Shorter frames have been padded with zeros at the end, which are shown as a purple colour. First there is a length 33 packet and a length 94 packet. Then there are a bunch of length 2041 packets. Finally there is a length 1021 packet, and the sequence repeats again.”
The European Union Agency for the Space Programme (EUSPA) has announced that Galileo’s High Accuracy Service (HAS) is now live — providing Europe with a sub-25cm horizontal accuracy positioning signal.
“The Galileo High Accuracy Service offers new levels of accuracy to everyone who needs it,” explains Javier Benedicto, director of navigation at the European Space Agency (ESA), “while the Open Service Navigation Message Authentication allows users to authenticate Galileo signals, and therefore supports spoofing detection.”
“The Galileo programme has been performing a long set of HAS testing activities since 2019 leading to the first-ever HAS signal broadcast in May 2021,” adds Javier de Blas, manager of the HAS programme. “Based on the feedback gained during the joint efforts conducted by EUSPA, the European Commission and ESA, with the key support of the European aerospace industry during the testing phase, we were able to publish the first Galileo High Accuracy Service Signal in Space Interface Control Document and introduce the necessary changes to ensure the HAS Initial Service implements the feedback received from the users.”
The service, which provides corrections through both the Galileo satellites and over the internet, is live as of the 24th of January 2023. More information is available in the EUSPA announcement.
A quartet of researchers at ETH Zürich have published a paper detailing how a many-core processor based on the free and open-source RISC-V instruction set architecture (ISA) could help drive more efficient 5G cellular networks through parallelisation.
“5G Radio access network disaggregation and softwarisation pose challenges in terms of computational performance to the processing units,” explain first author Marco Bertuletti and colleagues. “At the physical layer level, the baseband processing computational effort is typically offloaded to specialized hardware accelerators. However, the trend toward software-defined radio-access networks demands flexible, programmable architectures.”
One solution, the team claims, is the use of a scalable processor made of many relatively low-performance but high-efficiency RISC-V cores to parallelise the workload. “Based on the evaluation of the computational effort (in multiply-accumulate operations) required by the PUSCH [Physical Uplink Shared Channel] algorithmic stages, we focus on the parallel implementation of the dominant kernels, namely fast Fourier transform, matrix-matrix multiplication, and matrix decomposition kernels for the solution of linear systems. Our optimized parallel kernels achieve respectively on MemPool and TeraPool speedups of 211, 225, 158, and 762, 880, 722, at high utilization (0.81, 0.89, 0.71, and 0.74, 0.88, 0.71), comparable a single-core serial execution, moving a step closer toward a full-software PUSCH implementation.”
A preprint of the team’s paper is available on Cornell University’s arXiv server under open-access terms.
RTL-SDR has brought our attention to a new release of Viol Tailor’s popular uSDR package, which brings with it a bug fix for LimeSDR users.
In its latest 1.6.0 release, uSDR – designed as a lightweight user interface for various software-defined radio platforms, including the full LimeSDR family – brings with it a bug-fix for an issue when switching between multiple front-ends with LimeSDR devices connected.
Other improvements include more advanced options for playing back I/Q files, a Digital Code Squelch (DCS) decoder, an FM demodulator with inverted audio spectrum, and source code for examples using the software’s support for remote I/Q passband processing via a TCP connection.
The new build also includes the ability to display the spectrum in hold-peak mode, a zoomable and pannable plot, colour customisations, and support for ExtIO DLL files. “Copy ExtIO*.dll and all dependencies to the root folder,” Voil writes, “and have fun!”
The latest version of uSDR is available on SourceForge now.
Popular open-source radio software SDRangel has made the leap to mobile devices with its developer publishing a version on the Google Play store supporting Android smartphones and tablets.
The Android version of SDRangel aims to bring the bulk of the software’s features across from the desktop and laptop variant to smartphones and tablets, including support for all LimeSDR family members. It includes support for time and frequency domain signal analysis with 2D and 3D visualisations, support for interfacing with SDR hardware over a network or directly over a USB On-The-Go (OTG) connection, and features for satellite communications including a satellite tracker, star tracker, built-in maps, and a rotator controller.
At the time of writing, the software supported modems for a range of standards and protocols “including ADS-B (aircraft); AIS (ships); APT (NOAA weather satellites); AM, FM, SSB, M17 and digital voice (ham radio); Broadcast FM and DAB (broadcast radio); NTSC, PAL, DVB-S and DVB-S2 (video); POCSAG (pager); Packet (AX.25) and RS41 (radiosondes).”
The software is available to download on Google Play now, free of charge, supporting Arm-based devices running Android 6 or higher.
Finally, radio ham Kevin “KB9RLW” Loughin has published a design for an Arduino-based voice keyer, translating spoken Morse code into transmittable signals.
“What if someone has a problem with their hands, loss of dexterity with their fingers, injury, stroke or disease that prevents them from using a key or paddles,” Kevin writes. “Why not use the voice? Every CW operator I’ve ever met can speak Morse code. We say the words, ‘Dah’ for a dash, and ‘Dit’ for a dot. The naturally spoken length of each corresponds to the correct ratio in length of the long and short tones of proper code. And speaking is one of the most natural things we do.”
Kevin’s voice keyer is based on that very concept. Built around a low-cost eight-bit Arduino Nano R3 microcontroller, CWvox detects the user’s spoken “Dahs” and “Dits” and activates a key to transmit them as true Morse code over the airwaves. “It’s a simple circuit to put together with commonly available parts,” Kevin notes. “Should be easy for anyone with basic electronic skills to assemble.”