Remote SDR V2 is software that allows you to easily remotely access either a PlutoSDR, HackRF or RTL-SDR software defined radio. It was originally designed to be used with the amateur radio QO-100 satellite, but version 2.0 includes multiple demodulation modes, NBFM/SSB transmission capability, CTCSS and DTMF encoders, modulation compression and a programmable frequency shift for relays.
MMDVM is firmware that normally runs on an ARM microcontroller board such as the Arduino Due, and is designed to be interfaced with hardware radios via the microcontrollers built in ADC and DAC hardware.
In order to use an SDR instead of physical hardware radios, Adrian's article describes how a fork of MMDVM called MMDVM-SDR is used in his system as this allows the code to run on a normal Linux computer with an SDR. GNU Radio running on Adrian's own QRadioLink software is then used to create software ADC/DAC interfaces for the SDR and MMDVM-SDR to interface with, as well as providing a user interface.
Over on YouTube Aaron has uploaded a video showing how he is using the SDR4Space.lite package in DragonOS to do some interesting experiments with automated spectrum analysis using a PlutoSDR or RTL-SDR. As a reminder, Aaron is responsible for DragonOS which is a Linux OS with many SDR software programs preinstalled (including SDR4Space.lite).
Any of these scripts can be modified, new ones can be built, and cron jobs or other scripts could call upon them as needed. I hope to do more videos once I figure out how to take the data and put it into some sort of database.
DragonOS Focal Automate Spectrum Analysis + IQ recording w/ SDR4space.lite (RTLSDR, PlutoSDR) part 1
The "Pluto Plus" (aka Pluto+) is an unofficial and upgraded version of the Analog Devices ADALM Pluto SDR. It is currently available on Aliexpress and Banggood stores. In his latest video Tech Minds reviews a Pluto+ SDR that he has received, noting that it has all of the features that should have been in the original Adalm PlutoSDR.
He notes that the PlutoSDR+ has various improvements over the PlutoSDR such as that it comes in a metal enclosure, has four SMA connections (2x TX, 2x TX), a Gigabit Ethernet connection, a microSD slot, external clock input, 0.5PPM TCXO, fine tunable clock via resistor, a PTT key port and a DFU key.
In the video he goes on to show how to set up the PlutoSDR+ before testing it out on a QO-100 satellite setup, noting that it works perfectly and without any signal drift noticed.
In his latest YouTube video Tech Minds explains and demonstrates Remote SDR V2, which is software that allows you to easily remotely access either a PlutoSDR, HackRF or RTL-SDR software defined radio. It is designed to be used with the amateur radio QO-100 satellite, but version 2.0 now include multiple demodulation modes, NBFM/SSB transmission capability, CTCSS and DTMF encoders, modulation compression and a programmable frequency shift for relays.
In his video Tech Minds shows how to install Remote SDR V2 onto an Orange Pi via the SD card image, how to access the web interface, and how to access and use the connected SDR.
Remote SDR V2 with Orange Pi and Transmit Capable
We note that the code is designed to be run on Orange Pi boards, which are low cost single board computers similar to Raspberry Pi's. However over on Twitter @devnulling has indicated that his own fork of the code should run on x86 systems. Aaron @cemaxecuter is also working on including it into a DragonOS release.
The image below demonstrates a typical Remote SDR V2 transceiver setup with two HackRFs.
Back in March last year we first posted about the release of SATSAGEN, and program by Alberto (IU1KVL) that allowed the PlutoSDR to work as a spectrum analyzer. SATSAGEN has recently been updated to version 0.5, and it now supports the RTL-SDR, HackRF and Simple Spectrum Analyzer hardware as well.
Spectrum analyzer software allows you to monitor spectrum activity over a bandwidth much larger than what your SDR supports. It works by rapidly sweeping over multiple frequencies and stitching the spectrum slices together.
Some highlights of the new features include:
Simple Spectrum Analyzer series like NWT4000, D6 JTGP-1033, Simple Spectrum Analyzer, and so on.
Video trigger, real-time trigger, and fast-cycle feature
ADALM-PLUTO custom gain table and Extended linearization table for all devices
On Wednesday Nov 11 Noon Pacific time, Hackaday will hold a hack chat (group text chat session) with Marc Lictman, author of the free online book "PySDR: A Guide to SDR and DSP using Python". We posted about the release of this book last month, noting that it is probably one of the best books in terms of explaining DSP fundamental concepts in an easy to understand way. Hackaday write:
“Revolution” is a term thrown about with a lot less care than it probably should be, especially in fields like electronics. It’s understandable, though — the changes to society that have resulted from the “Transistor Revolution” or the “PC Revolution” or more recently, the “AI Revolution” have been transformative, often for good and sometimes for ill. The common thread, though, is that once these revolutions came about, nothing was ever the same afterward.
Such is the case with software-defined radio (SDR) and digital signal processing (DSP). These two related fields may not seem as transformative as some of the other electronic revolutions, but when you think about it, they really have transformed the world of radio communications. SDR means that complex radio transmitters and receivers, no longer have to be implemented strictly in hardware as a collection of filters, mixers, detectors, and amplifiers; instead, they can be reduced to a series of algorithms running on a computer.
Teamed with DSP, SDR has resulted in massive shifts in the RF field, with powerful, high-bandwidth radio links being built into devices almost as an afterthought. But the concepts can be difficult to wrap one’s head around, at least when digging beyond the basics and really trying to learn how SDR and DSP work. Thankfully, Dr. Marc Lichtman, an Adjunct Professor at the University of Maryland, literally wrote the book on the subject. “PySDR: A Guide to SDR and DSP using Python” is a fantastic introduction to SDR and DSP that’s geared toward those looking to learn how to put SDR and DSP to work in practical systems. Dr. Lichtman will stop by the Hack Chat to talk about his textbook, to answer your questions on how best to learn about SDR and DSP, and to discuss what the next steps are once you conquer the basics.
Dr. Marc Lichtman has recently released his free online PySDR guide to Digital Signal Processing (DSP) explained with the help of software defined radio and Python code. Over the years we've seen numerous SDR & DSP courses come out, some requiring payment and some free. We note that this guide is completely free, and appears to be one of the better if not the best guide in terms of explaining DSP fundamental concepts in an easy to understand way. A lot of visualizations and animations are used which really help anyone new to the subject.
While the explanations are very good, please note that this is still a technical University level guide intended for Computer Science or Engineering students, so prerequisite knowledge is required. Dr. Marc recommends it for someone who is:
Interested in using SDRs to do cool stuff
Good with Python
Relatively new to DSP, wireless communications, and SDR
A visual learner, preferring animations over equations
Better at understanding equations after learning the concepts
Looking for concise explanations, not a 1000 page textbook
The SDR hardware used in the book examples is the PlutoSDR which is a fairly low cost SDR intended for use by students. However, the PlutoSDR isn't required as most of the code examples use generated data.