HV Open is the premier open source software group of the Hudson Valley, formerly known as the Mid-Hudson Valley Linux Users Group (MHVLUG) that Sean Dague and others founded in 2003.
MHVLUG made the shift to fully embrace open source beyond just Linux a few years ago and created the reason to change names. Current leadership anchored by Matthias Johnson, Joe Apuzzo and Jack Chastain have done a fantastic job along with Sean by seeking additional presenters of related topics to illustrate how much more widespread open source software has become with languages like Python being one of the most popular for those looking at SDR or IoT applications.
SDR & IoT: Sensing the world around you with open source software
HV Open was interested for HVDN to give a presentation on software defined radio at its monthly meeting held on the grounds at Vassar College in Poughkeepsie, New York. The slides can be found in our presentation repository. The presentation was given by Steve Bossert.
Why open source matters when talking about SDR and IoT?
Amateur radio as a hobby is under immense change due to technology advancements, relevance, use cases and public perception.
The goal of this presentation was to highlight beyond amateur radio where there is innovation and opportunity to converge with other hobby groups and exchange knowledge, inspiration and expertise.
HVDN members create high impact and engaging presentations and this one was no exception. For the 20 or so HV Open supporters present, they were treated to a video based on the often imitated Star Wars opening movie sequence to help set the stage for a great overview followed by a Q&A session.
Beyond what was captured in the presentation, there was a good bit of hardware demonstrated alongside Steve's presentation to help illustrate that an entry into SDR can be done at low cost by way of the popular RTL-SDR V3 USB receiver and the even more "covert" NooElec Nano 3 USB receiver.
For those interested in obtaining an amateur radio license and the ability to transmit with an SDR the Lime SDR Mini or the ADALM Pluto are two popular options.
All four SDR will work with the software Steve covered in his presentation and certain applications can be run not only on a regular computer or laptop, but also a Raspberry Pi or even a small Wi-Fi travel router such as those sold by GL.iNet that run OpenWRT.
|From rear left to right - Zopsc wireless vibration sensor, GL iNet MT-300, AcuRite 02097M|
From front left to right - Lime SDR Mini in custom 3D printed case, NooElec Nano, RTL-SDR V3
With any SDR device, different transmission sources such as common temperature sensors like those sold by AcuRite which mostly transmit in the ISM spectrum around 433 MHz. A different type of sensor presented was by a more obscure vendor named Zopsc and can be used for a variety of security applications.
Using a common USB power bank and external antenna such as a small 433 MHz magnet mount are all that is needed aside from an SDR and travel router to create a very flexible and light weight portable monitoring station for IoT devices.
For those interested in a more complete and "professional looking" implementation of a remotely accessible SDR, Steve showed off his slightly over engineered and re-purposed example of such a device. Inside the blue commercial battery enclosure he sourced from the "maker's crown jewel for parts" of the Hudson Valley called P&T Surplus. Here is a basic block diagram inside this rugged enclosure.
The 12 V to 24 V DC converter is not needed for this all to work nor is the external Ethernet port or PoE splitter but were added for flexibility to use the remote SDR setup to provide power and connectivity for longer range Wi-Fi with a Ubiquiti Bullet M2 for mesh networking applications.
Power from the high capacity battery can run the basic implementation of the travel router and SDR for over seven days continually or for a few days less when using the "power over ethernet" mesh device.
All the cabling is interchangeable for easy application changes ranging from standard spade clips for DC power connections to the Ethernet and SMA antenna ports.
Using a remote SDR for IoT sensing
It is very easy to install rtl_tcp or rtl_433 onto the OpenWRT enabled router to share what is received by the SDR with any computing device that has Wi-Fi access.
A benefit of a remote SDR is no loss of signal or more convenient placement of your IoT sensing antenna and then be able to capture, analyze and use the signals from the comfort of your kitchen table or office with no wires hanging around to trip over.
Open Source Software & SDR
The many options explored in the presentation for software are tough to capture in detail via this article summarizing the presentation, but should act as inspiration to explore Git in more depth as well as other open source software repositories as well as future articles on HVDN or presentations.
There is much to experiment with from both the hardware and software perspectives involving software defined radio and the internet of things and this presentation merely scratched the surface.
Terms like machine learning and artificial intelligence are already catching on within the SDR community as well as in IoT or open source as touched on in Steve's presentation.
Interested in customized presentations for your group?
Since the inception of HVDN in 2017, we have supported the the Mid Hudson Valley Astronomical Society, the Squidwrench maker community, Trenton Computer Festival and HV Open with engaging presentations to spread the word about the convergence of amateur radio with other hobby groups.
If you are interested in inviting in HVDN to give a presentation in the general Hudson Valley region of New York or slightly outside our beautiful borders, HVDN leadership can be contacted through the HVDN Notebook blog as well as via our contact page on the HVDN.org website.
SDR & IoT: Sensing the world around you with open source software presentation