Software Defined Radio (SDR) category

Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.

Experimenting with software defined radio used to be expensive, but now it is cheap. Nowadays it is very cheap to start experimenting with SDR. Most receivers use a variable-frequency oscillator, mixer, and filter to tune the desired signal to a common intermediate frequency or baseband, where it is then sampled by the analog-to-digital converter. Cheapest wide receiving range well working device is to use suitable DVB-T receiver stick (10-20 Euros/Dollars) and suitable software (very many alternatives, for example SDRsharp and Gnu Radio).

My article Software defined radio with USB DVB-T stick started the long list of SDR related postings. The newest postings now are Filter measurements with RF noise source and Antenna measurements with RF noise source.

432 Comments

  1. Tomi Engdahl says:

    Shmoocon: Delightful Doppler Direction Finding With Software Defined Radio
    https://hackaday.com/2018/01/23/shmoocon-delightful-doppler-direction-finding-with-software-defined-radio/

    When it comes to finding what direction a radio signal is coming from, the best and cheapest way to accomplish the task is usually a Yagi and getting dizzy. There are other methods, and at Shmoocon this last weekend, [Michael Ossmann] and [Schuyler St. Leger] demonstrated pseudo-doppler direction finding using cheap, off-the-shelf software defined radio hardware.

    The hardware for this build is, of course, the HackRF, but this pseudo-doppler requires antenna switching. That means length-matched antennas, and switching antennas without interrupts or other CPU delays. This required an add-on board for the HackRF dubbed the Opera Cake. This board is effectively an eight-input antenna switcher using the state configurable timer found in the LPC43xx found on the HackRF.

    Reply
  2. Tomi Engdahl says:

    SDR’s Hard Side Shown in DARPA Hackfest
    https://www.eetimes.com/author.asp?section_id=36&doc_id=1333114

    A DARPA program manager shares experiences from a hackfest he hosted on software-defined radio (SDR) and drones in Silicon Valley last fall.

    When I was running the GNU Radio Project before my current gig at Defense Advanced Research Projects Agency (DARPA) began in 2016, I found it useful to bring the core developers from around the world together for a few days for what we referred to as our “hackfests.” These gatherings gave us an opportunity to break away from our offices and day-to-day responsibilities to work out some of the larger technical problems we were facing in the Project.

    During these few-times-a-year hackfests, we worked crazy-long hours, lived on fast food, and de-prioritized sleep– an energizing combination that fostered collaboration and focused our attentions in uniquely fruitful ways. As a result of some of our hackfests, core and prominent features were created that still reside inside GNU Radio today.

    Reply
  3. Tomi Engdahl says:

    The XTRX: An Embedded SDR
    https://blog.hackster.io/the-xtrx-an-embedded-sdr-bbd840e27784

    Most people getting started with Software Defined Radios (SDRs) will pick up a cheap RTL2832U and R820T2 based RTL-SDR USB stick on Amazon for under $20. There are literally dozens of free and open-source software packages

    The Fairwaves XTRX, now on Crowd Supply, is not one of these sticks. It’s something rather different

    The XTRX is a compact Mini PCIe card SDR based around the Lime Microsystems LMS7002M FPRF. It has 2× 2 MIMO and has a tuning range of 10 MHz — 3.7 GHz, down to 100 kHz with some degradation, with a sample rate of up to 120 MSPS. It has a built-in GPSDO and an onboard FPGA, a Xilinx Artix 7 35T, which can be used to accelerate DSP tasks.

    The XTRX is part of a growing trend right now of productization of maker hardware. We’ve seen this before with things like the Raspberry Pi Compute Module.

    This is an SDR designed to be a component, a black box to be slotted into a bigger build,

    Also available is XTRX PCIe Octopack, a full sized PCIe card loaded with eight XTRX boards, and a special board for synchronising all eight XTRX boards.

    With synchronized clocks, multiple XTRX boards can collectively monitor very large chunks of the RF spectrum—eight synchronised XTRX boards can monitor nearly a full 1 GHz of bandwidth.

    Reply
  4. Tomi Engdahl says:

    A Classy SDR Chip, Decapped
    https://hackaday.com/2018/05/27/a-classy-sdr-chip-decapped/

    If you are a regular searcher for exotic parts among the virtual pages of semiconductor supplies catalogs, you will have probably noticed that for a given function it is most often the part bearing the Analog Devices logo that is the most interesting. It may have more functionality, perhaps it will be of a higher specification, and it will certainly have a much higher price. [Zeptobars] has decapped and analyzed an AD chip that holds all three of those honors, the AD9361 SDR transceiver.

    It’s placed under a slightly inflammatory title, “when microchips are more profitable than drugs“, but does make a good job of answering why a semiconductor device at the very cutting edge of what is possible at the time of release can be so expensive. The AD9361 is an all-in-one SDR transceiver with an astonishing bandwidth, and as such was a particularly special device when it reached the market in 2013.

    The financial analysis puts Analog Devices’s gross profit at about $103 of the $275 retail purchase price of an AD9361. The biggest slice at $105 goes to the distributor, and surprisingly the R&D and manufacturing costs are not as large as you might expect.

    Analog Devices AD9361 – when microchips are more profitable than drugs
    https://zeptobars.com/en/read/AD9361-SDR-Analog-Devices-DAC-ADC-65nm

    When Analog Devices released their SDR transciever AD9361 in 2013 – it was a revolution in digital radio. SDR’s were there before, but only now you can have it all: 2 channels for TX and RX with onboard 12-bit DAC/ADCs with 56MHz of RF simultanious bandwidth, local oscillators, mixers and LNA – all working in the range from 70 (TX from 47) to 6000Mhz. Using AD9361 out of the box one could implement almost any useful digital radio, with the rare exceptions of UWB and 60GHz. You only need to add data source/sink (which is still often an FPGA), external filters and PA if your task requires it.

    After decapsulation we see 4336×4730 µm 65nm die.

    Let’s do some rough math
    Die size is ~ 21,12mm², 300mm wafer (65nm is only on 300mm ones) has approximately 65’000 mm² of usable area. So given conservative 50% yield we are getting 1538 good dies per wafer. Given wafer cost of 1600$ – manufacturing cost of each good die is ~1.04$.

    NRE – 2 mask sets (400K$ each) and some tooling – will take 1mil$ total. If we conservatively estimate total manufacturing volume of 1000 wafers – NRE would add 0.64$ per good die.

    Retail price of AD9361 at distributes is 275$, volume price from manufacturer is 175$.

    That is quite an impressive added value! For 1,68$ of manufacturing cost we are getting 173,32$ of added value!

    Reply
  5. Tomi Engdahl says:

    BladeRF 2.0 Micro is Smaller, More Powerful
    https://hackaday.com/2018/08/30/bladerf-2-0-micro-is-smaller-more-powerful/

    When it was launched in 2013, the BladeRF was one of the most powerful of the new generation of Software Defined Radios. Now, Nuand, the producers of the BladeRF are looking to up the ante again with the BladeRF 2.0 Micro. This new version has a huge list of changes and improvements, including a more bad-ass FPGA processor and support for receiving and transmitting from 47 MHz all the way up to 6 GHz, with 2x MIMO support and an impressive 56 Mhz of bandwidth. It also retains backwards compatibility with the original BladeRF, meaning that any software written to support it (which most SDR packages do) will just work with the new device.

    At the heart of the BladeRF 2.0 Micro is an Altera Cyclone V FPGA. Nuand are producing two versions of the Micro: the $480 xA4 uses the 49KLE Cyclone V FPGA, while the $720 XA9 is built around the 301KLE Cyclone V FPGA.

    https://www.nuand.com/product/bladerf-xa4/

    Reply
  6. Tomi Engdahl says:

    Using a HackRF One PortaPack as a Mag Stripe Reader and Replayer
    https://blog.hackster.io/using-a-hackrf-one-portapack-as-a-mag-stripe-reader-and-replayer-36690c93772a

    A HackRF One software-defined radio (SDR) will let you zap out and receive radio signals all across the spectrum. Add a PortaPack, and you can do that on the go — for diagnostic tests and white hat hacking only, of course. It’s a handy setup that you can use for all sorts of things, specifically radio things. But, Salvador Mendoza has come up with another interesting use for his PortaPack as a mag stripe reader and “replayer.”

    PortaPack: As FM Mag-stripe Decoder and “Replayer”
    https://blog.hackster.io/using-a-hackrf-one-portapack-as-a-mag-stripe-reader-and-replayer-36690c93772a

    Reply
  7. Tomi Engdahl says:

    Design a wireless IIoT gateway with open-source tools
    https://www.controleng.com/single-article/design-a-wireless-iiot-gateway-with-open-source-tools/ed524160bdc7942a3af1ce356126a7b4.html?OCVALIDATE=

    Wireless: Software-defined radio (SDR) hardware and open-source programming software provides an alternative to proprietary wireless communications systems, helping improve Industrial Internet of Things (IIoT) networks.

    Despite many discussions about how the Industrial Internet of Things (IIoT) will change factory automation, no unifying technology exists to connect various “things” together, which results in incompatibility among systems. Connections among disparate industrial wireless standards can be made with open-source software-defined radio (SDR) technologies.

    Compatibility issues can be best illustrated by looking at IIoT, an application subset where pervasive connectivity offers significant benefits. A leading communications equipment vendor estimated over 90% of industrial machinery is not currently connected to any network. Sensors can provide real-time information of production line efficiency and throughput, equipment loading, asset tracking, energy consumption, and monitoring device wear. Having this data will allow factories to increase efficiency, lower costs, predict maintenance requirements, and reduce machine downtime.

    The controlling computers can run machine-learning (ML) algorithms to detect patterns in data and tune program actions to get the most from the assets. The “Big Data” collected can be extracted for human analysis and comprehension. The vision of a fully interconnected and automated smart factory is sometimes called Industrie 4.0.

    The advantages of connected machinery are diminished unless data communications from the whole facility can be collected, analyzed, and shared between multiple data sources. This might be easier for a greenfield site where the installation of new machinery supporting open standards can be planned with this objective, Most industrial complexes, however, have an array of legacy equipment that needs retrofitting to become connected.

    Incompatible wireless standards

    The primary barrier to greater interconnectivity is the likelihood that multiple vendors supply machinery on most sites. Each vendor is likely to have a different approach to adopting IIoT, which includes wireless for maximum flexibility, but without interoperability among standards among wireless links and protocols. These include Wi-Fi, NB-IoT (also called Cat-NB1), LTE MTC Cat M1, Long Range (LoRa), Sigfox, Ingenu, WirelessHART, Weightless, 2G in the form of Extended coverage GSM IoT (EC-GSM-IoT), 3G, Bluetooth Low Energy (BLE), and ZigBee.

    Each technology has advantages and limits and the use case may dictate the selection. Low Power Wide Area Networking (LPWAN) schemes, such as LoRa, NB-IoT, and Sigfox, are better suited to longer range links with low data rates, while radio access via Wi-Fi and Bluetooth are very popular, but the range is limited. A new Wi-Fi variant called HaLow is being added to the mix. It uses IP packets and lower frequencies that give greater range and penetration.

    Radio access technologies

    Figure 2: Lime Microsystems’ LimeSDR software-defined radio (SDR) board, which is compact, programmable, open-source, full duplex, and can be configured by downloading code from an app store. Courtesy: High Tech Marketing, Lime MicrosystemsAn SDR can support a vast range of wireless technologies, is compact, programmable, open source, full duplex, and “app-enabled,” meaning it can be configured after downloading code from an app store. Such a radio requires a means to communicate and a controller, such as a dual transceiver field programmable radio frequency (FPRF) device and a field-programmable gate array (FPGA) chip. The board plugs into a suitable processor, which would typically be a PC unit, via a USB 3.0 connector or PCIe interface. A processor running Linux can be enabled with open source apps from the SoapySDR project, which can be used “as is” or modified to provide the exact requirements.

    Open-source Ubuntu-based apps are available for GSM and LoRa, with an active eco-system working on a raft of new applications.

    https://github.com/pothosware/SoapySDR/wiki

    Reply
  8. Tomi Engdahl says:

    GSM Sniffing: Voice Decryption 101 – Software Defined Radio Series #11
    https://www.youtube.com/watch?v=krJJKjYdwgc

    In this video I show how to capture GSM traffic over the air, and decrypt parts of our own voice call. As frequency hopping is enabled in our case, a “test call” is decrypted subsequently, to show the full process until I get my new SDR, and record a new video.

    Reply
  9. Tomi Engdahl says:

    Using A RTL-SDR To Learn About The GSM Network Around You, Hak5 1621
    https://www.youtube.com/watch?v=FqtJ-TvtLTQ

    This time Shannon and Darren explore the available GSM information using some Kali Linux, WireShark and a RTL-SDR. All that and more, this time on Hak5!

    Reply
  10. Tomi Engdahl says:

    The Beginner’s Guide To Software Defined Radio RTL-SDR
    https://www.youtube.com/watch?v=nB6XQSEFwVA

    Reply
  11. Tomi Engdahl says:

    Hacking Wireless Doorbells and Software Defined Radio tips – Hak5 1910
    https://www.youtube.com/watch?v=EZU2AZtfJbI

    In this episode of Hak5 we’re taking on more hacking sub 1 GHz gadget hacking and viewer questions about GQRX, the RTL-SDR and the new YARD Stick One.

    Reply
  12. Tomi Engdahl says:

    $20 Software Defined Radio Tunes In Everything!
    https://www.youtube.com/watch?v=3J7WoyKpMT4

    Software Defined Radio… this USB stick lets you listen to ALL the spectrum around ya! Shannon Morse walks though everything you need to know to get started!

    http://rtlsdr.org/softwarewindows

    Reply
  13. Tomi Engdahl says:

    Hacking the Wireless World with Software Defined Radio – 2.0
    https://www.youtube.com/watch?v=N0p3_ES2dBU

    “Ever wanted to communicate with a NASA space probe launched in 1978, or spoof a restaurant’s pager system? There are surprising similarities! How about use an airport’s Primary Surveillance RADAR to build your own bistatic RADAR system and track moving objects? What sorts of RF transactions take place in RFID systems, such as toll booths, building security and vehicular keyless entry? Then there’s ‘printing’ steganographic images onto the radio spectrum…

    Reply
  14. Tomi Engdahl says:

    Radio Hacking: Cars, Hardware, and more! – Samy Kamkar – AppSec California 2016
    https://www.youtube.com/watch?v=1RipwqJG50c

    In this talk I’ll introduce radio hacking, and take it a few levels into hacking real world devices like wirelessly controlled gates, garages, and cars. Many vehicles are now controlled from mobile devices over GSM and the web, while even more can be unlocked and ignitions started from wireless keyfobs over RF. All of these are subject to attack with low-cost tools (such as RTL-SDR, GNU Radio, HackRF, Arduino, and even a Mattel toy).

    We’ll investigate how these features work, and of course, how they can be exploited.

    Samy Kamkar
    Samy Kamkar is an independent security researcher, best known for creating The MySpace worm, one of the fastest spreading viruses of all time. His open source software and research highlights the insecurities and privacy implications in every day technologies, from the Evercookie which produces virtually immutable respawning cookies, SkyJack, the drone that wirelessly hijacks other drones, and KeySweeper, a wireless keyboard sniffer camouflaged as a USB wall charger. He continues to release new tools and hardware, for examples most recently the ProxyGambit, OpenSesame and ComboBreaker tools.

    Reply
  15. Tomi Engdahl says:

    Defcon 21 – All Your RFz Are Belong to Me – Hacking the Wireless World with Software Defined Radio
    https://www.youtube.com/watch?v=ZuNOD3XWp4A

    Reply
  16. Tomi Engdahl says:

    How to decode digital voice with RTL SDR
    https://www.youtube.com/watch?v=PjTRx8_KGiI

    Digital Speech Decoder (software package)
    http://wiki.radioreference.com/index.php/Digital_Speech_Decoder_%28software_package%29

    Digital Speech Decoder is an open source software package that decodes several digital speech formats. It uses the mbelib library (a separate open source package) to synthesize the decoded digital speech. It does not allow decoding of encrypted communications. It can save the compressed digital audio bits to “mbe” data files (.imb and .amb extensions) and play back those saved files. It’s discussed in this forum.

    The latest version (1.6) supports the following formats and modulation types:

    P25 Phase 1
    ProVoice EDACS Digital voice
    X2-TDMA – Motorola public safety TDMA system with P25 style signaling (mostly based on DMR)
    DMR/MOTOTRBO – Digital Mobile Radio standard
    NXDN – 9600 baud (12.5 kHz) NEXEDGE and 4800 baud (6.25 kHz) NEXEDGE/IDAS
    D-STAR – The Github version of dsd/mbelib can parse and play back D-STAR traffic.
    C4FM modulation
    GFSK modulation (including GMSK and other filtered 2/4 level FSK)
    QPSK modulation (sometimes marketed as “LSM”)

    Reply
  17. Tomi Engdahl says:

    The NSA’s Software Defined Radio application “RedHawk” is now open source
    https://swling.com/blog/2019/01/the-nsas-software-defined-radio-application-redhawk-is-now-open-source/?fbclid=IwAR0OmYbaIc9gJcNcktfiT3RbVPdO0ic9LgRwszJXPqLkXcazrAJvJ1yKr3M

    project called “RedHawk” which is described as:

    “A software-defined radio (SDR) framework designed to support the development, deployment, and management of real-time software radio applications.”

    Now, being curious I opened the github link:

    https://github.com/redhawksdr

    Reply
  18. Tomi Engdahl says:

    Spoofing Cell Networks with a USB to VGA Adapter
    https://hackaday.com/2018/04/23/spoofing-cell-networks-with-a-usb-to-vga-adapter/

    RTL-SDR brought cheap and ubiquitous Software Defined Radio (SDR) to the masses, opening up whole swaths of the RF spectrum which were simply unavailable to the average hacker previously. Because the RTL-SDR supported devices were designed as TV tuners, they had no capability to transmit. For the price they are still an absolutely fantastic deal, and deserve to be in any modern hacker’s toolkit, but sometimes you want to reach out and touch someone.

    Now you can. At OsmoDevCon [Steve Markgraf] released osmo-fl2k, a tool which allows transmit-only SDR through cheap USB 3.0 to VGA adapters based on the Fresco Logic FL2000 chip. Available through the usual overseas suppliers for as little has $5 USD, these devices can be used unmodified to transmit low-power FM, DAB, DVB-T, GSM, UMTS and GPS signals.

    https://osmocom.org/projects/osmo-fl2k/wiki/Osmo-fl2k

    Reply
  19. Tomi Engdahl says:

    A Classy SDR Chip, Decapped
    https://hackaday.com/2018/05/27/a-classy-sdr-chip-decapped/

    If you are a regular searcher for exotic parts among the virtual pages of semiconductor supplies catalogs, you will have probably noticed that for a given function it is most often the part bearing the Analog Devices logo that is the most interesting. It may have more functionality, perhaps it will be of a higher specification, and it will certainly have a much higher price. [Zeptobars] has decapped and analyzed an AD chip that holds all three of those honors, the AD9361 SDR transceiver.

    The AD9361 is an all-in-one SDR transceiver with an astonishing bandwidth, and as such was a particularly special device when it reached the market in 2013.

    The financial analysis puts Analog Devices’s gross profit at about $103 of the $275 retail purchase price of an AD9361. The biggest slice at $105 goes to the distributor, and surprisingly the R&D and manufacturing costs are not as large as you might expect.

    Analog Devices AD9361 – when microchips are more profitable than drugs
    https://zeptobars.com/en/read/AD9361-SDR-Analog-Devices-DAC-ADC-65nm

    Reply
  20. Tomi Engdahl says:

    Cheap Stuff To Hack: A Router With An SDR For $13
    https://hackaday.com/2018/05/30/cheap-stuff-to-hack-a-router-with-an-sdr-for-13/

    Now there’s a new device sitting on the shelves at Walmart just waiting for some Linux hackers to have a go. It’s the Tzumi MagicTV, a device that allows you to watch over-the-air television on your phone. What’s inside? It’s a WiFi router, an RTL-SDR, and a battery pack in one tiny package. The best part? It costs $13, and apparently Walmart is just blowing them out.

    Right now, there aren’t too many details on what’s going on inside the Tzumi MagicTV box, however, the discussion over on the RTLSDR subreddit has revealed enough to give us a good idea of what’s going on.

    https://www.reddit.com/r/RTLSDR/comments/8mlbps/tzumi_magictv_is_an_openwrt_board_rtlsdr/

    Reply
  21. Tomi Engdahl says:

    VCF East: SDR on the Altair 8800
    https://hackaday.com/2018/06/08/vcf-east-sdr-on-the-altair-8800/

    You’d be forgiven if you thought software defined radio (SDR) was a relatively recent discovery. After all, few outside of the hardcore amateur radio circles were even familiar with the concept until it was discovered that cheap USB TV tuners could be used as fairly decent receivers from a few hundred MHz all the way up into the GHz range. The advent of the RTL-SDR project in 2012 brought the cost of entry level SDR hardware from hundreds of dollars to tens of dollars effectively overnight. Today there’s more hackers cruising the airwaves via software trickery than there’s ever been before.

    All the way back in 1975, an article written by Steve Dompier was published in the People’s Computer Company Newsletter and republished in Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia in 1976 that described a very curious discovery. Nearly a decade before a team at Raytheon would coin the term “software radio”, the article showed that with just a few lines of code one could generate AM radio transmissions from their MITS Altair 8800.

    Reply
  22. Tomi Engdahl says:

    Radio Telescopes Horn In With GNU Radio
    https://hackaday.com/2019/01/20/radio-telescopes-horn-in-with-gnu-radio/

    Who doesn’t like to look up at the night sky? But if you are into radio, there’s a whole different way to look using radio telescopes. [John Makous] spoke at the GNU Radio Conference about how he’s worked to make a radio telescope that is practical for even younger students to build and operate.

    The only real high tech part of this build is the low noise amplifier (LNA) and the project is in reach of a typical teacher who might not be an expert on electronics. It uses things like paint thinner cans and lumber. [John] also built some blocks in GNU Radio that made it easy for other teachers to process the data from a telescope. As he put it, “This is the kind of nerdy stuff I like to do.” We can relate.

    The telescope is made to pick up the 21 cm band to detect neutral hydrogen from the Milky Way.

    https://www.gnuradio.org/grcon/grcon18/presentations/open_source_radio_telescopes/2-John_Makous-OSRT.pdf

    Reply
  23. Tomi Engdahl says:

    Lime SDR (and Pluto, Too) Sends TV
    https://hackaday.com/2019/01/19/lime-sdr-and-pluto-too-sends-tv/
    If you have experienced software defined radio (SDR) using the ubiquitous RTL SDR dongles, you are missing out on half of it. While those SDRs are inexpensive, they only receive. The next step is to transmit. [Corrosive] shows how he uses DATV Express along with a Lime SDR or a Pluto (the evaluation device from Analog Devices) to transmit video. He shows how to set it all up in the context of ham radio. An earlier video shows how to receive the signal using an SDR and some Windows software. The receiver will work with an RTL SDR or a HackRF board, too. You can see both videos, below.

    The DATV Express software has plenty of options and since SDR if frequency agile,

    https://www.youtube.com/watch?v=cyq_47qqhJg

    Reply
  24. Tomi Engdahl says:

    December 13, 2018
    Using a 25 Meter Radio Dish and an RTL-SDR as a SatNOGS Ground Station
    https://www.rtl-sdr.com/using-a-25-meter-radio-dish-and-an-rtl-sdr-as-a-satnogs-ground-station/

    SatNOGS is an open source project that aims to make it easy for volunteers to build and run RTL-SDR or other SDR based RF ground stations that automatically monitor satellites, and upload that data to the internet for public access. The antennas used in a typical home based SatNOGS station are small enough for a single person to handle, however recently the SatNOGS team have been working on setting up a monitoring station at the Dwingeloo Radio Observatory in the Netherlands.

    Dwingeloo has a large 25 meter satellite dish antenna, and they connect it to an RTL-SDR on a laptop running the SatNOGS software. In the video they show it tracking the PRISM amateur radio satellite

    https://satnogs.org/

    Reply
  25. Tomi Engdahl says:

    High-Speed Data Converters Make Direct-Sampling Receivers Practical
    https://www.electronicdesign.com/analog/high-speed-data-converters-make-direct-sampling-receivers-practical?NL=ED-003&Issue=ED-003_20190213_ED-003_707&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000002750211&utm_campaign=23331&utm_medium=email&elq2=5572b434f7cd40dea591b26cdc84f484

    Sponsored by Texas Instruments: Pushing beyond the superheterodyne, direct-sampling receivers can help meet the demands of today’s communications systems, but they need ultra-fast ADCs to make them work. Such converters have now arrived.

    Reply
  26. Tomi Engdahl says:

    Automate Your Home From the Clearance Rack
    https://hackaday.com/2019/01/19/automate-your-home-from-the-clearance-rack/

    [ModernHam] walks the viewer through the start to finish process of commanding these cheap remote plugs. Starting with finding which frequencies the remotes use thanks to the FCC database and ending with using cron to schedule the transmission of control signals from the Pi, his video really is a wealth of information. Even if you don’t have this particular model of remote plug, or don’t necessarily want to setup a home automation system, there’s probably some element of this video that you could still adapt to your own projects.

    Reply
  27. Tomi Engdahl says:

    Your USB Serial Adapter Just Became a SDR
    https://hackaday.com/2018/12/06/your-usb-serial-adapter-just-became-a-sdr/

    To say that the RTL-SDR project was revolutionary might be something of an understatement. Taking a cheap little USB gadget and using it as a Software Defined Radio (SDR) to explore the radio spectrum from the tens of megahertz all the way into gigahertz frequencies with the addition of nothing more than some open source tools may go down as one of the greatest hacks of the decade. But even in the era of RTL-SDR, what [Ted Yapo] has manged to pull off is still pretty incredible.

    With a Python script, a length of wire attached to the TX pin, and a mastery of the electron that we mere mortals can only hope to achieve, [Ted] has demonstrated using a common USB to serial adapter as an SDR transmitter. That’s right, using the cheap little UART adapter you’ve almost certainly got sitting in your parts bin right now and his software, you can transmit in the low megahertz frequencies and even up into VHF with some trickery. The project is still very much experimental, and though this may be the first time, we’re willing to bet this isn’t the last time you’ll be hearing about it.

    https://hackaday.io/project/162477-serial-port-sdr

    Reply
  28. Tomi Engdahl says:

    Jeremy Hong: Weaponizing the Radio Spectrum
    https://hackaday.com/2018/12/13/jeremy-hong-weaponizing-the-radio-spectrum/

    SDRs Take Wing

    Jeremy comes to this field more as an informed enthusiast than as an employee or contractor for one of the many alphabet agencies or defense contractors who jealously guard such secrets. A recent EE grad from Wright State University, where courses on electronic warfare (EW) are offered, Jeremy not only developed an interest in the field but has been able to observe some of the systems in action, thanks to nearby Wright-Patterson Air Force Base.

    Reply

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