software-defined radio

125 Articles

Radio Gets Ridiculous

December 21, 2018 by 16 Comments

There were plenty of great talks at this year’s Supercon, but we really liked the title of Dominic Spill’s talk: Ridiculous Radios. Let’s face it, it is one thing to make a radio or a computer or a drone the way you are supposed to. It is another thing altogether to make one out of things you shouldn’t be using. That’s [Dominic’s] approach. In a quick 30 minutes, he shows you two receivers and two transmitters. What makes them ridiculous? Consider one of the receivers. It is a software defined radio (SDR). How many bits should an SDR have? How about one bit? Ridiculous? Then you are getting the idea.

Dominic is pretty adept at taking a normal microcontroller and bending it to do strange RF things and the results are really entertaining. The breadboard SDR, for example, is a microcontroller with three components: an antenna, a diode, and a resistor. That’s it. If you missed the talk at Supercon, you can see the newly published video below, along with more highlights from Dominic’s talk.

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Hackaday Links: July 8, 2018

July 8, 2018 by 12 Comments

Software-defined radio has been around for years, but it’s only recently that it’s been accessible to those of us who don’t have tens of thousands of dollars worth of equipment in their lab. Here’s a new book from Analog Devices that gives you the lowdown on software-defined radio. It’s heavy on MATLAB and components from Analog, but it’s still a solid foundation for SDR.

Do you like cyberpunk? Do you like stories about rebellious people overthrowing the system? How about androids? Do you like androids? Here’s a Kickstarter that’s tying all of that together. Neptune Frost is (will be?) a movie about an e-waste village in Burundi that’s home to the ‘world’s most subversive hacking collective’, a coltan miner and an inter-sex runaway. It’s literally got everything.

Hey, this is cool, Hackaday has been cited in a journal article. The title of the article is An open-source approach to automation in organic synthesis: The flow chemical formation of benzamides using an inline liquid-liquid extraction system and a homemade 3-axis autosampling/product-collection device,  and can be found in Tetrahedron Volume 74, Issue 25, 21 June 2018, Pages 3152-3157.

Asteroid day was a few days ago, and there’s a Kickstarter to go with it. The Planetary Society, headed up by Bill Nye (a science guy) is raising awareness about the threat of asteroid impacts. There’s hilarious swag that says ‘Kick Asteroid’, even though actually kicking an asteroid might be a bad idea; a gravity tractor would be the best method of nudging the orbit of an asteroid given enough time.

Last year, a company in the US trademarked the word ‘RetroPie’ and used that trademark to sell Raspberry Pis loaded up with (you guessed it) RetroPie software. This company also used the trademark to force anyone else doing the same to stop. Obviously, this didn’t sit well with the developers of RetroPie. After some generous legal help, the RetroPie trademark issue has been resolved. That’s a tip of the hat to Eckland & Blando who offered some pro bono legal work.

Free E-Book: Software Defined Radio For Engineers

June 29, 2018 by 10 Comments

We really like when a vendor finds a great book on a topic — probably one they care about — and makes it available for free. Analog Devices does this regularly and one you should probably have a look at is Software Defined Radio for Engineers. The book goes for $100 or so on Amazon, and while a digital copy has pluses and minuses, it is hard to beat the $0 price.

The book by [Travis F. Collins], [Robin Getz], [Di Pu], and [Alexander M. Wyglinski] covers a range of topics in 11 chapters. There’s also a website with more information including video lectures and projects forthcoming that appear to use the Pluto SDR. We have a Pluto and have been meaning to write more about it including the hack to make it think it has a better RF chip inside. The hack may not result in meeting all the device specs, but it does work to increase the frequency range and bandwidth. However, the book isn’t tied to a specific piece of hardware.

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Homebrew SDR Ham Radio In 9 Parts

June 6, 2018 by 31 Comments

It used to be homebrew ham gear meant something simple. A couple of active devices that could send CW. Maybe a receiver with a VFO. But only the most advanced builders could tackle a wide range SSB transceiver. Today, that goal is still not trivial, but it is way easier due to specialty ICs, ready access to high-speed digital signal processing, and advances in software-defined radio techniques. [Charlie Morris] decided to build an SSB rig that incorporated these technologies and he shared the whole process from design to operation in a series of nine videos. You can see the first one below.

The NE612 is a child of the popular NE602 chip, which contains a Gilbert-cell mixer, and an oscillator that makes building a receiver much easier than it has been in the past. The chips are set up as direct conversion receivers and feed a Teensy which does the digital signal processing on the recovered audio.

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Dual SDR Receives Two Bands At Once

May 21, 2018 by 15 Comments

There was a time when experimenting with software defined radio (SDR) was exotic. But thanks to cheap USB-based hardware, this technology is now accessible to anyone. While it is fun to play with the little $20 USB sticks, you’ll eventually want to move up to something better and there are a lot of great options. One of these is SDRPlay, and they recently released a new piece of hardware — RSPduo — that incorporates dual tuners.

We’ve talked about using the SDRPlay before as an upgrade from the cheap dongles. The new device can tune either a single 10 MHz band over the range of 1 kHz to 2 GHz, or you can select two 2 MHz bands. This opens up a lot of applications where you need to pick up signals in different areas of the spectrum (e.g., monitoring both sides of a cross-band repeater).

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Icoboard Software Defined Radio Platform

March 20, 2018 by 8 Comments

The Icoboard is a plug-in for the Raspberry Pi with a Lattice iCE FPGA onboard. Combined with a cheap A/D converter, [OpenTechLab] build a software-defined radio using all open source tools. He found some inexpensive converters that cost about $25 and were fast enough (32 MHz) for the purpose at hand. The boards also had a digital to analog converter and he was able to find the data sheets. You can see a video with the whole project covered, below.

The video, by the way, is pretty extensive (about an hour’s worth) and covers the creation of a PC board to connect from the Icoboard to the converters. There’s also a 3D printed frame, and that’s explained in detail as well.

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Image Source: Brannon Dorsey

Art Eavesdrops On Life And Pagers

December 24, 2017 by 32 Comments

Before cell phones, pagers were the way to communicate on the go. At first, they were almost a status symbol. Eventually, they became the mark of someone who couldn’t or wouldn’t carry a cell phone. However, apparently, there are still some users that clutch their pagers with a death grip, including medical professionals. In an art project called HolyPager, [Brannon Dorsey] intercepted all the pager messages in a city and printed them on a few old-style roll printers. The results were a little surprising. You can check out the video below.

Almost all the pages were medical and many of them had sensitive information. From a technical standpoint, [Brannon’s] page doesn’t shed much light, but an article about the project says that it and other art projects that show the hidden world or radio waves are using our old friend the RTL-SDR dongle.

Pagers use a protocol — POCSAG — that predates our modern (and well-founded) obsession with privacy and security. That isn’t surprising although the idea that private medical data is flying through the air like this is. Decoding POCSAG isn’t hard. GNU Radio, for example, can easily handle the task.

We’ve looked at pager hacking in the past. You can even run your own pager network, but don’t blame us if you get fined.

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