Hackaday Links: December 29, 2019

The retrocomputing crowd will go to great lengths to recreate the computers of yesteryear, and no matter which species of computer is being restored, getting it just right is a badge of honor in the community. The case and keyboard obviously playing a big part in that look, so when a crowdfunding campaign to create new keycaps for the C64 was announced, Commodore fans jumped to fund it. Sadly, more than four years later, the promised keycaps haven’t been delivered. One disappointed backer, Jim Drew, decided he was sick of waiting, so he delved into the world of keycaps injection molding and started his own competing campaign. Jim details his adventures in his Kickstarter Indiegogo campaign, which makes for good reading even if you’re not into Commodore refurbishment. Here’s hoping Jim has better luck than the competition did.

Looking for anonymity in our increasingly surveilled world? You’re not alone, and in fact, we predict facial recognition spoofing products and methods will be a growth industry in the new decade. Aside from the obvious – and often illegal – approach of wearing a mask that blocks most of the features machine learning algorithms use to quantify your face, one now has another option, in the form of a colorful pattern that makes you invisible to the YOLOv2 algorithm. The pattern, which looks like a soft-focus crowd scene rendered in Mardi Gras colors, won’t make the algorithm think you’re someone else, but it will prevent you from being classified as a person. It won’t work with any other AI algorithm, but it’s still an interesting phenomenon.

We saw a great hack come this week about using an RTL-SDR to track down a water leak. Clayton’s water bill suddenly skyrocketed, and he wanted to track down the source. Luckily, his water meter uses the encoder receive-transmit (ERT) protocol on the 900 MHz ISM band to report his usage, so he threw an SDR dongle and rtlamr at the problem. After logging his data, massaging it a bit with some Python code, and graphing water consumption over time, he found that water was being used even when nobody was home. That helped him find the culprit – leaky flap valves in the toilets resulting in a slow drip that ran up the bill. There were probably other ways to attack the problem, but we like this approach just fine.

Are your flex PCBs making you cry? Friend of Hackaday Drew Fustini sent us a tip on teardrop pads to reduce the mechanical stress on traces when the board flexes. The trouble is that KiCad can’t natively create teardrop pads. Thankfully an action plugin makes teardrops a snap. Drew goes into a bit of detail on how the plugin works and shows the results of some test PCBs he made with them. It’s a nice trick to keep in mind for your flexible design work.

Russia’s Newest Weather Satellite May Have Been Killed By Space Junk

For humans and satellites alike, making a living in space is hard. First, there’s the problem of surviving the brief but energetic and failure-prone ride there, after which you get to alternately roast and freeze as you zip around the planet at 20 times the speed of sound. The latter fact is made all the more dangerous by the swarm of space debris, both natural and man-made, that whizzes away up there along with you, waiting to cause an accident.

One such accident has apparently led to the early demise of a Russian weather satellite. Just a few months after launch, Meteor-M 2-2 suffered a sudden orbital anomaly (link to Russian story; English translation). Analysis of the data makes it pretty clear what happened: the satellite was struck by something, and despite some ground-controller heroics which appear to have stabilized the spacecraft, the odds are that Meteor-M 2-2 will eventually succumb to its wounds.

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Hackaday Links: December 1, 2019

We can recall a book from our youth that cataloged some of the most interesting airplanes in the world. One particularly interesting beast was dubbed “The Super Guppy”, a hilariously distended cargo plane purpose-built for ferrying Saturn rocket sections around the US in the 1960s. We though the Guppies were long gone, victims like so many other fascinating machines of the demise of the Apollo program. It turns out we were only 4/5 right about that, since one of the original five Super Guppies is still in service, and was spotted hauling an Orion capsule from Florida to Ohio for vacuum testing. The almost 60-year-old plane, a highly modified C-97 Stratofreighter, still has a big enough fan-base to attract 1500 people to brave the Ohio cold and watch it land.

The news this week was filled with reports from Texas of a massive chemical plant explosion that forced the evacuation of 50,000 people from their homes the day before Thanksgiving. The explosion and ensuing fire at the TPC Group petrochemical plant were spectacular; thankfully, there were no deaths and only two injuries reported from the incident. The tie-in to the hacker community lies in what this plant made: butadiene, or synthetic rubber. The plant produced about 16% of the North American market’s supply of butadiene, which we know from previous coverage is one of the polymers in acrylonitrile butadiene styrene, or ABS. It remains to be seen if this will put a crimp in ABS printer filament supplies, or any of the hundreds of products that butadiene is in, including automotive tires and hoses.

Remember when “Cyber Monday” became a thing? We sure do; in the USA, it was supposed to be the first workday back from the Thanksgiving break which would afford those lacking a fast Internet connection at home the opportunity to do online shopping on company time. The idea seems so year 2000 now, but the name stuck, and all kinds of sales and bargains are now competing for your virtual attention and cyber dollars. That includes Tindie, of course, where the Cyber Monday Sale is running through December 6. There’s tons to chose from, including products that got started as Hackaday.io projects and certified open-source hardware products. Be sure to check out the Tindie Twitter feed and blog for extra discount codes, too.

Speaking of gift-giving, we got an interesting tip about a product we never knew we needed. Called “WorkBench”, it’s a modular development system that takes care of an oft-neglected side of prototyping: the physical and mechanical layout. Too often we just start with a breadboard on the bench, and while that’ll do for lots of smaller projects, as the build keeps growing and the breadboards keep coming, things can get out of hand. WorkBench aims to tidy things up by providing a basal platen onto which breadboards, microcontrollers, perfboards, or just about anything else can be snapped. Handles make the whole thing portable, and a clear acrylic cover protects your hard work.

We love to hear stories about citizen science, especially when the amateurs scoop the professionals. Astronomy seems to be a hotbed for this brand of discovery, usually as a lone astronomer peering into the night sky to see a comet or asteroid nobody has seen before. Catching a glitching pulsar in the act is an entirely different level of discovery, though. Back in February, Steve Olney detected a 2.5 parts-per-million increase in the 89-millisecond period of emissions for the Vela pulsar using his RTL-SDR-based observatory. Steve has some fascinating information about pulsars and his observatory on his website. Color us impressed that he was able to pull off this observation without the benefit of millions of dollars in equipment and a giant parabolic dish antenna.

Roofing Radio Telescope Sees The Galaxy

[David Schneider] asked himself, “How big a radio antenna would you need to observe anything interesting?” The answer turns out to be a $150 build of a half meter antenna. He uses it to detect the motions of the spiral arms of the Milky Way. The first attempt was a satellite TV dish and a cantenna feed, which didn’t work as the can wasn’t big enough to pick up signals at the 21cm wavelength of hydrogen emissions. Interstellar gas clouds are known to emit radio energy at this frequency.

Looking online, [David] tried aluminized foam board insulation, but was worried that the material didn’t seem to actually be conductive. A quick thrown-together Faraday cage with a cell phone didn’t seem to block any calls. Abandoning that approach, he settled on aluminum flashing used for roofing.

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A Miniature Radio Telescope In Every Backyard

You probably wouldn’t expect to see somebody making astronomical observations during a cloudy day in the center of a dense urban area, but that’s exactly what was happening at the recent 2019 Philadelphia Mini Maker Faire. Professor James Aguirre of the University of Pennsylvania was there demonstrating the particularly compact Mini Radio Telescope (MRT) project built around an old DirecTV satellite dish and a smattering of low-cost components, giving visitors a view of the sky in a way most had never seen before.

Thanks to the project’s extensive online documentation, anyone with a spare satellite dish and a couple hundred dollars in support hardware can build their very own personal radio telescope that’s capable of observing objects in the sky no matter what the time of day or weather conditions are. Even if you’re not interested in peering into deep space from the comfort of your own home, the MRT offers a framework for building an automatic pan-and-tilt directional antenna platform that could be used for picking up signals from orbiting satellites.

With the slow collapse of satellite television in the United States these dishes are often free for the taking, and a fairly common sight on the sidewalk come garbage day. Perhaps there’s even one (or three) sitting on your own roof as you read this, waiting for a new lease on life in the Netflix Era.

Whether it’s to satisfy your own curiosity or because you want to follow in Professor Aguirre’s footsteps and use it as a tool for STEM outreach, projects like MRT make it easier than ever to build a functional DIY radio telescope.

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Software Defined Radio Hack Chat

Join us on Wednesday, September 18 at noon Pacific for the Software Defined Radio Hack Chat with Corrosive!

If you’ve been into hobby electronics for even a short time, chances are you’ve got at least one software-defined radio lying around. From the cheap dongles originally intended to watch digital TV on a laptop to the purpose-built transmit-capable radio playgrounds like HackRF, SDR has opened up tons of RF experimentation. Before SDR, every change of band or mode would need new hardware; today, spinning up a new project is as simple as dragging and dropping a few blocks around on a screen, and SDRs that can monitor huge swaths of radio spectrum for the tiniest signal have been a boon to reverse engineers everywhere.

Corrosive is the handle of Harold Giddings, amateur callsign KR0SIV, and he’s gotten into SDR in a big way. Between his blog, his YouTube channel, and his podcast, all flying under the Signals Everywhere banner, he’s got the SDR community covered. Whether it’s satellite communications, aircraft tracking, amateur radio, or even listening in on railway operations, Harold has tried it all, and has a wealth of SDR wisdom to share. Join us as we discuss the state of the SDR ecosystem, which SDR to buy for your application, and even how to transmit with an SDR (hint: you’ll probably want a ham license.)

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 18 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Ham Radio Gets Embedded RTL-SDR

We usually think of the RTL-SDR as a low-cost alternative to a “real” radio, but this incredible project spearheaded by [Rodrigo Freire] shows that the two classes of devices don’t have to be mutually exclusive. After nearly 6 months of work, he’s developed and documented a method to integrate a RTL-SDR Blog V3 receiver directly into the Yaesu FT-991 transceiver.

The professional results of the hack are made possible by the fact that the FT-991 already had USB capability to begin with. More specifically, it had an internal USB hub that allowed multiple internal devices to appear to the computer as a sort of composite device.

Unfortunately, the internal USB hub only supported two devices, so the first order of business for [Rodrigo] was swapping out the original USB2512BI hub IC with a USB2514BI that offered four ports. With the swap complete, he was able to hang the RTL-SDR device right on the new chip’s pins.

Of course, that was only half of the battle. He had a nicely integrated RTL-SDR from an external standpoint, but to actually be useful, the SDR would need to tap into the radio’s signal. To do this, [Rodrigo] designed a custom PCB that pulls the IF signal from the radio, feed it into an amplifier, and ultimately pass it to the SDR. The board uses onboard switches, controlled by the GPIO ports on the RTL-SDR Blog V3, for enabling the tap and preamplifier.

In the video after the break, you can see [Rodrigo] demonstrate his modified FT-991. This actually isn’t the first time somebody has tapped into their Yaesu with a software defined radio, though this is surely the cleanest install we’ve ever seen.

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