Digitize An Analogue Oscilloscope

May 31, 2020 by Jenny List 13 Comments

Many of us will possess digital oscilloscopes which offer at an affordable price an array of features once unimaginable on the analogue CRT ‘scopes of yesteryear. But those old analogue beasts were fine pieces of equipment when they were made and remain so today. So how can they find a place in the digital age?

Perhaps [Joseph Eoff] has the answer, because he’s fitted his trusty Telequipment D43 with a camera in a 3D-printed attachment, paired with a piece of cross-platform Python/Qt custom software using OpenCV to identify, digitize, and quantify the traces. The software allows viewing the either the digitized trace or the real trace, and derives measurements of voltage and frequency from them. One limitation is that despite the ‘scope being a dual-trace model, the software only has a single set of cursors to measure one trace at a time. All the code can be had from the GitHub repository, should you wish to experiment with it or extend it.

It’s worth thinking for a minute at what price point a remotely decent digital ‘scope starts, then considering the ease with which surprisingly good older analogue instruments can be found on the second-hand market for not a lot. An approach such as this one makes them an even more attractive proposition.

If you’re looking further into enhancements for an analogue ‘scope, how about a logic analyser?

A Tasty Output Device

May 30, 2020 by Al Williams 11 Comments

We have headphones for your ears, and monitors for your eyes. Some computers even have tactile feedback. Now researchers have an output device for taste. The decidedly odd device uses five gels, one for each of the tastes humans can sense. If we understand the paper, the trick is that ionizing the gels inhibits the taste of that gel. By controlling the ionization level of each gel, you can synthesize any taste, just like you can make colors with three LEDs.

The five gels are made from agar and glycine (sweet), magnesium chloride (bitter), citric acid (acidic), salt (salty), and glutamic sodium (umami). If you didn’t learn about umami in school, that’s a savory taste likened to the taste of a broth or meat and often associated with monosodium glutamate.

The shape of the device is made like a sushi roll so that while the gels contact the tongue, a copper foil cathode can connect also. Using this will make you look even stranger than someone wearing Google Glass, but that’s the price of being on the cutting edge of technology, we suppose. There doesn’t seem to be any reason you couldn’t duplicate something like this, although we wonder about the hygiene of passing it around at parties. Maybe your next home movie could show a meal and let the viewer taste it too.

If you are wondering about smell, that’s another set of researchers. You would think this is the first taste output device we have seen, but no… surprisingly, it isn’t.

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Swap Your Microwave For A High Voltage Stereo

May 30, 2020 by Bryan Cockfield 31 Comments

When building a new project, common wisdom suggests to avoid “reinventing the wheel”, or doing something simple from scratch that’s easily available already. However, if you can build a high-voltage wheel, so to speak, it might be fun just to see what happens. [Dan] decided to reinvent not the wheel, but the speaker, and instead of any conventional build he decided to make one with parts from a microwave and over 6,000 volts.

The circuit he constructed works essentially like a Tesla coil with a modulated audio signal as an input. The build uses the high voltage transformer from the microwave too, which steps the 240 V input up to around 6 kV. To modulate that kind of voltage, [Dan] sends the audio signal through a GU81M vacuum tube with the support of a fleet of high voltage capacitors. The antenna connected to the magnetron does tend to catch on fire somewhere in the middle of each song, so it’s not the safest device around even if the high voltage can be handled properly, but it does work better than expected as a speaker.

If you want a high-voltage speaker that (probably) won’t burn your house down, though, it might be best to stick to a typical Tesla coil. No promises though, since working with high voltages typically doesn’t come with safety guarantees.

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This Old Console Stereo Hides A Liquor Cabinet

May 30, 2020 by Jenny List 10 Comments

There was a time when consumer electronics were statement items, designed to resemble quality furniture that would be shown off as a centerpiece of the home. Televisions in ornate wooden cabinets, or stereos looking for all the world like sideboards. [Zethus] had just such a huge record player and radio combo in a sideboard, and having little use for the cream of 1950s home entertainment technology, he rebuilt it as a concealed liquor cabinet with electronic controls and a much more modern stereo that forms part of a Logitech Media Server multi-room system.

After removing the tube-based radio chassis and Garrard jockey-wheel turntable it was time to gut their supporting woodwork and install the platform derived from a standing desk. With suitably impressive lighting and a pair of VFD displays for the music choice, there is the inevitable Raspberry Pi running the show. Control is achieved by a set of hidden capacitive buttons, and there’s a Web interface to allow both music and magical appearance of alcohol from the comfort of a smartphone. The whole can be seen in the video below the break.

Whenever a piece of vintage electronics is gutted in this way there will always be people who find it disquieting, but the truth is that these all-in-one stereos were made in huge quantities during the mid-century period and do not have a significant value. This one may have lost its original electronics, but it lives on safe from the dump that has claimed so many of its brethren. Happily this isn’t the first one we’ve seen saved with a Pi.

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DMCA Vs Hacker

May 30, 2020 by Elliot Williams 46 Comments

This week featured a large kerfuffle over a hack that you probably read about here on Hackaday: [Neutrino] wedged an OLED screen and an ESP32 into a Casio calculator. REACT, an anti-counterfeiting organization, filed DMCA copyright takedowns on Casio’s behalf everywhere, including GitHub and YouTube, and every trace of [Neutrino]’s project was scrubbed from the Internet.

The DMCA is an interesting piece of legislation. It’s been used to prevent people from working on their tractors, from refilling printer ink cartridges, and to silence dissenting opinions, but it’s also what allows us to have the Internet that we know and love, in a sense.

In particular, the “safe harbor” provision absolves online platforms like YouTube and GitHub from liability for content they host, so long as they remove it when someone makes a copyright claim on it. So if a content owner, say Casio, issues a takedown notice for [Neutrino]’s GitHub and YouTube content, they have to comply. If he believes the request to be made in error, [Neutrino] can then file a counter-notice. After ten to fourteen days, presuming no formal legal action has been taken, the content must be reinstated. (See Section 512(g).)

Both the takedown notice and counter-notice are binding legal documents, sworn under oath of perjury. Notices and counter-notices can be used or abused, and copyright law is famously full of grey zones. The nice thing about GitHub is that they publish all DMCA notices and counter-notices they receive, so here it is for you to judge yourself.

Because of the perjury ramifications, we can’t say that the folks at REACT who filed the takedown knowingly submitted a bogus request in bad faith — that would be accusing them of breaking federal law — but we can certainly say that it looks like they’re far off base here. They’re certainly not coders.

The good news is that the code is back up on GitHub, but oddly enough the video describing the hack is still missing on YouTube.

But here’s how this looks for Casio and REACT: they saw something that was unflattering to a product of theirs — that it could be used for cheating in school — and they sent in the legal attack squad. If that’s the case, that’s rotten.

Build Your Own Dial-Up ISP – Now With Modem Pool!

May 30, 2020 by Lewin Day 54 Comments

When it was the only viable option, the screech and squeal of dial-up internet was an unwelcome headache to many. But now that its time has passed, it’s gained a certain nostalgia that endears it to the technophiles of today. [Doge Microsystems] is just one such person, who has gone all out to develop their very own dial-up ISP for multiple clients.

The retro network is based on an earlier single-device experiment, with a Raspberry Pi 3B acting as the dial-up server. It’s hooked up to four modems, three of which are connected over USB-serial adapters implementing hardware flow control.

Obviously, four analog phone lines are hard to come by in this day and age, so [Doge] uses Asterisk along with a series of Linksys SIP devices to create their own PBX network. Each modem gets a phone line, with four left over for clients to dial in.

To connect, users can either call a certain modem directly, or dial a special number which rings the whole pool. Thanks to mgetty, each modem is set up to answer on a different number of rings to allow the load to be shared. Once connected, a PPP daemon handles connecting the user to the Internet at large.

While it’s unlikely we’ll all be ringing [Doge]’s house to get our next YouTube fix, owning your own dial-up ISP is certainly an admirable feat. We’d love to see it deployed in the field sometime, perhaps at a hacker conference or Burning Man-type event. Of course, if you’ve got your own old-school network pumping data, be sure to let us know! Video after the break.

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Spacing Out: All The Orbital News You’re Missing

May 30, 2020 by Jenny List 19 Comments

We keep finding more great space stories than we can cover, so here’s a speed-run through the broader picture of the moment as it applies to space flight.

The big news this week was the first launch of a manned SpaceX Crew Dragon capsule to the ISS. I was excited because the pass en route to the space station was scheduled to be visible from the UK at dusk, and on Wednesday evening I perched atop a nearby hill staring intently at the horizon. Except it had been cancelled due to bad weather. The next launch window is planned for today and you can watch it live.

Meanwhile, fashion is the other piece of this manned-launch’s appeal. Their sharply-designed spacesuits have attracted a lot of attention, moving on from the bulky functional Michelin Man aesthetic of previous NASA and Roscosmos garments for a positively futuristic look that wouldn’t be out of place in Star Trek. Never mind that the two astronauts are more seasoned space dog than catwalk model, they still look pretty cool to us. Against the backdrop of a political upheaval at the top of NASA, this first crewed orbital mission from American soil since the retirement of the Shuttle has assumed an importance much greater than might be expected from a run-of-the-mill spaceflight.

While we’re on the subject of the ISS, it’s worth noting that we’re approaching twenty years since the first crew took up residence there, and it has been continuously crewed ever since as an off-planet outpost. This is an astounding achievement for all the engineers, scientists, and crews involved, and though space launches perhaps don’t have the magic they had five decades ago it’s still an awe-inspiring sight to see a man-made object big enough to discern its shape pass over in the night sky. We understand that current plans are to retain the station until at least 2030, so it’s a sight that should remain with us for a while longer.

Closer to Earth are a couple of tests for relative newcomers to the skies. When Richard Branson’s Virgin group isn’t trying to boot millionaires off the planet through its Virgin Galactic operation, it’s aiming to cheaply fling small satellites into orbit from a rocket-toting airborne Boeing 747 with its Virgin Orbit subsidiary. Their first test launch sadly didn’t make it to space, once the rocket had flawlessly launched from the airliner it suffered a fault and the mission had to be aborted. Getting into space is hard.

The second test was never intended to make it into space, but is no less noteworthy. The British company Skyrora have performed a successful ground test of their Skylark L rocket, aiming for a first launch next year and for offering low-earth orbit services by 2023. This is significant because it will be the first British launch since the ill-fated Black Arrow launch in 1971, and with their Scottish launch site the first ever from British soil. If you’ve seen Skyrora mentioned here before, it is because they were behind the retrieval of the Black Arrow wreckage from the Aussie outback that we mentioned when we wrote about that programme.

Looking forward to the coming week, especially today’s rescheduled SpaceX launch. This time however, I’ll check the weather conditions before climbing any hills.