The Weather Station At The Top Of The World

August 10, 2020 by 14 Comments

The crown jewels of the Earth’s mountain ranges, the Himalayas, are unsurpassed in their beauty, their height, and their deadly attraction to adventurers, both professional and amateur. The gem of the Himalayas is, of course, Mount Everest, known as Sagarmatha to the Nepalis and Chomolungma to the Tibetans. At 8,848 meters (29,029 ft) — or more; it’s a geologically young mountain that’s still being thrust upward by tectonic activity — it’s a place so forbidding that as far as we know the summit was never visited until 1953, despite at least 30 years of previous attempts, many of which resulted in death.

The conquest of Everest remains a bucket list challenge for many adventurers, and despite advances in technology that have made the peak accessible to more people — or perhaps because of that — more than 300 corpses litter the mountain, testament to what can happen when you take the power of Mother Nature for granted.

To get better data on the goings-on at the Roof of the World, an expedition recently sought to install five weather stations across various points on the route up Mount Everest, including one at its very peak. The plan was challenging, both from a mountaineering perspective and in terms of the engineering required to build something that would be able to withstand some of the worst conditions on the planet, and to send valuable data back reliably. It didn’t all go exactly to plan, but it’s still a great story about the intersection of science and engineering.

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The Zero Terminal 3: A Pop-Out Keyboard Linux Computer In Your Pocket

August 10, 2020 by 35 Comments

The mobile phone revolution has delivered us attractively packaged and convenient computing in our pockets, but without the easy hackability we like in our community. Meanwhile the advent of single board computers has given us affordable super-powerful hardware that can run a very capable GNU/Linux operating system and fulfill all our hackable computing needs. Combine the two though? Plenty have tried, few have succeeded in making something as slick as the former with the open power of the latter. Fine if you like your portable devices to have a cyberdeck vibe, but maybe not something you’d take into the boardrooom. Never fear though, for [N-O-D-E] have the solution, in version 3 of the Zero Terminal. It’s the ultimate in Raspberry Pi based handheld computing, and it resembles a slightly chunky mobile phone.

At its heart is a Waveshare OLED 5.5″ touch screen, on the back owhich is mounted a PCB that carries a USB hub and power circuitry. A Pi Zero is mounted directly to this, and a cleverly designed HDMI adapter board interfaces it to the display. The power board is a generic one, the one designed for the PCB proved difficult to hand solder. There’s a very smartly designed case to give it that mobile phone feel, and on the back are a set of sockets with all the relevant Pi connections. This opens the possibility of some exciting add-ons, the first of which is a sliding keyboard similar to those on early Android phones. The ‘board is based on a [Bobricius] design, though sadly isn’t quite working yet.

As you can see in the video below the break, this is about as slick a mobile Pi as it’s possible to get. [N-O-D-E], we want one. Just take our money!

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Unique Instrument Plucks Out Notes On A Ruler

August 10, 2020 by 18 Comments

How does one describe the notes that come from a ruler that is anchored on one end and then plucked? The best word we can come up with is “wubulation”. So would that make this ruler-plucking synthesizer a “wubulator”? Or perhaps a “wubatron”?

Whatever we decide to call it, [Dmitry Morozov] dubbed it the RBS-20, or “ruler bass synth, 20-cm”, for the 20-cm stainless steel ruler that forms the heart of the instrument. The ruler is attached to a linear slide which varies the length of the sprung section. A pair of servos can pluck the free section of the ruler in two different places, providing notes in different registers, while another pair of servos control metal fingers that can damp the vibration, change the sustain, and alter the notes. There’s no resonator; the sounds are instead picked up by a piezo mic. Twelve keys on the base of the instrument can be programmed for various lengths, and an OLED display gives the musician feedback. The video below shows the instrument wubulating, and brings us back to those desktop jam sessions in our grade school days — at least until the rulers were confiscated.

We’ve covered a ton of similarly unique musical instruments before, like this hybrid synthesizer-violin, a symphony of soda bottles, and inexplicably, a leg guitar.

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45 Minute Podcast Served Up On A Floppy Disk

August 9, 2020 by 37 Comments

Near the turn of the millenium, portable media players like the iPod led to the development of the podcast. The format generally consists of content similar to talk-based radio, and is typically served up in modern codecs like AAC, M4A and MP3. However, [Sean Haas] decided these were all too chunky, and wanted to see if it was possible to deliver similar content on a floppy disk. The results are predictable, but impressive.

[Sean]’s aim was to try and fit roughly 45 minutes of audio on to a 1.44 MB floppy disk. To pull this off, he looked far and wide for a codec fitting for the task. The choice landed on was Adaptive Multi-Rate, or AMR. Typically used to encode audio for GSM phone calls, it can also be used to create compressed audio files.

Initial attempts weren’t quite good enough to do the job, so [Sean] introduced a pre-processing step with FFMPEG, to speed the audio up 1.2 times. It was then passed through SoX and encoded in AMR at approximately 5 kbit/s. This allowed a 45-minute long MP3 file of 72MB to be compressed down into just 1.2 MB, and thus able to fit onto a floppy disk. Audio quality is predictably poor, as you can hear in the embedded clip below, but definitely intelligible. You’d probably want to skip any musical passages if you were doing this seriously.

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Talking Head Teaches Laplace Transform

August 9, 2020 by 25 Comments

Most people who deal with electronics have heard of the Fourier transform. That mathematical process makes it possible for computers to analyze sound, video, and it also offers critical math insights for tasks ranging from pattern matching to frequency synthesis. The Laplace transform is less familiar, even though it is a generalization of the Fourier transform. [Steve Bruntun] has a good explanation of the math behind the Laplace transform in a recent video that you can see below.

There are many applications for the Laplace transform, including transforming types of differential equations. This comes up often in electronics where you have time-varying components like inductors and capacitors. Instead of having to solve a differential equation, you can perform a Laplace, solve using common algebra, and then do a reverse transform to get the right answer. This is similar to how logarithms can take a harder problem — multiplication — and change it into a simpler addition problem, but on a much larger scale.

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Hackaday Links: August 9, 2020

August 9, 2020 by 15 Comments

We regret to admit this, but we completely missed the fact that Windows 10 turned five years old back in March. Granted, things were a little weird back then — at least it seemed weird at the time; from the current perspective, things were downright normal then. Regardless, our belated congratulations to Microsoft, who, like anyone looking after a five-year-old, spends most of their time trying to keep their charge from accidentally killing itself. Microsoft has done such a good job at keeping Windows 10 alive that it has been installed on “one billion monthly active devices”. Of course, back in April of 2015 they predicted that the gigainstall mark would be reached in 2018. But what’s a couple of years between friends?

Of all the things that proved to be in short supply during the pandemic lockdowns, what surprised us most was not the toilet paper crunch. No, what really surprised us was the ongoing webcam supply pinch. Sure, it makes sense, with everyone suddenly working from home and in need of a decent camera for video conferencing. But we had no idea that the market was so dominated by one manufacturer — Logitech — that their cameras could suddenly become unobtainium. Whatever it is that’s driving the shortage, we’d take Logitech’s statement that “demand will be met in the next 4-6 weeks” with a huge grain of salt. After all, back-to-school shopping is likely to look vastly different this year than in previous years.

Speaking of education, check out the CrowPi2 STEM laptop. On the one hand, it looks like just another Raspberry Pi-based laptop, albeit one with a better level of fit and finish than most homebrew Pi-tops. With a Raspberry Pi 4b on board, it can do all the usual stuff — email, browse the web, watch videos. The secret sauce is under the removable wireless keyboard, though: a pretty comprehensive electronics learning lab. It reminds us of the Radio Shack “150-in-One” kits that so many of us cut our teeth on, but on steroids. Having a complete suite of modules and a breadboarding area built right into the laptop needed to program it is brilliant, and we look forward to seeing how the Kickstarter for this does.

Exciting news from Hackaday Superfriend Chris Gammell — he has launched a new podcast to go along with his Contextual Electronics training courses. Unsurprisingly dubbed the Contextual Electronics Podcast, he already has three episodes in the can. They’re available as both video and straight audio, and from the few minutes we’ve had to spend on them so far, Chris has done a great job in terms of production values and guests with Sophy Wong, Stephen Hawes, and Erik Larson leading off the series. We wish him luck with this new venture, and we’re looking forward to future episodes.

One of the best things about GoPro and similar sports cameras is their ability to go just about anywhere and show things we normally don’t get to see. We’re thinking of those gorgeous slo-mo selfies of surfers inside a curling wave, or those cool shots of a skier powder blasting down a mountain slope. But this is the first time we’ve seen a GoPro mounted inside a car’s tire. The video by the aptly named YouTuber [Warped Perception] shows how he removed the tire from the wheel and mounted the camera, a battery pack, and an LED light in the rim, then remounted the tire. The footage of the tire deforming as it contacts the ground is fascinating but oddly creepy. It sort of reminds us a little of the footage from cameras inside the Saturn V fuel tanks — valuable engineering information to be sure, but forbidden in some way.

How About A Nice Cuppa TEA Laser?

August 9, 2020 by 11 Comments

If lasers are your hobby, you face a conundrum. There are so many off-the-shelf lasers that use so many different ways of amplifying and stimulating light that the whole thing can be downright — unstimulating. Keeping things fresh therefore requires rolling your own lasers, and these DIY nitrogen TEA and dye lasers seem like a fun way to go.

These devices are the work of [Les Wright], who takes us on a somewhat lengthy but really informative tour of transversely excited atmospheric (TEA) lasers. The idea with TEA lasers is that a gas, often carbon dioxide in commercial lasers but either air or pure nitrogen in this case, is excited by a high-voltage discharge across long parallel electrodes. TEA lasers are dead easy to make — we’ve covered them a few times — but as [Les] points out, that ease of construction leads to designs that are more ad hoc than engineered.

In the video below, [Les] presents three designs that are far more robust than the typical TEA laser. His lasers use capacitors made from aluminum foil with polyethylene sheets for dielectric, sometimes with the addition of beautiful “doorknob” ceramic caps too. A spark gap serves as a very fast switch to discharge high voltage across the laser channel, formed by two closely spaced aluminum hex bars. Both the spark gap and the laser channel can be filled with low-pressure nitrogen. [Les] demonstrates the power and the speed of his lasers, which can even excite laser emissions in a plain cuvette of rhodamine dye — no mirrors needed! Although eye protection is, of course.

These TEA lasers honestly look like a ton of fun to build and play with. You might not be laser welding or levitating stuff with them, but that’s hardly the point.

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