The Right Equipment Makes A Difference For Digital Oscilloscope Music

July 29, 2023 by Dan Maloney 4 Comments

We all love our cheap digital oscilloscopes, and with good reason. But if there’s one place where analog scopes still shine, it’s anywhere you need X-Y mode. Digitally sampling the inputs and mapping them on the screen as discrete points just isn’t the same as steering an electron beam around a CRT, making X-Y mode work on digital scopes — at least the affordable ones — somewhat lacking.

Thankfully, nobody told [Mark Hughes] that his digital scope would make a lousy X-Y display, so he just plunged ahead and figured out how to make it work anyway. The results are actually pretty good, but it took some doing. His setup begins with OsciStudio, an application built to take 3D shapes and animations and turn them into oscilloscope music. The output from that is piped to a USB sound card; [Mark] used a PreSonus Studio 26c, an adapter with DC-coupled inputs, which he found to be critical to getting good images. Also important was a USB isolator and good-quality cables, which greatly reduced jitter and made the image much more stable.

DC-coupled

AC-coupled

Displaying the image was as easy as connecting the left and right outputs from the sound card to the two scope inputs — [Mark] used a Keysight EDUX1052G — and setting it to X-Y mode. It took a fair amount of fiddling to get as far as he did, but we think the results speak for themselves. As for the sounds made by these images, he says it’s a bit like a hung sound card when a computer blue-screens. So, yeah — not exactly musical, but still an interesting way to have some fun with your digital scope.

Magnetic Gearbox, Part 2: Axial Flux Improves Performance

July 27, 2023 by Dan Maloney 13 Comments

The number of interesting and innovative mechanisms that 3D printing has enabled always fascinates us, and it’s always a treat when one of them shows up in our feeds. This axial flux magnetic gearbox is a great example of such a mechanism, and one that really makes you think about possible applications.

The principles of [Retsetman]’s gearbox are simple for anyone who has ever played with a couple of magnets to understand, since it relies on that powerful attractive and repulsive force you feel when magnets get close to each other. Unlike his previous radial flux gearbox, which used a pair of magnet-studded cylindrical rotors nested one inside the other, this design has a pair of disc-shaped printed rotors that face each other on aligned shafts. Each rotor has slots for sixteen neodymium magnets, which are glued into the slots in specific arrangements of polarity — every other magnet for the low-speed rotor, and groups of four on the high-speed rotor. Between the two rotors is a fixed flux modulator, a stator with ten ferromagnetic inserts screwed into it.

In operation, which the video below demonstrates nicely, the magnetic flux is coupled between the rotors by the steel inserts in the stator so that when one rotor moves, the other moves at a 4:1 (or 1:4) ratio in the opposite direction. [Retsetman] got the gearbox cranked up to about 8,500 RPM briefly, but found that extended operation at as little as 4,000 RPM invited disaster not due to eddy current heating of the inserts or magnets as one might expect, but from simple frictional heating of the rotor bearings.

Torque tests of the original gearbox were unimpressive, but [Retsetman]’s experiments with both laminated stator inserts and more powerful magnets really boosted the output — up to a 250% improvement! We’d also like to see what effect a Halbach array would have on performance, although we suspect that the proper ratios between the two rotors might be difficult to achieve.

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Adding Two Axes Makes CNC Router More Than The Sum Of Its Parts

July 26, 2023 by Dan Maloney 20 Comments

The problem with building automated systems is that it’s hard to look at any problem and not see it in terms of possible automation solutions. Come to think of it, that’s probably less of a bug and more of a feature, but it’s easy to go overboard and automate all the things, which quickly becomes counterproductive in terms of time and money.

If you’re clever, though, a tactical automation solution can increase your process efficiency without breaking the budget. That’s where [Christopher Helmke] seems to have landed with this two-axis add-on fixture for his CNC router. The rig is designed to solve the problem of the manual modification needed to turn off-the-shelf plastic crates into enclosures for his line of modular automation components, aspects of which we’ve featured before. The crates need holes drilled in them and cutouts created in their sides for displays and controls. It’s a job [Christopher] tackled before with a drill and a jigsaw, with predictable results.

To automate the job without going overboard, [Christopher] came up with a tilting turntable that fits under the bed of the CNC router and sticks through a hole in the spoil board. The turntable is a large, 3D printed herringbone gear driven by a stepper and pinion gear. A cheap bearing keeps costs down, while a quartet of planetary gears constrain the otherwise wobbly platform. The turntable also swivels 90 degrees on a herringbone sector gear; together, the setup adds pitch and roll axes to the machine that allow the spindle access to all five sides of the crates.

Was it worth the effort? Judging by the results in the video below, we’d say so, especially given the number of workpieces that [Christopher] has to process. Add in the budget-conscious construction that doesn’t sacrifice precision too much, and this one seems like a real automation win.

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ChatGPT, The Worst Summer Intern Ever

July 26, 2023 by Dan Maloney 71 Comments

Back when I used to work in the pharma industry, I had the opportunity to hire summer interns. This was a long time ago, long enough that the fresh-faced college students who applied for the gig are probably now creeping up to retirement age. The idea, as I understood it, was to get someone to help me with my project, which at the time was standing up a distributed data capture system with a large number of nodes all running custom software that I wrote, reporting back to a central server running more of my code. It was more work than I could manage on my own, so management thought they’d take mercy on me and get me some help.

The experience didn’t turn out quite like I expected. The interns were both great kids, very smart, and I learned a lot from them. But two months is a very tight timeframe, and getting them up to speed took up most of that time. Add in the fact that they were expected to do a presentation on their specific project at the end of the summer, and the whole thing ended up being a lot more work for me than if I had just done the whole project myself.

I thought about my brief experience with interns recently with a project I needed a little help on. It’s nothing that hiring anyone would make sense to do, but still, having someone to outsource specific jobs to would be a blessing, especially now that it’s summer and there’s so much else to do. But this is the future, and the expertise and the combined wisdom of the Internet are but a few keystrokes away, right? Well, maybe, but as you’ll see, even the power of large language models has its limit, and trying to loop ChatGPT in as a low-effort summer intern leaves a lot to be desired.

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Selectric Typewriter Goes From Trash Can To Linux Terminal

July 25, 2023 by Dan Maloney 19 Comments

If there’s only lesson to be learned from [alnwlsn]’s conversion of an IBM Selectric typewriter into a serial terminal for Linux, it’s that we’ve been hanging around the wrong garbage cans. Because that’s where he found the donor machine for this project, and it wasn’t even the first one he’s come across in the trash. The best we’ve ever done is a nasty old microwave.

For being a dumpster find, the Selectric II was actually in pretty decent shape. The first couple of minutes of the video after the break show not only the minimal repairs needed to get the typewriter back on its feet, but also a whirlwind tour of the remarkably complex mechanisms that turn keypresses into characters on the page. As it turns out, knowing how the mechanical linkages work is the secret behind converting the Selectric into a teletype, entirely within the original enclosure and with as few modifications to the existing mechanism as possible.

Keypresses are mimicked with a mere thirteen solenoids — six for the “latch interposers” that interface with the famous whiffletree mechanism that converts binary input to a specific character on the typeball, and six more that control thinks like the cycle bail and control keys. The thirteenth solenoid controls an added bell, because every good teletype needs a bell. For sensing the keypresses — this is to be a duplex terminal, after all — [alnwlsn] pulled a page from the Soviet Cold War fieldcraft manual and used opto-interrupters to monitor the positions of the latch interposers as keys are pressed, plus more for the control keys.

The electronics are pretty straightforward — a bunch of MOSFETs to drive the solenoids, plus an AVR microcontroller. The terminal speaks RS-232, as one would expect, and within the limitations of keyboard and character set differences over the 50-odd years since the Selectric was introduced, it works fantastic as a Linux terminal. The back half of the video is loaded with demos, some of which aptly demonstrate why a lot of Unix commands look the way they do, but also some neat hybrid stuff, like a ChatGPT client.

Hats off to [alnwlsn] for tackling a difficult project while maintaining the integrity of the original hardware.

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CircuitPython Happenings Hack Chat With Adafruit

July 24, 2023 by Dan Maloney 29 Comments

Join us on Wednesday, July 26 at noon Pacific for the CircuitPython Happenings Hack Chat with The folks from Adafruit!

It’s always a party when the good folks from Adafruit stop by the Hack Chat, and we expect no less than that this time around. It’s hard to predict where the conversation will go when [LadyAda], [pt], and [Scott] roll in, but we strongly suspect it’ll center on what’s new in the world of CircuitPython.

We’ve heard that they’ve got some cool stuff going on with CircuitPython on the RP2040, which just might lead to a Python-based fix for the current Bus Pirate supply chain problem. It’ll be a swashbucklingly good time, so make sure you stop by.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, July 26 at 12:00 PM Pacific time. If time zones have you tied up, we have ahandy time zone converter.

Hackaday Links: July 23, 2023

July 23, 2023 by Dan Maloney 4 Comments

It may be midwinter in Perth, but people still go to the beach there, which led to the surprising discovery earlier this week of what appears to be a large hunk of space debris. Local authorities quickly responded to reports of a barnacle-encrusted 2.5-m by 3-m tank-like object on the beach. The object, which has clearly seen better days, was described as being made of metal and a “wood-like material,” which on casual inspection is clearly a composite material like Kevlar fibers in some sort of resin. Local fire officials teamed up with forensic chemists to analyze the object for contamination; finding none, West Australia police cordoned off the device to keep the curious at bay. In an apparently acute case of not knowing how the Internet works, they also “urge[d] everyone to refrain from drawing conclusions” online, which of course sent the virtual sleuths into overdrive. An r/whatisthisthing thread makes a good case for it being part of the remains of the third stage of an Indian Polar Satellite Launch Vehicle (PSLV); reentry of these boosters is generally targeted at the East Indian Ocean for safe disposal, but wind and weather seem to have brought this artifact back from the depths.

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