Ah, the 1990s. It was a simpler time, when the web was going to be democratic and decentralised, you could connect your Windows 95 PC to the internet without worrying much about it being compromised, and freely download those rave music MP3s. Perhaps you had a Global Hypercolor T-shirt and spent a summer looking like the sweaty idiot you were, and it’s certain you desperately squinted at a magic eye image in a newspaper (remember newspapers?) trying to see the elephant or whatever it was. If you’d like to relive that experience, then [Dave Richeson] has a magic eye image generator for Microsoft Excel.
Unfortunately a proportion of the population including your scribe lack the ability to see these images, a seemingly noise-like pattern of dots on the page computationally generated to fool the visual processing portion of your brain to generate a 3D image. The Excel sheet allows you to create the images, but perhaps most interesting is the explanation of the phenomenon and mathematics which go along with it. Along with a set of test images depicting mathematical subjects, it’s definitely worth a look.
You can download a template and follow the instructions, and from very limited testing here we can see that LibreOffice doesn’t turn its nose up at it, either. Give it a go, and learn afresh the annoyance of trying to unfocus your eyes.
The widely quoted carrot factoid that the vegetable’s orange colour is the result of patriotic Dutch farmers breeding them that way may be an urban myth, but it’s certainly true that they can pass an audio signal in a time of need. [Julian Krause] follows up on a Reddit meme of a carrot being used to join two phono plugs, and appears to find the organic interconnect to be of good quality.
We had to admit a second look at a calendar to be sure that it’s not April 1st, but while his manner is slightly tongue in cheek it seems he’s really characterising the audio performance of a carrot. What he finds is a bit of attenuation, some bass cut, and an intrusion of RF interference pickup, but surprisingly, not a bad distortion figure.
Of course, we’re guessing the real point of the exercise is to poke fun at the world of excessive hi-fi equipment, something we’ve been only too glad to have a go at ourselves from time to time. But if the tests are to be taken at face value it seems that in a pinch, a carrot will do as a means to hook together line level audio cables, no doubt lending a sweet and crunchy overtone to the result. The video is below the break, for your entertainment.
A good source of hackable home automation parts has come for a while in the form of inexpensive modules offered by large retailers such as Lidl, or IKEA. They’re readily available and easy to play with, they work with open source hubs, so what’s not to like! As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown, it’s as you might expect, a passive infrared sensor (PIR) sensor coupled with a Zigbee interface.
Inside the ultrasonic welded case is a small PCB and a Fresnel lens on the inside of the top cover, and a small PCB for the electronics. We applaud the use of a Swiss Army knife can opener as a spudger. The interesting part comes in identifying the individual components: the Silicon Labs EFR32MG21 SoC is easy enough, but another mystery 8-pin chip is more elusive. The part number suggests an Analog Devices op-amp for signal conditioning the PIR output, but the pinout seems not to support it and from here we think it’s too expensive a part for a budget item like this.
There’s a handy header for talking to the SoC, which we’d love to report is open and ready to be hacked, but we’re not getting too optimistic. Even if not hackable though, we’re guessing many of you find uses for these things.
It’s not often that the passing of a medium sized company on an industrial estate on a damp and soggy former airfield in southern England is worthy of a Hackaday mention, but the news of hypersonic propulsion company Reaction Engines ceasing trading a few weeks ago is one of those moments that causes a second look. Their advanced engine technology may have taken decades to reach the point of sustainable testing, but it held the promise of one day delivering true spaceplanes able to take off from a runway and fly to the edge of the atmosphere before continuing to orbit. It seems their demise is due to a failure to secure more funding.
We’ve written about their work more than once in the past, of their hybrid engines and the development of the advanced cooling system required to deliver air to a jet engine working at extreme speeds. The rights to this tech will no doubt survive the company, and given that its origins lie in a previously canceled British Aerospace project it’s not impossible that it might return. The dream of a short flight from London to Sydney may be on hold for now then.
Aluminium drinks cans make a great source of thin sheet metal which can be used for all manner of interesting projects, but it’s safe to say that retrieving a sheet of metal from a can is a hazardous process. Cut fingers and jagged edges are never far away, so [Kevin Cheung]’s work in making an easy can cutter is definitely worth a look.
Taking inspiration from a rotary can opener, he uses a pair of circular blades in an adjustable injection moulded plastic frame. If you’ve used a pipe cutter than maybe you are familiar with the technique, as the blade rotates round the can a few times it slowly scores and cuts through the metal. Doing the job at both ends of the can reveals a tube, which cna be then cut with scissors and flattened to make a rectangular metal sheet. Those edges are probably sharp, but nothing like the jagged finger-cutters you’d get doing the same by hand. The full video can be seen below the break, and the files to 3D print the plastic parts of the cutter can be found at the bottom of a page describing the use of cans to make a shingle roof.
When we saw [Max.K]’s automatic NiMh battery charger float past in the Hackaday tips line, it brought to mind a charger that might be automatic in the sense that any modern microcontroller based circuit would be; one which handles all the voltages and currents automatically. The reality is far cooler than that, a single-cell charger in which the automatic part comes in taking empty cells one by one from a hopper on its top surface and depositing them charged in a bin at the bottom.
Inside the case is a PCB with an RP2040 that controls the whole shop as well as the charger circuitry. A motorised cam with a battery shaped insert picks up a cell from the bin and moves it into the charger contacts, before dumping it into the bin when charged. What impresses us it how slick this device is, it feels like a product rather than a project, and really delivers on the promise of 3D printing. We’d want one on our bench, and after watching the video below the break, we think you will too.
The world of the overclocker contains many arcane tweaks to squeeze the last drops of performance from a computer, many of which require expert knowledge to understand. Happily for Raspberry Pi 5 owners the Pi engineers have come up with a set of tweaks you don’t have to be an overclocker to benefit from, working on the DRAM timings to extract a healthy speed boost. Serial Pi hacker [Jeff Geerling] has tested them and thinks they should be good for as much as 20% boost on a stock board. When overclocked to 3.2 GHz, he found an unbelievable 32% increase in performance.
We’re not DRAM experts here at Hackaday, but as we understand it they have been using timings from the Micron data sheets designed to play it safe. In consultation with Micron engineers they were able to use settings designed to be much faster, we gather by monitoring RAM temperature to ensure the chips stay within their parameters. Best of all, there’s no need to get down and dirty with the settings, and they can be available to all with a firmware update. It’s claimed this will help Pi 4 owners to some extent as well as those with a Pi 5, so even slightly older boards get some love. So if you have a Pi 5, don’t wait for the Pi 6, upgrade today, for free!
Many Hackaday readers have an interest in retro technology, but we are not the only group who scour the flea markets. Alongside us are the collectors, whose interest is as much cultural as it is technological, and who seek to preserve and amass as many interesting specimens as they can. From this world comes [colectornet], with a video that crosses the bridge between our two communities, examining the so-called transistor wars of the late 1950s and through the ’60s. Just as digital camera makers would with megapixels four or five decades later, makers of transistor radios would cram as many transistors as they could into their products in a game of one-upmanship.
A simple AM transistor radio can be made with surprisingly few components, but for a circuit with a reasonable performance they suggest six transistors to be the optimal number. If we think about it we come up with five and a diode, that’s one for the self-oscillating mixer, one for IF, an audio preamplifier, and two for the audio power amplifier, but it’s possible we’re not factoring in the relatively low gain of a 1950s transistor and they’d need that extra part. In the cut-throat world of late ’50s budget consumer electronics though, any marketing ploy was worth a go. As the price of transistors tumbled but their novelty remained undimmed, manufacturers started creating radios with superfluous extra transistors, even sometimes going as far as to fit transistors which served no purpose. Our curious minds wonder if they bought super-cheap out-of-spec parts to fill those footprints.
The video charts the transistor wars in detail, showing us a feast of tiny radios, and culminating in models which claim a barely credible sixteen transistors. In a time when far more capable radios use a fraction of the board space, the video below the break makes for a fascinating watch.
Making a microcontroller speak to a VGA monitor has been a consistent project in our sphere for years, doing the job for which an IBM PC of yore required a plug-in ISA card. Couldn’t a microcontroller talk to a VGA card too? Of course it can, and [0xmarcin] is here to show how it can be done with an Arduino Mega.
The project builds on the work of another similar one which couldn’t be made to work, and the Trident card used couldn’t be driven in 8-bit ISA mode. The web of PC backwards compatibility saves the day though, because many 16-bit ISA cards also supported the original 8-bit slots from the earliest PCs. The Arduino is fast enough to support the ISA bus speed, but the card also needs the PC’s clock line to operate, and it only supports three modes: 80 x 25, 16 colour text, 320 x 200, 256 colour graphics, and 640 x 480, 16 colour graphics.
Looking at this project, it serves as a reminder of the march of technology. Perhaps fifteen years or more ago we’d have been able to lay our hands on any number of ISA cards to try it for ourselves, but now eight years after we called the end of the standard, we’d be hard placed to find one even at our hackerspace. Perhaps your best bet if you want one is a piece of over-the-top emulation.
Back when CD-Rs were the thing, there were CD burner drives which would etch images in the unoccupied areas of a CD-R. These so-called LightScribe drives were a novelty of which most users soon tired, but they’re what’s brought to our mind by [dbalsom]’s project. It’s called PNG2disk, and it does the same job as LightScribe, but for floppies. There’s one snag though; the images are encoded in magnetic flux and thus invisible to the naked eye. Instead, they can be enjoyed through a disk copying program that shows a sector map.
The linked GitHub repository has an example, and goes in depth through the various options it supports, and how to view images in several disk analysis programs. This program creates fully readable disks, and can even leave space for a filesystem. We have to admit to being curious as to whether such an image could be made physically visible using for example ferrofluid, but we’d be the first t admit to not being magnetic flux experts.
The games consoles which came out of Japan in the 1980s are the stuff of legend, with the offerings from Nintendo and Sega weaving themselves into global popular culture. Most of us can recite a list of the main players in the market, but how many of us would have Epoch and their Super Cassette Vision on that list? [Nicole Express] is here with a look at this forgotten machine which tried so hard and yet missed the target when competing with the NES or Master System.
Before the arrival of the Sega and Nintendo cartridge based systems, one of the better known Japanese consoles was the Epoch Cassette Vision. This was something of a hybrid between single-game TV games and an Atari 2600 style computing device for games, in that it used pre-programmed microcontrollers in its cartridges rather than the ROMs of the 2600. For the late-70s gamer this was still hot stuff, but by 1983 as the Master System and NES hove into view it was definitely past its best. Epoch’s response for 1984 was the Super Cassette Vision, a much more conventional 8-bit console with on the face of it some respectable graphics and sound hardware.
The article looks at the console’s capabilities in detail, highlighting the multi-colored sprites and smooth sprite movement, but also the tilemap limitations and the somewhat awful sound chip shared with handheld games and sounding very much like it. Coupled with its inferior controllers and TV game style aesthetic, it’s not difficult to see why it would be the last console from this manufacturer.
If forgotten consoles are your thing, have a read about the Fairchild Channel F, the machine that gave us console cartridges.
There can be few among those of us who produce printed circuit boards, who have not at some point placed a component the wrong way round, or with the wrong footprint. Usually this can be rectified with a bit of rework and a fresh board spin, but just occasionally these mishaps make it into the wild undetected. It seems nobody is immune, as [Doug Brown] is here to tell us with a tale of an Apple product with a misplaced capacitor.
The LC series of Macs came out through the early 1990s, and their pizza-box style cases could be found slowly turning yellow in universities and schools throughout that decade. Of them there was a persistent rumor of the LCIII had a misplaced capacitor, so when he received an unmodified original machine he took a look. The investigation is quite simple, but revealing — there are three power supply rails and one of the capacitors does have a significant leak.
The explanation is simple enough, the designer had placed a capacitor on each rail, with its negative side to the ground plane, but one of the rails delivers -5 volts. Thus the capacitor is the wrong way round, and must have failed pretty early in the lifetime of each LCIII. We’re curious then since so many of them went through their lives without the component being replaced, how the circuit remained functional. We’re guessing that there were enough other capacitors in the -5 volt line to provide enough smoothing.
If you were to walk into most of the world’s hackerspaces, it’s likely that the most frequent big-ticket tool you’ll find after a 3D printer is a laser cutter. A few years ago that would inevitably been one of the ubiquitous blue Chinese-made K40 machines, but here in 2024 it’s become common to see something far more sophisticated. For all that, many of us are still laser cutter noobs, and for us [Dominic Morrow] gave a talk at last summer’s EMF Camp in the UK entitled “Getting Started In Laser Cutting“. [Dominic] is a long-term laser cutting specialist who now works for Lightburn, so he’s ideally placed to deliver this subject.
It’s fair to say that this is an overview in the time available for a hacker camp talk rather than an in-depth piece, so he takes the approach of addressing people’s misconceptions and concerns about cutters. Perhaps the most important one he addresses is the exhaust, something we’ve seen a few in our community neglect in favor of excessive attention to laser cooling or other factors. An interesting one for us though was his talking about the cheaper diode lasers, having some insight into this end of the market is valuable when you have no idea which way to go.
A common part used to create a high voltage is a CRT flyback transformer, having been a ubiquitous junk pile component. So many attempts to use them rely on brute force, with power transistors in simple feedback oscillators dropping high currents into hand-wound primaries, so it’s refreshing to see a much more nuanced approach from [Alex Lungu]. His flyback driver board drives the transformer as it’s meant to be used, in flyback mode relying on the sudden collapse of a magnetic field to generate an output voltage pulse rather than simply trying to create as much field as possible. It’s thus far more efficient than all those free running oscillators.
On the PCB is a UC3844 switch mode power supply controller driving the transformer at about 25 kHz through an IGBT. We’d be curious to know how closely the spec of the transformer is tied to the around 15 kHz it would have been run at in a typical TV, and thus what frequency would be the most efficient for it. The result as far as we can see it a stable and adjustable high voltage source with out all the high-current and over heating, something of which we approve.
Need to understand more about free running versus flyback? Read on.
There was a time when no self-respecting electronics engineer would build a big project without at least one panel meter. They may be a rare part here in 2024, but we find ourselves reminded of them by [24Eng]’s project. It’s a 3D printed housing for one of those common small OLED displays, designed to be mounted on a panel with just a single round hole. Having had exactly this problem in the past trying to create a rectangular hole, we can immediately see the value in this.
It solves the problem by encasing the display in a printed shell, and passing a coarsely threaded hollow cylinder behind it for attachment to the panel and routing wires. This is where we are reminded of panel meters, many of which would have a similar sized protrusion on their rear housing their mechanism.
A conventional tube amplifier has a circuit whose fundamentals were well in place around a hundred years ago, so there are few surprises to be found in building one today. Nevertheless, building one is still a challenge, as [Mike Freda shows us with a stereo amplifier in the video below the break.
The tubes in question are the 12AU7 double triode and 6L6 tetrode, in this case brand new PSVANE parts from China. The design is a very conventional single-ended class A circuit, with both side of the double triode being used for extra gain driving the tetrode. The output uses a tapped transformer with the tap going to the other grid in the tertode, something we dimly remember as being an “ultra-linear” circuit.
There’s an element of workshop entertainment in the video, but aside from that we think it’s the process of characterising the amp and getting its voltages right which is the take-away here. It’s not something many of us do these days, so despite the apparent simplicity of the circuit it’s worth a look.
Over the years we’ve featured many projects which attempt to replicate the feel of physical media when playing music. Usually this involves some kind of token representation of the media, but here’s [Bas] with a different twist (Dutch language, Google Translate link). He’s using the CDs themselves in their cases, identifying them by their barcodes.
At its heart is a Raspberry Pi Pico W and a barcode scanner — after reading the barcode, the Pi calls Discogs to find the tracks, and then uses the Spotify API to find the appropriate links. From there, Home Assistant forwards them along to a smart speaker for playback. As a nice touch, [Bas] designed a 3D printed holder for the electronics which makes the whole thing a bit neater to use.
It’s with sadness that we note the passing of Thomas E. Kurtz, on November 12th. He was co-inventor of the BASIC programming language back in the 1960s, and though his creation may not receive the attention in 2024 that it would have done in 1984, the legacy of his work lives on in the generation of technologists who gained their first taste of computer programming through it.
For the 1980s kids who got beyond this coding masterpiece, BASIC launched many a technology career.
The origins of BASIC lie in the Dartmouth Timesharing System, like similar timesharing operating systems of the day, designed to allow the resources of a single computer to be shared across many terminals. In this case the computer was at Dartmouth College, and BASIC was designed to be a language with which software could be written by average students who perhaps didn’t have a computing background. In the decade that followed it proved ideal for the new microcomputers, and few were the home computers of the era which didn’t boot into some form of BASIC interpreter. Kurtz continued his work as a distinguished academic and educator until his retirement in 1993, but throughout he remained as the guiding hand of the language.
Should you ask a computer scientist their views on BASIC, you’ll undoubtedly hear about its shortcomings, and no doubt mention will be made of the GOTO statement and how it makes larger projects very difficult to write. This is all true, but at the same time it misses the point of it being a readily understandable language for first-time users of machines with very little in the way of resources. It was the perfect programming start for a 1970s or 1980s beginner, and once its limitations had been reached it provided the impetus for a move to higher things. We’ve not written a serious BASIC program in over three decades, but we’re indebted to Thomas Kurtz and his collaborator for what they gave us.
In the iconic 1990s TV series The X Files, David Duchovny’s FBI agent-paranormal investigator Fox Mulder has a poster on his office wall. It shows a flying saucer in flight, with the slogan “I Want To Believe”. It perfectly sums up the dilemma the character faces. And while I’m guessing that only a few Hackaday readers have gone down the full lizard-people rabbit hole, wanting to believe is probably something that a lot of us who love sci-fi understand. It would be a fascinating event for science if a real extraterrestrial craft would show up, so of course we want to believe to some extent, even if we’re not seriously expecting it to appear in a Midwestern cornfield and break out the probes any time soon.
Outside the realm of TV drama and science fiction it’s a sentiment that also applies in more credible situations. Back at the end of the 1980s for example when so-called cold fusion became a global story it seemed as though we might be on the verge of the Holy Grail of clean energy breakthroughs. Sadly we never got our Mr. Fusion to power our DeLorean, and the scientific proof was revealed to be on very weak foundations. The careers of the two researchers involved were irreparably damaged, and the entire field became a byword for junk science. A more recently story in a similar vein is the EM drive, a theoretical reactionless force generator that was promising enough at one point that even NASA performed some research on it. Sadly there were no magic engines forthcoming, so while it was worth reporting on the initial excitement, we’re guessing the story won’t come back.
When evaluating a scientific or technical breakthrough that seems as miraculous as it is unexpected then, of course we all want to believe. We evaluate based on the information we have in front of us though, and we all have a credibility pyramid. There’s nothing wrong with having an interest in fields that are more hope than delivery, indeed almost every technology that powers our world will at some time have to overcome skepticism in its gestation period. Perhaps it’s best to say that it’s okay to have hope, but hope shouldn’t override our scrutiny of the proof. Of course I want a perpetual motion machine, who wouldn’t, but as a fictional engineer once allegedly said, “Ye cannae change the laws of physics”.
An Example Here In 2024
The hydrogen future is very seductive. But does it work? Jóhann Heiðar Árnason, CC BY-SA 3.0.
All this introspection has been brought to the fore for me by something very much in the present, the so-called hydrogen economy. It’s difficult to ignore our climate emergency, and among the energy solutions aimed at doing something about it, hydrogen seems very promising.
It’s really easy to make from water by electrolysis, there are several ways to turn it into useful energy, and the idea is that if you can store it for later use you’re on to a winner. We’ve seen hydrogen cars, trucks, aircraft, heavy machinery, trains, and even the gas supplanting methane in the domestic grid, so surely the hydrogen future is well under way, right?
Sadly not, because as many a pilot project has shown, it’s difficult to store or transport, it makes many existing metal fittings brittle, and the environmental benefit is often negated by the hydrogen being generated from higher carbon electrical supplies. We still want to believe, but we can’t claim it’s delivering yet.
Whenever we feature a hydrogen-based story, as for example with this experimental storage tech from Swiss researchers, there is no shortage of comments about all of hydrogen’s shortcomings, and some even accuse us of somehow being the snake-oil salesmen shilling the questionable product. I feel this misses the point, that even though in almost all cases the battery is for now the better option, we cover interesting technology stories regardless of judgements over their eventual success. Hydrogen has enough real science and engineering behind it that its problems might one day be overcome, thus we’d be doing our readers a disservice if we didn’t cover it. There are sometimes newsworthy stories upon which we very much take a credible stand based on opinion, but when it comes to pure tech stories such as a hydrogen vehicle we’re simply reporting on the story because we find it interesting and we think you will too. We don’t know that the breakthrough engineering work won’t occur, but we do know that it hasn’t yet.
So when looking at a piece of technology that’s not delivered on its promise, ask for a moment whether there’s a likely “yet” on the end of the sentence without too much of a suspension of credibility. You might find yourself pleasantly surprised.
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