A Smarter PSU Converter Leaves The Magic Smoke Inside

May 24, 2018 by Lewin Day 24 Comments

Over the years, computers have become faster, but at the same time, more power hungry as well. Way back around the 386 era, most PCs were using the AT standard for power supplies. Since then, the world moved on to the now ubiquitous ATX standard. Hobbyists working on older machines will typically use these readily available supplies with basic adapters to run old machines, but [Samuel] built a better one.

Most AT to ATX adapters are basic passive units, routing the various power lines where they need to go and tying the right pin high to switch the ATX supply on. However, using these with older machines can be fraught with danger. Modern supplies are designed to deliver huge currents, over 20 A in some cases, to run modern hardware. Conversely, a motherboard from the early 90s might only need 2 or 3A. In the case of a short circuit, caused by damage or a failed component, the modern supply will deliver huge current, often damaging the board, due to the overcurrent limit being set so high.

[Samuel]’s solution is to lean on modern electronics to build an ATX to AT adapter with programmable current protection. This allows the current limit to be set far lower in order to protect delicate boards. The board can be set up in both a “fast blow” and a “slow blow” mode to suit various working conditions, and [Samuel] reports that with alternative cabling, it can also be used to power up other old hardware such as Macintosh or Amiga boards. The board is even packed with extra useful features like circuitry to generate the sometimes-needed -5V rail. It’s all programmed through DIP switches and even has an OLED display for feedback.

It’s an adapter that could save some rare old hardware that’s simply irreplaceable, and for that reason alone, we think it’s a highly important build. We’ve talked about appropriate fusing and current limiting before, too – namely, with LED strips.

Spared No Expense: Cloning The Jurassic Park Explorer

May 22, 2018 by Tom Nardi 53 Comments

While you’d be hard pressed to find any serious figures on such things, we’d wager there’s never been a vehicle from a TV show or movie that has been duplicated by fans more than the Staff Jeeps from Jurassic Park. Which is no great surprise: not only do they look cool, but it’s a relatively easy build. A decent paint job and some stickers will turn a stock Wrangler into a “JP Jeep” that John Hammond himself would be proud of.

While no less iconic, there are far fewer DIY builds of the highly customized Ford Explorer “Tour Vehicles”. As a rather large stretch of the film takes place within them, the interiors were much more detailed and bears little resemblance to the stock Explorer. Building a truly screen accurate Jurassic Park Tour Vehicle was considered so difficult that nobody has pulled it off since the movie came out in 1993. That is until [Brock Afentul] of PropCulture decided to take on the challenge.

In an epic journey spanning five years, [Brock] has created what he believes is the most accurate Jurassic Park Tour Vehicle ever produced; and looking at the side by side shots he’s done comparing his Explorer to the ones from the movie, it’s hard to disagree. A massive amount of work went into the interior, leaving essentially nothing untouched. While previous builds have tried to modify the stock dashboard to look like the one from the movie, he built a completely new dash from MDF and foam and coated it in fiberglass. The center console featuring the large display was also faithfully reproduced from the movie, and runs screen accurate animations, maps, and tour information. The seats also had to be replaced, multiple times in fact, as he had a considerable amount of trouble getting somebody to upholster them to his standards.

But perhaps the most difficult component of all was the clear acrylic roof bubble. These were critical to filming the movie, as they not only let the viewer see down into the Tour Vehicles but also let the characters see out during the iconic tyrannosaurus attack. But because the roof bubble was created only for the movie and never existed as a real aftermarket product, it usually gets ignored in Tour Vehicle builds. It’s simply too difficult to produce for most people. The omission of the bubble was always considered a case of artistic license; in the same way nobody expects a replica DeLorean from Back to the Future to actually fly or travel through time.

But [Brock] wanted to take his Tour Vehicle all the way, so he partnered up with a local glass shop that let him rent time in their oven so he could heat up acrylic sheets. Once heated to the appropriate temperature, they could be removed and wrapped around a mold to make the bubble. The process took weeks to perfect, but in the end he and a few friends got the hang of it and were able to produce a gorgeous roof bubble that they fitted to the already very impressive Explorer.

While previous Jurassic Park Tour Vehicle replicas were unquestionably awesome, this build really does take it to the next level. Short of equipping the garage with a movie-accurate super computer, it’s hard to see how the bar can get any higher.

A Parallel Port Synthesiser For Your DOS PC

May 22, 2018 by Jenny List 12 Comments

It is a great shame that back in the days when a typical home computer had easy low-level hardware access that is absent from today’s machines, the cost of taking advantage of it was so high. Professional PCBs were way out of reach of a home constructor, and many of the integrated circuits that might have been used were expensive and difficult to source in small quantities.

Here in the 21st century we have both cheap PCBs and easy access to a wealth of semiconductors, so enthusiasts for older hardware can set to work on projects that would have been impossible back in the day. Such an offering is [Serdef]’s Tiny Parallel Port General MIDI Synthesizer for DOS PCs, a very professionally produced synth that you might have paid a lot of money to own three decades ago.

At its heart is a SAM2695 synthesiser chip, and the board uses the parallel port as an 8-bit I/O port. The software side is handled by a TSR (a Terminate and Stay Resident driver loaded at startup, for those of you who are not DOS aficionados), and there are demonstrations of it running with a few classic games.

If the chip used here interests you, you might like to look at a similar project for an Arduino. The Kickstarter we covered is now long over, but you can also find it on GitHub.

Wireless Headphone Hack Dangles Batteries Like Earrings

May 21, 2018 by Tom Nardi 10 Comments

Koss Porta Pro headphones are something of a rarity in the world of audio gear: they’re widely regarded as sounding great, but don’t cost an exorbitant amount of money. Since the line was introduced in 1984, they’ve been the go-to headphones for those who don’t subscribe to the idea that you should have to take out a loan from the bank just to enjoy your music.

[Jake Bickhard] is a confirmed Porta Pro disciple, owning enough pairs of them that he’s cagey about confirming how many are actually kicking around his home. The only thing he doesn’t like about them is the fact that they’re wired. As it happens, Koss just recently came out with a Bluetooth version of the venerable headphones. But he thought he could do just as well combining a pair of his with a water damaged pair of Bluetooth earbuds he had lying around.

The Porta Pros are easy to take apart, and removing the old wire was no problem. He then cut the “buds” on the Bluetooth earbuds he had, with the intention of just striping the wires and soldering it up to the pads on the Porta speakers. But things didn’t quite go as expected.

What [Jake] hadn’t realized was that the battery for the Bluetooth earbuds wasn’t in the main housing, the power comes from a tiny battery inside each bud. That meant he needed to keep the batteries connected even though the Porta Pro obviously doesn’t have a spot to mount them. In the future he says he’ll address the issue properly, but for now the two batteries hang from the headphones: making it look like he’s wearing the world’s ugliest earrings. But at least he’s happy with the performance of the finished modification, saying they’re even louder now than when they were when wired.

This is a perfect project if you’re cursed with a mobile device that had enough “courage” to take the headphone jack away from you. Though you might first want to study the fine art of soldering headphone wires.

Ditch The Tapes, Put An Android In Your Deck

May 21, 2018 by Tom Nardi 44 Comments

While we here at Hackaday never question why an individual took on a particular project, it surely doesn’t stop our beloved readers from grabbing their pitchforks and demanding such answers in the comments. Perhaps no posts generate more of this sort of furore than the ones which feature old audio gear infused with modern hardware. In almost every case the answer is the same: the person liked the look and feel of vintage hardware, but didn’t want to be limited to antiquated media.

That sentiment is perhaps perfectly personified by the TapeLess Deck Project, created by [Artur Młynarz]. His creations combine vintage cassette decks with an Android phone small enough to fit behind the tape door. An Android application which mimics the look of a playing tape, complete with “hand written” track info, completes the illusion.

The output from the phone is tied into the deck where the audio signal from the tape head would have been, so the volume controls and VU meters still work as expected. Watching the meters bounce around while the animated “tape” plays on the screen really does look incredibly slick, though the effect is somewhat hindered by the fact the physical playback controls don’t seem to be implemented. Incidentally, the whole experience works better if the plastic window on the tape door is removed; that way you can utilize the touch and swipe interface [Artur] has in the software.

We’ve seen previous attempts to modernize the audio cassette experience, but they’ve tended to be more of a novelty than anything. But these decks are nice enough that you can like them non-ironically. Though if we’re talking about portable tape players, there’s only room for one in our cold mechanical hearts.

[Thanks to Nikolai for the tip]

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Prop WWII Machine Gun Courtesy Of Home Depot

May 16, 2018 by Tom Nardi 7 Comments

There’s perhaps nothing worse than working on a project and realizing you don’t have the part you need to complete it. You look through all your stuff twice, maybe three times, on the off chance it’s hiding somewhere. Perhaps even reach out to a few nearby friends to see if they might have something you can use. Forget local stores, what you need is so specific that nobody’s going to keep it in stock. You’re stuck, and now everything has to be put on hold.

That’s precisely what happened to [Nathan Cragun] recently. He needed a Japanese Type 96 Light Machine Gun for a particular scene in the independent World War II film he’s working on, and couldn’t find one anywhere. Out of options, he ended up building a replica with parts from the hardware store. OK, so it isn’t exactly like being short a passive component or two on that new PCB you’re putting together. But while we can’t say a project of ours has ever been short a 70+ year old Japanese machine gun, we can definitely relate to the feeling.

To start his build, [Nathan] printed out a full size diagram of the Type 96 and starting placing PVC pipes on top of it to get a sense for how it would all come together. Once the basic tubular “skeleton” of the weapon was completed, he moved on to cutting the rest of the parts out of EVA foam.

The major pieces that needed to be made were the stock and receiver, but even small details like the spiral ribbing on the barrel and the sights were created to scale using pieces of foam. In a particularly nice touch, [Nathan] even made the magazine removable. If we had to guess, some Japanese soldiers will be shown reloading the weapon onscreen for added authenticity.

The important thing to remember with a filming prop like this is that it doesn’t need to look perfect, just close. It might be used in the background, or seen only for a second during a fast pan. Even in professionally produced TV and movies, many of the props are little more than carved foam. With the excellent job [Nathan] did painting and weathering this build, we have no doubt it will look completely believable in the final production.

We’re no strangers to prop builds here at Hackaday, but they are generally of the science fiction or video game variety, so a historical build is a nice change of pace.

Lucky Cat POV Display Ditches The Waving And Windmills Out Of Control

May 15, 2018 by Richard Baguley 10 Comments

If you’ve been in a Japanese restaurant, you’ve probably seen a maneki-neko, the lucky cat charm, where a cat welcomes you with a beckoning arm. It’s considered to bring good luck, but we’re not sure if [Martin Fitzpatrick] is pushing his luck with this Lucky Cat POV display. He hacked one of the figurines so the arm forms a persistence of vision (POV) display, where blinking LEDs on the paw create a dot-matrix style display.

Inside the hapless neko is a Wemos D1, motor driver, and a few other components that turn the cat into a working display. The five LEDs he attached to the paw are wide enough to display 5×7 characters. The tricky part in the mechanical design is getting signals from a stationary base to a spinning arm(ature). In this case it was easily solved with a 6-wire slip ring from Adafruit. [Martin] revs the lucky cat up using a brushed DC motor and a couple of gears.

The ESP8266 is running MicroPython — the combination should make this a snap to hook into any web service API you want to display your own messages. Right now the arm doesn’t have positional awareness so the message isn’t locked in a single position like it would be if a hall effect sensor was used. But [Martin] says there’s plenty of room left inside the cat and a future upgrade could include stashing the batteries inside for a cordless, all-in-one build. If he takes that on it’s a perfect time to add some type of shaft encoding as well.

Check the Lucky Cat showing off in the clip after the break.

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