Unusual 72-Bulb Display Mechanism Found In Vintage Clock

July 30, 2016 by Cameron Coward 33 Comments

It’s hard to beat a vintage clock for something that you can hack, and that your significant other might actually let you display in your home. It’s practical and it’s art all at the same time! But, finding that perfect vintage clock for restoration can be a bit tricky. A crowd favorite is to choose something with intricate mechanisms and gears — the motion of a mechanical display is just so fascinating.

[Gavin] managed to find a clock that is every bit as interesting without any moving parts. The clock uses a unique system of bulbs and screen masks to project each digit of the time onto glass, which creates a pretty cool look you’re not likely to see on other devices. As cheap as LCD and 7-segment displays are these days, it’s hard to imagine a time when an intricate solution like this — using 72 light bulbs — was considered practical.

Of course, what isn’t practical is replacing 72 incandescent bulbs, just to have them start the process of burning out all over again. [Gavin’s] solution to this problem was to replace the incandescent bulbs with LEDs. After getting the color temperature right (to replicate the vintage warm glow), he was able to use a jig system to get the LEDs positioned correctly to project the digits properly.

This certainly isn’t the first time we’ve seen a unique clock design, but there is something intriguing about seeing a design like this that never quite caught on. It’s a little bit of technological history that even your significant other will think is cool.

4-Bit Audio Output Via Voltage Reference

July 30, 2016 by Elliot Williams 18 Comments

[Bruce Land] switched his microprocessor programming class over from Atmel parts to Microchip’s PIC32 series, and that means that he’s got a slightly different set of peripherals to play with. One thing that both chips lack, however is a digital-to-analog converter (DAC). Or do they? (Dun-dun-dun-duuuuhnnnn!)

The PIC part has a programmable, sixteen-level voltage reference. And what is a Vref if not a calibrated DAC? With that in mind, [Bruce] took to documenting its performance and starting to push it far beyond the manufacturer’s intentions. Turns out that the Vref has around 200 kHz of bandwidth. (Who would update a voltage reference 200,000 times per second?)

Anyway, [Bruce] being [Bruce], he noticed that the bits weren’t changing very often in anything more than the least significant bit: audio waveforms, sampled fast enough, are fairly continuous. This suggests using a differential PCM encoding, which knocks the bitrate down by 50% and saves a lot on storage. (Links to all the code for this experiment is inline with his writeup.)

The audio hacks that come out of [Bruce]’s Cornell ECE classes are always a treat. From the lock that you have to sing to open, to chiptunes programmed into an FPGA, there’s something for music fans of all inclinations.

Droolworthy Animatronic Stargate Horus Helmet

July 30, 2016 by Elliot Williams 23 Comments

It’s incredibly likely that, unless you own one of the original movie props, your Stargate Horus helmet is not as cool as [jeromekelty]’s. We say this with some confidence because [jerome] got access to the original molds and put in an incredible amount of time on the animatronics. (See his latest video embedded below.)

Surprisingly, a number of the parts for this amazing piece were bought off the shelf. The irises that open and close they eyes, for instance, were bought on eBay. This is not to downplay the amount of custom design, though. The mechanism that moves the feathers is a sight to see, and there’s a lot of hand-machined metal holding it all together. But the payoff is watching the thing move under remote control. The eye dimming and closing, combined with the head movements, make it look almost alive.

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A Crash Sensor For Delta 3D Printers

July 30, 2016 by Moritz Walter 4 Comments

It doesn’t happen that often, but this is the last time that [Lucas] comes back from hours of unattended 3D printing to find a large portion of plastic spaghetti mess and a partly disassembled Kossel. The crash sensor he designed will now safely halt the printer if it detects that something went wrong during the print.

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Hackaday Prize Entry: Reflectance Transformation Imaging

July 29, 2016 by Brian Benchoff 22 Comments

Reflectance transformation imaging (RTI), or polynomial texture mapping, is a very interesting imaging technique that allows you to capture all the detail of an object. It’s used to take finely detailed pictures of scrawlings on cave walls in archeology, capture every detail of a coin for coin collectors, and to measure the very slight changes in a work of art.

RTI does this by shining light over an object at very particular angles and then using image processing to produce the best image. Despite being only a few LEDs and a bit of software, RTI systems are outrageously expensive. For his Hackaday Prize entry, [leszekmp] is building his own RTI system. It’ll cost about $600, making this the best way for Citizen Scientists to capture the best image possible.

RTI is simply shining light onto an object and taking synchronized pictures of the object from directly above. As you can imagine, putting LEDs in a dome is the obvious solution to this problem, and already [leszekmp] has made three systems that works well on domes up to a meter in diameter. The electronics are as simple as an Arduino shield and a few MOSFETS, and the dome itself is an off the shelf component. It’s a great project that enables better photography, and one of the simplest and best entries we’ve seen for The Hackaday Prize.

The Prettiest Darn Arcade Cabinet You’ll See Today

July 29, 2016 by Cameron Coward 11 Comments

We see an awful lot of arcade cabinets around here, and so it’s pretty unusual for a build to get much more than a second glance. But, this beauty is just too good not to mention. The entire build, named “Ready Player One” as a nod to the engrossing Ernest Cline novel, is detailed in [scoodidabop’s] post on Reddit.

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A One LED Clock

July 29, 2016 by Jenny List 18 Comments

Esoteric clocks are something of a staple among hardware hacker projects. If it can be made to tell the time correctly, even if only twice a day, the chances are someone’s made a clock from it. And if the only person who can read that clock is its creator, so much the better. Universal accessibility is not always a virtue in the world of unusual timepieces.

[Setvir] writes to us with details of his One LED Clock. It’s an Arduino Pro Micro with an RTC module and an LED. That’s all, time is communicated to the world through LED flashes. You might expect therefore that it would use Morse Code, but he’s come up with his own timing communication scheme which does have some merit. Long flashes cover a quarter of the clock face, while short flashes cover individual hours or five-minute segments. He goes into detail on the project page and we can see that once you are used to the scheme it has an elegance to it, but it certainly ticks the essential unreadable-to-the-uninitiated box for an esoteric clock.

We like it though for its simplicity and for the flashing scheme, which once explained is both efficient and easy to read. If you would like to have a go yourself he’s published his code, so go forth and cover the world with baffling single-LED timepieces!

We’ve featured a few minimalist LED clocks before, at least one with a minimal face, and another single-LED offering. But that one used a bi-colour LED, so [Setvir] takes the minimalism crown.