PoE Powers Christmas Lights, But Opens Up So Much More

December 31, 2019 by Jenny List 12 Comments

Addressable LEDs are a staple of homemade Christmas decorations in our community, as is microprocessor control of those LEDs. So at first sight [Glen Akins]’ LED decorated Christmas tree looks pretty enough, but isn’t particularly unusual. But after reading his write-up you’ll discover there’s far more to the project than meets the eye, and learn a lot about the technologies behind it that has relevance far beyond a festive light show.

The decoration is powered exclusively from power-over-Ethernet, with a PIC microcontroller translating Art-Net DMX-over-Ethernet packets into commands for the LED string. The control board is designed from the ground up and includes all the PoE circuitry, and the write-up gives a very thorough introduction to this power source that takes the reader way beyond regarding PoE as simply another off-the-shelf black box. Along the way we see all his code, as well as learn a few interesting tidbits such as the use of a pre-programmed EEPROM containing a unique MAC address.

So if your house has CAT5 wiring and you want an extra dimension to your festive splendour, you’ve officially got a whole year to build your own version. He’s featured here before, with his buzzer to break the Caps Lock habit.

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Flip Phones Are Making A Comeback

December 31, 2019 by Sharon Lin 34 Comments

If you’re the kind of person who hates this new generation of smartphone users and longs for a nostalgic past, you’re not far from the new target demographic for many commercial phone manufacturers. Major phone companies like Motorola and Huawei have been developing foldable versions of conventional smartphone designs, intended to be more versatile while maintaining the same functionality as their less flexible counterparts.

It’s certainly gimmicky, but phones like the Samsung Galaxy Fold, the Motorola Razr, and the Huawei MateX are elegant from an engineering perspective. Developing a seamless interface experience, maximizing surface area for functionality, and maintaining the same nostalgic flip phone aesthetic while making use of familiar smartphone features isn’t an easy design process.

Motorola RAZR hinge shown by CNET’s Patrick Holland during a tour of their labs.

For the Razr, a hinge system that takes up about a third of the phone’s internal space allows the OLED display to have no noticeable binder line. Rather than curving like a piece of paper, it forms a teardrop shape that prevents the screen from creasing and being damaged. Springs and pistons below the surface move small places underneath where the user will be tapping – folded in, the plates slide away. It’s an interesting effect, although as you can see in the banner image, it doesn’t quite achieve optically flat perfection.

In order to ensure that the screen doesn’t overheat as it bends, it is made up of microlayers sandwiched together. To balance weight, the circuits and battery is split into two, operating on each half of the device, an unusual design choice for smartphones. Placement of the array of radios and antennas is also a challenge since they can’t be too close to each other or the processor, which can interfere with signal transmission.

Other devices like the Royale Flexpai are more so proof-of-concepts making use of flexible screens and batteries, rather than capturing the aesthetics of a flip phone generation — but who doesn’t want their smartphone to unfold into a tablet when needed? The future of smartphone technology is looking interesting, and we’ll be sure to see even more iterations of flexible displays in the near future.

Macro Photography With Industrial Lenses

December 31, 2019 by Lewin Day 11 Comments

Line scan cameras are advanced devices used for process inspection tasks in industrial applications. Used to monitor the quality of silicon wafers and other high-accuracy tasks, they’re often outfitted with top-quality optics that are highly specialised. [Peter] was able to get his hands on a lens for a line-scan camera, and decided to put it to work on some macro photography instead.

Judging by the specs found online, this is a fairly serious piece of kit. It easily competes with top-shelf commercial optics, which is what piqued [Peter]’s interest in the part. Being such a specialised piece of hardware, you can’t just cruise over to eBay for an off-the-shelf adapter. Instead, a long chain of parts were used to affix this lens to a Sony AIII DSLR, converting from threaded fittings to a Nikon mount and then finally to Sony NEX mount.

Further work involved fitting an aperture into the chain to get the lens as close as possible to telecentric. This improves the lens’s performance for certain tasks, and makes focus stacking macro shots more readily achievable – something we’ve seen [Peter] tinker with before.

You never know what you might find when sorting through surplus industrial gear, could could score some high-performance hardware if you know where to look. It’s always great to see a cheap find become a useful instrument in the hacker toolbox!

Foam Board, Old Electronics, And Imagination Make Movie Magic

December 31, 2019 by Dan Maloney 11 Comments

When it comes to building sets and props for movies and TV, it’s so easy to get science fiction wrong – particularly with low-budget productions. It must be tempting for the set department to fall back on the “get a bunch of stuff and paint it silver” model, which can make for a tedious experience for the technically savvy in the audience.

But low-budget does not necessarily mean low production values if the right people are involved. Take [Joel Hartlaub]’s recent work building sets for a crowdfunded sci-fi film called Infinitus. It’s a post-apocalyptic story that needed an underground bunker with a Fallout vibe to it, and [Joel] jumped at the chance to hack the sets together. Using mainly vintage electronic gear and foam insulation boards CNC-routed into convincing panels, he built nicely detailed control consoles for the bunker. A voice communicator was built from an old tube-type table radio case with some seven-segment displays, and the chassis of an old LCD projector made a convincing portable computer terminal. The nicest hack was for the control panel of the airlock door. That used an old TDD, or telecommunications device for the deaf. With a keyboard and a VFD display, it fit right into the feel of the set. But [Joel] went the extra mile to make it a practical piece, by recording the modulated tones from the acoustic coupler and playing them back, to make it look as if a message was coming in. The airlock door looks great too.

Like many hacks, it’s pretty impressive what you can accomplish with a deep junk pile and a little imagination. But if you’ve got a bigger budget and you need some computer displays created, we know just the person for the job.

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A Soft Robotic Insect That Survives The Fly Swatter

December 31, 2019 by Sharon Lin 7 Comments

Swarms of robotic insects incapable of being swatted away may no longer be the product of science fiction and Black Mirror episodes. A team from EPFL’s School of Engineering has developed an insect propelled at 3 cm/s, dubbed the DEAnsect.

What makes this robot unique is its exceptional robustness. Two versions of the robot were initially developed, one tethered with ultra-thin wires capable of being squashed with a shoe without impacting its functions and the second fully wireless and autonomous. The robot weighs less than 1 gram and is equipped with a microcontroller and photodiodes to recognize black and white patterns.

The insect is named for its dielectric elastomer actuators (DEAs), an artificial muscle that propels it with vibrations and enables it to move lightly and quickly.

The DEAs are made of an elastomer membrane wedged between soft electrodes that are attracted to each other when a voltage is applied, compressing the membrane. The membrane returns to its original shape when the voltage is turned off. Movement is generated by switching the voltage on and off over 400 times per second. The team reduced the thickness of the membranes and developed soft, highly conductive electrodes only several molecules thick using nanofabrication techniques. They plan on fitting even more sensors and emitters to allow the insects to communicate directly with one another for greater swarm-like activity.

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Fail Of The Week: Ambitious Vector Network Analyzer Fails To Deliver

December 31, 2019 by Dan Maloney 18 Comments

If you’re going to fail, you might as well fail ambitiously. A complex project with a lot of subsystems has a greater chance of at least partial success, as well as providing valuable lessons in what not to do next time. At least that’s the lemonade [Josh Johnson] made from his lemon of a low-cost vector network analyzer.

For the uninitiated, a VNA is a versatile test instrument for RF work that allows you to measure both the amplitude and the phase of a signal, and it can be used for everything from antenna and filter design to characterizing transmission lines. [Josh] decided to port a lot of functionality for his low-cost VNA to a host computer and concentrate on the various RF stages of the design. Unfortunately, [Josh] found the performance of the completed VNA to be wanting, especially in the phase measurement department. He has a complete analysis of the failure modes in his thesis, but the short story is poor filtering of harmonics from the local oscillator, unexpected behavior by the AD8302 chip at the heart of his design, and calibration issues. Confounding these issues was the time constraint; [Josh] might well have gotten the issues sorted out had the clock not run out on the school year.

After reading through [Josh]’s description of his project, which was a final-year project and part of his thesis, we feel like his rating of the build as a failure is a bit harsh. Ambitious, perhaps, but with a spate of low-cost VNAs coming on the market, we can see where he got the inspiration. We understand [Josh]’s disappointment, but there were a lot of wins here, from the excellent build quality to the top-notch documentation.

Reverse Engineer PCBs With SprintLayout

December 31, 2019 by Al Williams 20 Comments

[Bwack] had some scanned pictures of an old Commodore card and wanted to recreate PC boards from it. It’s true that he could have just manually redrawn everything in a CAD package, but that’s tedious. Instead, he used SprintLayout 6.0 which allows you to import pictures and use them as a guide for recreating a PCB layout.

You can see the entire process including straightening the original scans. There are tools that make it very easy to place new structures over the original scanned images.

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