Don’t Look Up, Or You’ll See The Time From This VFD Projection Clock

Ceiling clocks were a bit of a thing back in the days when clock radios were a fixture of nightstands. The idea was to project the time onto the ceiling so you’d only have to roll over onto your back and open your eyes to check the time, instead of potentially disturbing your slumber by craning your neck around to see the front of the clock.

As we recall, what sounded like a good idea was iffy in practice, with low-end optics and either weak incandescent bulbs or blazing LEDs. This nifty VFD projection clock by [Thomas Shupfs] seeks to fix those problems, and from the look of it does a pretty good job. It takes advantage of something else that fell out of favor with consumers — analog photography — by tapping into the ready supply of unwanted lenses. He paired that up with an IVL2-7/5 vacuum fluorescent display inside a 3D printed case with a cone-shaped extension to hold the lens at the right distance above the display. [Thomas] says that the STM32 software only supports JSON-RPC over USB at this time, and includes a couple of Python programs with examples of how to set the time and check the accuracy of the clock.

[Thomas] compares the clock head-to-head against his old LED projection clock, as seen in the featured image above; we flipped it for a better idea of what it would look like from bed. We’ve got to say the soft blue glow of the VFD would be a lot more pleasant to wake up to than the bright red LED projection. But this soft white projection clock is nice too.

Thanks to [skymab] for the tip.

Behold A DIY VR Headset Its Creator Will “Never” Build Again

Unsatisfied with commercial VR headset options, [dragonskyrunner] did what any enterprising hacker would: gathered parts over time and ultimately made their own. Behold the Hades Widebody (HWD), a DIY PC VR headset that aims for a wide field of view and even manages to integrate some face and eye tracking.

The Fresnel elements hugging the primary lenses provide a way of extending the display into the wearer’s peripheral vision.

[dragonskyrunner] is — and we quote — “NEVER building one of these again.” The reason is easily relatable to anyone who has spent a lot of time and effort creating something special: it does the job it was created for, but it also has limitations and is a lot of work. If one were to do it all over again, there would be a host of improvements and changes to consider. But one won’t be doing it all over again any time soon because it’s done now.

The good news is that [dragonskyrunner] made an effort to document things, so there is at least a parts list and enough details for any suitably motivated hacker to replicate the work and perhaps even put their own spin on it.

The Hades Widebody has a dual-lens arrangement and wide displays that aim to provide a wider field of view than most setups allow. There’s a main lens in front of the user’s eyes and a cut Fresnel lens providing a sort of extension to the side. [dragonskyrunner] claims that while there is certainly not a seamless transition between the lens elements, it does a better job than an Ambilight at providing a sense of visuals extending into the wearer’s peripheral vision.

The DIY spirit of making a piece of hardware to suit one’s own needs is exactly the sort of thing that would fit into our 2023 Cyberdeck content, and while a headset by itself isn’t quite enough to qualify (devices must have some form of usable input and output), it just might get those creative juices flowing.

Inexpensive Reading Glasses Become Stereoscope

It’s an unfortunate consequence of growing older, that no longer are you able to read the print on a SOT-23 package or solder a QFN without magnification. Your eyes inexorably start to fail, and to have any hope of continuing a set of reading glasses is required. We have this in common with [Niklas Roy], who noticed while shopping for cheap reading glasses that their lenses were of surprisingly good quality. The result of this observation was a stereoscope made from card and a few euros worth of eyewear.

In the tradition of [Niklas]’ work it has a high level of attention to detail, which manifests itself here in a parametric web-based template generator to produce a result tailored to your glasses. It’s a fairly straightforward trapezoid shape, with a compound lens made from two sets of glasses drilled and held back-to-back with zip ties.

It served as a project for a group of children, and of course because stereo cameras are a relative rarity he also investigated taking his own pictures by moving a smartphone for left and right eye perspectives. It seems the youngsters had a lot of fun.

These lenses hadn’t come up on our radar until now, but like many goodies in a dollar store they’re certainly something to take a look at. Maybe not as a stereoscope for everyone though, some of us can’t see what the fuss is about.

Lenses: From Fire Starters To Smart Phones And VR

In antiquity, we see examples of magnifying crystals formed into a biconvex shape as early as the 7th century BC. Whether the people of that period used them either for fire-starting purposes or vision is unclear. Still, it is famously said that Emperor Nero of Rome watched gladiator games through an emerald.

Needless to say, the views we get through modern lenses are a lot more realistic. So how did we get from simple magnifying systems to the complex lens systems we see today? We start with a quick journey through the history of the camera and the lens, and we’ll end up with the cutting edge in lens design for smartphone cameras and VR headsets.

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Molding complex lenses

Molding Complex Optics In A Completely Fluid System

Traditional lensmaking is a grind — literally. One starts with a piece of glass, rubs it against an abrasive surface to wear away the excess bits, and eventually gets it to just the right shape and size for the job. Whether done by machine or by hand, it’s a time-consuming process, and it sure seems like there’s got to be a better way.

Thanks to [Moran Bercovici] at Technion: Israel Institute of Technology, there is. He leads a team that uses fluids to create complex optics quickly and cheaply, and the process looks remarkably simple. It’s something akin to the injection-molded lenses that are common in mass-produced optical equipment, but with a twist — there’s no mold per se. Instead, a UV-curable resin is injected into a 3D printed constraining ring that’s sitting inside a tank of fluid. The resin takes a shape determined by the geometry of the constraining ring and gravitational forces, hydrostatic forces, and surface tension forces acting on the resin. Once the resin archives the right shape, a blast of UV light cures it. Presto, instant lenses!

The interface between the resin and the restraining fluid makes for incredibly smooth lenses; they quote surface roughness in the range of one nanometer. The use of the fluid bed to constrain the lens also means that this method can be scaled up to lenses 200-mm in diameter or more. The paper is not entirely clear on what fluids are being used, but when we pinged our friend [Zachary Tong] about this, he said he’s heard that the resin is an optical-grade UV adhesive, while the restraining fluid is a mix of glycerol and water.

We’re keen to see [Zach] give this a try — after all, he did something similar lately, albeit on a much smaller scale.

Continue reading “Molding Complex Optics In A Completely Fluid System”

From An Eye To An Eye: Human Muscles As A Joystick

The interface between humans and machines has been a constantly evolving field. Sure the computer mouse was a game-changer, but time moves on. We are now looking at integrating machines via soft HMIs for personal applications. A research team led by the University of California, San Diego has presented a paper interfacing a soft lens with the human eye.

The lens itself is a pair of electroactive elastomer films that encapsulates a small quantity of saltwater. These films constitute the muscle and are controlled by an external source of electrical pulses. The signals are generated when electrodes placed around the eye of a subject and detect movement. Actions such as blinking are converted to a zoom-in-zoom-out activity which is designed to mimic human squinting.

The suggested potential applications are visual prostheses, adjustable glasses, VR, and even soft robots eyes. Yes, we are heading from whirring robots to squishy robots, but that also means that people with disabilities can get a second chance. This approach is non-invasive as opposed to brain implants.

[via Phys.org]

[Thanks for the tip Qes]

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Lenses For DIY Augmented Reality Will Get A Bit Less Unobtainable

You may remember that earlier this year Leap Motion revealed Project North Star, a kind of open-source reference design for an Augmented Reality (AR) headset. While it’s not destined to make high scores in the fashion department, it aims to be hacker-friendly and boasts a large field of view. There’s also an attractive element of “what you see is what you get” when it comes to the displays and optical design, which is a good thing for hackability. Instead of everything residing in a black box, the system uses two forward-facing displays (one for each eye) whose images are bounced off curved reflective lenses. These are essentially semitransparent mirrors which focus the images properly while also allowing the wearer to see both the displays and the outside world at the same time. This co-existence of both virtual and real-world visuals are a hallmark of Augmented Reality.

A serious setback to the aspiring AR hacker has been the fact that while the design is open, the lenses absolutely are not off the shelf components. [Smart Prototyping] aims to change that, and recently announced in a blog post that they will be offering Project North Star-compatible reflective lenses. They’re in the final stages of approving manufacture, and listed pre-orders for the lenses in their store along with downloadable 3D models for frames.

When Leap Motion first announced their open-source AR headset, we examined the intruiguing specifications and the design has since been published to GitHub.  At the time, we did note that the only option for the special lenses seemed to be to CNC them and then spring for a custom reflective coating.

If the lenses become affordable and mass-produced, that would make the design much more accessible. In addition, anyone wanting to do their own experiments with near-eye displays or HUDs would be able to use the frame and lenses as a basis for their own work, and that’s wonderful.