Mysterious Files PH

Let’s stop for a moment and pause to consider the smart bulb. Imagine going back 20 years and telling yourself that people will be putting computers capable of acting as web servers into light bulbs just so they can control them from their telephone instead of hitting the switch. The whole thing seems crazy — but its great, because it enables hacks like this one where [RickOOOOOO] takes a commercially-available ESP32 smart bulb, and hacks it into a local file server and digital library for banned books.

The word “banned” gets bandied about a lot — but assured, there’s nothing getting served up by [RickOOOOOO]’s bulb that’s going to help somebody will ill-intent build an improvised explosive device.  No, at least as conceived here, it appears to be full of easily-available e-books that were pulled from school libraries in the USA, which may-or-may not meet your personal definition of ‘banned’. Whatever you want to call them, we appreciate the idea that a student could hypothetically replace one of the bulbs at school with a hacked version serving up that sort of content. a bulb in such a school with a bulb hacked to host that sort of content–in minecraft, naturally.

In any case, the hardest part of the hack was carving the ESP32C3 in the bulb out of the IoToreo bulb enough to access it. Unfortunately having done so, [Rick] wasn’t able to get an SDcard interface soldered on, so he’s stuck with just 4MB for books and webserver. That means only a few epubs can fit on the bulb, but it’s better than those books being unavailable.

Like the solarpunk message board we featured recently, which also ran on an ESP32, the bulb broadcasts a public network that uses a captive portal to take you to the web interface of the library. From there, users can browse books– including learning from where they were banned and why–and admins can access a password-protected control panel. One neat work-in-progress feature on the control panel is that the bulb can still be used as a smart bulb, so you can try and match the light to its surroundings. In Minecraft, because of course we would never encourage kids to change light bulbs. Perish the thought!

Speaking of Minecraft, you can run a server on a lightbulb, too. Or DOOM, because of course even the light bulbs run DOOM now. What a time to be alive!

The basics of producing a stereophotograph of real life places were well-established by the time the View-Master arrived, but producing images of imaginary scenes was a bit more involved. [View Master Travels and Peter Dibble] took a look at how the fairy tale and media tie-in reels may have been made.

Staring with simple dioramas, View-Master eventually developed an entire team to work on fairy tales. One of the most influential members was sculptor [Florence Thomas]. She was instrumental in updating many of the original fairy tale reels from small scale miniatures to 1/6 scale dioramas for the scenes. Unfortunately, the department was eventually cut and all the original miniatures thrown away.

Before VCRs, View-Master was the primary way people could interact with their favorite TV shows and movies when they weren’t being broadcast. TV shows could be photographed while in production in Hollywood with a stereo camera giving great visual detail. Some cartoon and movie reels were less engaging, having been made from promotional images, giving more of a paper cutout appearance rather than “real” 3D. In either case, many of these visual techniques have been lost with little documentation on how they were achieved.

We previously covered [View Master Travels and Peter Dibble]’s History of the View-Master and how you can digitize the disks for posterity.

Slow-scan CRTs were never exactly common compared to their faster cousins, but given the popularity of Slow Scan TV (SSTV) amongst hams and NASA broadcasts, many of you are probably familiar with them. The slow scan rate of SSTV meant it required much less bandwidth, but in the early days you needed a CRT with a long-persistence phosphor to hold onto the image. [AJRussell]’s Glow Engine works much the same, with one key difference — instead of cathode rays, he’s using a frikkin laser beam.

In this case, the phosphor is Strontium Aluminate, the same stuff that gives most glow-in-the-dark toys and filament its kick. Energized by a 405 nm laser of questionable wattage, the phosphor will glow for several seconds, allowing the creation of an image. So while this is a laser projector, it works more like a CRT than most galvo projectors, which rely on Persistence of Vision to create an image. Here it’s persistence of fluorescence.

Because the phosphor is so slow, you don’t need the rapid scan rate you would with a laser projector, so [AJRussel] can skip the mirror drum and just mount the mirror on a gimbal motor. Field Oriented Control makes the precise sweeping of the gimbal possible, via a hall-effect sensor and the SimpleFOC library that we featured last year. The other axis just moves the laser and gimbal assembly on a big stepper. The whole thing is driven via an ESP32. The biggest downside is that the short focus range of the repurposed engraving laser means it’s smack dab in front of the screen.

This is a work in progress and still changing, so it’s not clear which — if any — of the various SSTV modes the Glow Engine can handle. Given the number of scanlines in the photos it looks like a good use case, and without trying it the timing might work, too:  [AJ] reports scanning left-to-right to generate a frame takes about eight seconds, depending on the resolution, and depending on the PWM power setting on the laser the image can last up to a minute.

Given the one-minute decay time with this particular phosphor, perhaps he can make a clock. If you have a longer-lasting glow powder, we’ve seen  uses for such a persistent display as well.

As simple as the concept of adding two numbers appears at first glance, doing it in the 1970s in Intel’s 8087 FPU with its 69-bit adder was still a tall order. This is namely the core feature that many features like tangents, cosines and exponentiation rely on, so it had to be basically perfect. In a recent die-level analysis of the 8087 [Ken Shirrif] dives into the structure, layout and functioning of this ‘beating heart’ of this piece of semiconductor history.

Although anyone can build a simple binary adder out of off-the-shelf parts including 74-series logic ICs, the problem is to make it fast so that the 69th bit doesn’t have to wait for e.g. a carry to trickle all the way through the preceding bits. The main way that this is solved is by breaking addition into 4-bit blocks, reducing the problem by a factor of four, along with an optimized Manchester carry-chain carry-lookahead implementation.

The main advantage of this variation of a carry-lookahead is that it reduces the number of required transistors, without sacrificing too much performance. Later on Intel would switch to the faster, but more transistor-intensive Kogge-Stone adder.

Implementing this entire adder with NMOS technology and wiring it all up to the rest of the die required a lot of ingenuity on the side of the Intel engineers, as as previously noted this adder is effectively always used in any operation at some stage. This necessitates many surrounding registers and in turn circuitry to manage these, with part of the complexity handled in microcode and part in silicon.

One of the joys you get to experience whether as a proud parent or pet owner is that a lot of things get left around haphazardly. You could of course pick every piece of discarded clothing, half-destroyed toy and detritus yourself, but as a parent of three children himself [Nathaniel Nifong] opted to use his engineering background to potentially over engineer a wires-suspended robotic claw to do this picking up for him.

What he calls Stringman robots requires an anchoring point at four corners of a room, after which the robotic crane can then scour across the ceiling, identify targets to pick up and move these to predesignated drop-off points. It’s an open source project with the LeRobot-based firmware available on GitHub in addition to build instructions for the physical hardware. There’s also a pilot run of ready to use hardware and kits for those who want to trial it, but aren’t interested in building it themselves via [Nathaniel]’s company website.

The basic idea is that this crane can run for an hour or so and deal with the mess in its room without having to do anything yourself. The process isn’t perfect yet, of course, with the underlying diffusion transformer to implement machine vision requiring more refinement. The gripper itself struggles with objects like books, which can be a concern for parents and bookworms, and of course while the crane is operating the wires will dip down as a potential risk to anyone in the room.

Compared to an overhead crane like a traditional bridge crane this wire-suspension crane is probably more stable, but either is an interesting engineering challenge when applied to a household. Next it would probably also be cool if items could be put away where they belong instead of dropped into a bin, as so far that task will still be left to deal with by the adult humans.

Want to make your own ergonomic mouse but don’t know where to start? Why not try [psudoku]’s Kotinos design?

It’s a scaffold-like fingertip shell that uses the internals of an HSK Pro mouse. Each fingertip gets its own little saddle-shaped nook, and things like hand size and paddle surface can all be configured by modifying the OpenSCAD scripts.

[psudoku]’s unit looks to us as though it was maybe made using multi-jet fusion (MJF) 3D printing, but it should be perfectly printable on hobbyist printers, whether resin- or filament-based.

Comfort of the contact surfaces is left up to the end user, but if your print lacks smoothness and sanding isn’t your jam, you might consider a layer of fabric tape to create a velvet-like surface on a 3D print. That’s a trick we’ve kept in mind ever since seeing it put to good use, cushioning the hardware in a DIY steam deck case.

Is the minimalist scaffold approach to a mouse not your style, or does your hand crave something less lightweight but a little more personalized? You might want to craft a truly custom-fitted mouse, for which clay is the way.

You have to be a pretty big aviation nerd to know about [Willard Ray Custer] and his channel wing concept, but if you are, you’ll be giddy to hear about the semicircular profile of the HopFlyt Cyclone drone’s tandem wings. If you’re not quite that much of a nerd, please keep reading, because it’s a really neat concept that never — er — quite got off the ground.

[Custer]’s idea was pretty simple, and born of a shift in reference frame — he realized that only the relative wind over the wing mattered, not the airspeed of the entire aircraft. The same idea drives every blown-wing short-takeoff-and-landing (STOL) project from the DHC-7 turboprop airliner to the An-72 cargo jet: air from the engines washes over the wings, creating lift. Where [Custer] went further is that rather than blowing air over a straight wing, he wrapped the wing under the propeller in a semicircle to maximize the area of lower pressure — and thus lift — creating the “channel wing” that bears his name.

Theoretically, an aircraft with channel wings and powerful enough engines might be able to do vertical takeoffs just from the blown lift, but none of [Custer]’s prototypes demonstrated that — just excellent short-field capability. The HopFlyt drone would be the same, except that, being a tandem, it has double the channel wings of [Custer]’s more-conventional designs, and it’s also a tilt-wing to boot. In that mode, the added low-speed lift from the channel wing makes transitions easier than they otherwise would be — which isn’t anything to sneeze at, since transitioning from vertical to horizontal flight has always been the real bane of VTOL projects.

They’re claiming a reduced fuel burn of 10% in hover and transition thanks to the extra lift from the channel wings. You can see their prototype in action in the demo video embedded below. We once featured a project that went even further, blowing air across a special hollow wing for propulsion and blown lift. The easiest eVTOL project still starts with a quadcopter, though.