Manual Larson Scanner Invites You To Crank It

August 22, 2020 by Lewin Day 12 Comments

Hasselhoff make Larson Scanners famous. That’s the name for the scanning red lights on the front of KITT, the hero car from the popular 1980s TV series Knight Rider. Despite serving a solely aesthetic role, they remain a fun and popular LED project to this day. Putting a new twist on the old concept, [Pete Prodoehl] whipped up a Larson Scanner that you crank to operate.

Built out of LEGO, the project relies on a hand crank to work. The crank turns a drum, onto which is placed several strips of conductive Maker Tape – a steel/nylon material which we’ve looked at before. Strips of tape running side-by-side are bridge by segments of tape on the drum as it turns. The LEDs are switched on in the requisite pattern of a traditional Larson scanner.

The project has inspired further possibilities, such as using similar techniques to produce an electronic music box or player piano that will change tempo as the user changes the speed with the crank. [Pete] notes that turning the crank is an inherently enjoyable experience, and given the wonder inherent in hand-cranked musical projects like Marble Machine X, we can’t wait to see where this one goes next. Video after the break.

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Palm-Sized Sixteen Segments Light The Way To Our Hearts

August 20, 2020 by Kerry Scharfglass 20 Comments

It’s no secret that we here at the Hackaday are suckers for cool display. LEDs, OLEDs, incandescent, nixie or neon, you name it and we want to see it flash. So it fills us with joy to discover a new way to build large, daisy-chainable 16-segment digits, and even more excited to learn how easy they are to fab and assemble.

A cousin of the familiar 7 segment display, the 16 segment gives so many more possibilities (128% more possibilities to be exact) for digit display. To be specific, those extra segments unlock the ability to display upper and lowercase latin characters as well as scads of punctuation.

But where the character set is complex, the assembly is anything but thanks to a great design from [Kolibri] called klais-16. They’re available fully assembled if you want to jump straight to code, but thanks to thorough documentation (seriously, check this out) assembly is a snap.

Each module is composed a very boring PCBA base layer which should be inexpensive from the usual sources, even when ordering one fully assembled. A stackup of three more PCBs are used for spacing and diffusion with plans for die-cut or injection mold layers if a larger production run ends up happening. Board dimensions for each character are 100 mm x 66.66 mm (about 4″ x 2.5″). Put together, each module can stand on its own or be easily daisy-chained together to make a longer single display.

Addressing all those bits with an elaborate, ugly control scheme would be a drag but fortunately the firmware for the onboard STM8 microcontroller exposes a nice boring serial interface which can be used without configuration to display strings. There’s even an example Windows Batch script!

Abused Hard Drive Becomes POV Clock

August 14, 2020 by Dan Maloney 8 Comments

We all know that there’s not much to do with an old hard drive. Once you render the platters unreadable and perhaps harvest those powerful magnets, there’s not much left of interest. Unless, of course, you turn the whole thing into a persistence-of-vision clock.

At least that’s what [Leo] did when he created “PendoLux”. The clock itself is pretty simple; like any POV project, it just requires a way to move an array of flashing LEDs back and forth rapidly enough that they can trick the eye into seeing a solid image. [Leo] put the read head mechanism of an old HDD into use for that, after stripping the platters and motor out of it first.

The voice coil and magnet of the head arm are left intact, while a 3D-printed arm carrying seven RGB LEDs replaces the old heads. [Leo] added a small spring to return the arm to a neutral position, and used an Arduino to drive the coil and flash the LEDs. Getting the timing just right was a matter of trial and error; he also needed to eschew the standard LED libraries because of his heavy use of interrupts and used direct addressing instead.

POV clocks may have dropped out of style lately — this hard drive POV clock and a CD-ROM version were posted years ago. But [Leo]’s clock is pretty good looking even for a work in progress, so maybe the style will be making a comeback.

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Springs And Things Wrap Into A Polyhedron Of Interactive LED Art

August 2, 2020 by Dan Maloney 6 Comments

Any resemblance between The Wobble Sphere and a certain virus making the rounds these days is purely coincidental. Although as yet another project undertaken during the COVID-19 lockdowns, we can see where the inspiration came from.

Wobble Sphere is another work of interactive art from the apparently spring-driven imagination of [Robin Baumgarten], whose Quantum Garden piece graced our pages last year. The earlier, flatter version used a collection of spring door stops — the kind that sound awesome when plucked by a passing foot — each of which is surrounded by a Neopixel ring. The springs act as touch sensors that change the patterns and colors on the LED rings in endlessly fascinating ways.

For Wobble Sphere, [Robin] took the same spring and LED units, broke them into a collection of hexagonal and pentagonal PCBs, and wrapped the whole thing up into a 72-sided polyhedron. There’s some impressive mechanical and electrical engineering involved in the transition from 2D to 3D space, not least of which is solving the problem of how to connect everything while providing pluck-friendly structural support. The former was accomplished with a ton of ribbon cables, while the latter was taken care of with a combination of a 3D-printed skeleton and solder connections between adjacent PCBs. The result is a display that invites touch and rewards it with beautiful patterns of light chasing around the sphere. See it in action in the video after the break.

Lest anyone think springs are the only tool in [Robin]’s box, we mustn’t forget that he once set a knife-wielding Arduino-powered game on an unsuspecting public. Check it out; it’s way more fun than it sounds.

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Playing The Pixelflut

August 1, 2020 by Kerry Scharfglass 7 Comments

Every hacker gathering needs as many pixels as its hackers can get their hands on. Get a group together and you’ll be blinded by the amount of light on display. (We propose “a blinkenlights” as the taxonomic name for such a group.) At a large gathering, what better way to show of your elite hacking ability than a “competition” over who can paint an LED canvas the best? Enter Pixelflut, the multiplayer drawing canvas.

Pixelflut has been around since at least 2012, but it came to this author’s attention after editor [Jenny List] noted it in her review of SHA 2017. What was that beguiling display behind the central bar? It turns out it was a display driven by a server running Pixelflut. A Pixelflut server exposes a display which can be drawn on by sending commands over the network in an extremely simple protocol. There are just four ASCII commands supported by every server — essentially get pixel, set pixel, screen size, and help — so implementing either a client or server is a snap, and that’s sort of the point.

While the original implementations appear to be written by [defnull] at the link at the top, in some sense Pixelflut is more of a common protocol than an implementation. In a sense, one “plays” one of a variety of Pixelflut minigames. When there is a display in a shared space the game is who can control the most area by drawing the fastest, either by being clever or by consuming as much bandwidth as possible.

Then there is the game of who can write the fastest more battle-hardened server possible in order to handle all that traffic without collapsing. To give a sense of scale, one installation at 36c3 reported that a truly gargantuan 0.5 petabytes of data were spent at a peak of rate of more than 30 gigabits/second, just painting pixels! That’s bound to bog down all but the most lithe server implementation. (“Flut” is “flood” in German.)

While hacker camps may be on pause for the foreseeable future, writing a performant Pixelflut client or server seems like an excellent way to sharpen one’s skills while we wait for their return. For a video example check out the embed after the break. Have a favorite implementation? Tell us about it in the comments!

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Tiny Circuit Sculpture Keeps The Night Watch

July 27, 2020 by Kristina Panos 8 Comments

If you’re planning to get into circuit sculpture one of these days, it would probably be best to start with something small and simple, instead of trying to make a crazy light-up spaceship or something with a lot of curves on the first go. A small form factor doesn’t necessarily mean it can’t also be useful. Why not start by making a small automatic night light?

The circuit itself is quite simple, especially because it uses an Arduino. You could accomplish the same thing with a 555, but that’s going to complicate the circuit sculpture part of things a bit. As long as the ambient light level coming in from the light-dependent resistor is low enough, then the two LEDs will be lit.

We love the frosted acrylic panels that [akshar1101] connected together with what looks like right angle header pins. If you wanted to expose the electronics, localize the light diffusion with a little acrylic cover that slips over the LEDs. Check it out in the demo after the break.

There’s more than one way to build a glowing cuboid night light. The Rubik’s way, for instance.

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500 Lasers Are Not Necessarily Better Than One, But They Look Great

July 13, 2020 by Dan Maloney 29 Comments

If playing with but a single laser pointer is fun, then playing with 500 laser pointers must be 500 times the fun, right? So by extension, training 500 laser pointers on a single point must be the pinnacle of pointless mirth. And indeed it is.

When we first spotted this project, we thought for sure it was yet another case of lockdown-induced boredom producing an over-the-top build. Mind you, we have no problem with that, but in this case, [nanoslavic] relates that this is actually a project from a few years back. It’s really as simple as it looks: 500 laser pointer modules arranged on a plate with a grid of holes in a 25 by 20 array. As he placed the laser modules on the board with a glob of hot glue, he carefully aimed each one to hit a single point about a meter and a half away. There are also a handful of blue LEDs nestled into the array, because what project is complete without blue LEDs?

The modules are wired in concentric circuits and controlled by a simple bank of toggle switches. Alas, 500 converging ~~150-mW~~ 5 mW lasers do not a ~~75-W~~ 2.5 W laser make; when fully powered, the effect at the focal point is reported to be only a bit warm. But it looks incredible, especially through smoke. Throwing mirrors and lenses into the beam results in some interesting patterns, too.

You’ll still need to take safety seriously if you build something like this, of course, but this one is really just for show. If you’re really serious about doing some damage with lasers, check out the long list of inadvisable laser builds that [Styropyro] has accumulated — from a high-powered “lightsaber” to a 200-Watt laser bazooka.

(Terminate your beams carefully, folks. We don’t want anyone going blind.)

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