We love electromagnetic displays: take the modern look of a digital readout, combine with the low-tech coil mechanism that you theoretically could create yourself, add a dash of random clacking sounds, and what’s not to like? Evidently, [Nicolas Kruse] shares our affection for these displays, because he’s taken it beyond theory and created a 7-segment magnetically-actuated display from scratch.
The display is 3D-printed, as you would expect these days. Each segment contains a small neodymium magnet, and each coil a 1 mm iron core for flux concentration. The coils are driven with a 1.6 A peak current, causing the segments to flip in less than 10 ms. [Nicolas] provides STL files for the display base, segments, and spools so you can print your own display. He’s also released the schematics and code for the driver, which uses an ATtiny44 to drive the coils through N- and P-channel MOSFETs. Initially designed to drive a passive 4×7 matrix of displays, the driver couldn’t quite manage to flip one segment without affecting its neighbors. However, for a single display, the driver works fine. We hope he figures out the matrix issue soon, because we really want to see a clock made with these displays.
You can see (and hear) a short video of the display in action after the break. The clacking does not disappoint!
Continue reading “Electromagnetic 7-Segment Display Easy on the Eyes AND the Ears”
LED matrix displays and flat-screen monitors have largely supplanted old-school electromechanical models for public signage. We think that’s a shame, but it’s also a boon for the tinkerer, as old displays can be had for a song these days in the online markets.
Such was the case for [John Whittington] and his flip-dot display salvaged from an old bus. He wanted to put the old sign back to work, but without a decent driver, he did what one does in these situations — he tore it down and reverse engineered the thing. Like most such displays, his Hannover Display 7 x 56-pixel flip-dot sign is electromechanically interesting; each pixel is a card straddling the poles of a small electromagnet. Pulse the magnet and the card flips over, changing the pixel from black to fluorescent green. [John] used an existing driver for the sign and a logic analyzer to determine the protocol used by the internal electronics to drive the pixels, and came up with a much-improved method of sending characters and graphics. With a Raspberry Pi and power supply now resident inside the case, a web-based GUI lets him display messages easily. The video below has lots of details, and the code is freely available.
You may recall [John] from a recent edge-lit Nixie-like display. Looks like he’s got a thing for eye-catching displays, and we’re fine with that.
Continue reading “Flip-Dot Display Brought Out of Retirement by New Drivers”
Flip-Dot displays are so awesome that they’re making a comeback. But awesome is nothing when you can have an insane flip-dot display that is three-dimensional with the dots floating in mid-air. Researchers at the Universities of Sussex and Bristol have built what they call JOLED, an array of floating pixels that can be controlled via a combination of ultrasonic standing waves and an electrostatic field. These “voxels” can be individually moved in space via ultrasonics, and can also be individually flipped or rotated through any angle, via the electrostatic field.
The key to the whole thing is something they call Janus Objects – hence JOLED. Janus particles have different features or chemistry on two opposite sides. A portion of each voxel is speckled with a small amount of titanium dioxide nano powder. This gives it a bipolar charge that makes it respond to the variable electrostatic field and hence capable of axial rotation. Half of each white voxel can then be covered with a contrasting color – red, blue, black – to achieve the flip dot effect. Each voxel appears to be a couple of millimeters in diameter. The ultrasonic actuators appear to be regular piezo transmitters found in every hacker’s parts bin. Transparent glass plates on opposite sides apply the variable electrostatic field.
While this is still experimental and confined to the research lab, future applications would be interesting. It would be like breaking e-ink displays out of their flat glass confines and giving them a third dimension. The short, two-minute video after the break does a good job of explaining what’s going on, so check it out. Now, who want’s to be the first to build a JOLED clock?
Thanks to [Garrow] for tipping us off about this.
Continue reading “JOLED – a 3D Flip Dot Display”
Admit it, you’ve always wanted to have your own flip-dot display to play with. Along with split-flap displays, flip-dots have an addictive look and sound that hearkens back half a century but still feels like modern technology. They use a magnetic coil to actuate each pixel — physical discs painted contrasting colors on either side. It means that you really only need electricity when changing the pixel, and that each pixel makes a satisfyingly unobtrusive click when flipped. The only problem with the displays is that they’re notoriously difficult to get your hands on.
Breakfast, a Brooklyn-based hardware firm known for creative marketing installations, unveiled their Flip-Disc Display System this morning. Used displays have come up on the usual sites from time to time, but often without a controller. Traditional flip-dot manufacturers haven’t sought out the individual hacker or hackerspace, and a click-to-buy option has been difficult if not impossible to find.
Breakfast’s offering modernizes the driver used to manage all of those electro-mechanical pixels. Whether this will make the displays more accessible is a question that still needs to be answered.
Continue reading “Flip Dot Displays Appear with Modernized Drivers”
Flip-dot displays are grand, especially this one which boasts 74,088 pixels! I once heard the hardware compared to e-ink. That’s actually a pretty good description since both use a pixel that is white on one side and black on the other, depend on a coil to change state, and only use electricity when flipping those bits.
What’s remarkable about this is the size of the installation. It occupied a huge curving wall on the ooVoo booth at 2015 CES. We wanted to hear more about the hardware so we reached out to them they didn’t disappoint. The ooVoo crew made time for a conference call which included [Pat Murray] who coordinated the build effort. That’s right, they built this thing — we had assumed it was a rental. [Matt Farrell] recounts that during conception, the team had asked themselves how an HD video chat for mobile company can show off display technology when juxtaposed with cutting edge 4k and 8k displays? We think the flip-dot was a perfect tack — I know I spent more time looking at this than at televisions.
Join us after the break for the skinny on how it was built, including pictures of the back side of the installation and video clips that you have to hear to believe.
Continue reading “The Giant Flip-Dot Display at CES”
What is it that we like so much about inefficient, noisy clocks made with inappropriate technology? Answer the question for yourself by watching the video (below) that [David Henshaw] sent us of Dottie, the flip-dot clock.
But besides the piece itself, we really like the progression in the build log, from “how am I going to do this?” to a boxed-up, finished project.
Another stunning aspect of this build is just how nice an acrylic case and a raft of cleverly written software can make a project look. You’d never guess from the front that the back-side was an (incredible) rat’s nest of breadboards and Ethernet wires. Those random switching patterns make you forget all the wiring.
And the servo-steered, solenoid-driven chimes are simply sweet. We’re sure that we’d love to hear them in real life.
Continue reading “Dottie the Flip Dot Clock”
While casually lurking on a famous auction website, [TeddyDesTodes] found the gem shown in the above picture and reverse engineered it. This is a flip dot display, the Brose Vollmatrix compact to be precise. It consists of a grid of small metal discs that are black on one side and yellow on the other, set into a black background. With power applied, the disc flips to show the other side. The disc is attached to an axle which also carries a small permanent magnet. Positioned close to the magnet is a solenoid. By pulsing the solenoid coil with the appropriate electrical polarity, the magnet will align itself with the magnetic field, also turning the disc.
After carrying the 25kg display from his post office to home, [TeddyDesTodes] opened it and discovered that the main control board was using two RS422 transceivers. So he fired up his bus pirate, started to sniff the traffic and noticed that several commands were repeatedly sent. [TeddyDesTodes] stopped the transmission, sent these particular commands and had the good surprise to see some dots flipped. From there, displaying something was a piece of cake.
If this is familiar to you it may be because it was shared in one of the Trinket Contest Updates. But the background details were just so much fun we think this deserves a full feature of it’s own. Do you agree?