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.
Shockingly Short Development Time
![[Pat Murray] toils away... that's a lot of wiring!](https://i0.wp.com/hackaday.com/wp-content/uploads/2015/01/img_2682.jpg?w=300&h=225&ssl=1 "IMG_2682")
Get this, conception to finished construction for the wall was just under two months. The first pitch for funding happened the last week of October and the rig was finished about a week before Christmas.
In the video below you can just make out the panels which make up the display. Each of them hosts a 28 by 14 grid of flip-dots. The panels are arranged in 21 columns of 9. This provides a black and white display resolution of 588×126. Cognitively, that’s horrible resolution. But the sheer size and novelty of the technology makes the 74,088 mechanical pixels look and sound stunning as they click their way from one state to the next.
Each module has a built-in controller which are commanded via serial. To gang 189 of them into a single display, [Pat] sourced some serial to Ethernet hardware from Grid Connect. These adapters report back to a single computer via 64 Ethernet cables. That box plays back a video file, adapting it on the fly using Adobe Air to send packets to the IP addresses of the Ethernet controllers.
All of this is supplied by a trio of 56A, 24V power supplies. At a refresh rate of 30fps, when flipping all the dots at once this is a max current draw of 189 panels * 0.680 Amps = 128.52A @ 24VDC (Same power as 28 Amps @ 110VAC = 3085W).
Making it Interactive
The display wasn’t just rolling video. Interspersed with ooVoo’s advertising these cartoon faces would emerge. Space evenly along the length of the display are PrimeSense depth cameras. [Pat] told us that these were chosen over the Kinect sensors because they are more suited for up-close facial recognition. In conjunction with Affectiva and Faceshift, your facial disposition is measured and translated to the cartoon character. Each sensor has its own Mac mini which parses the data and sends commands over the network to the box controlling the display.
Our European readers may get a chance to see this one in person. ooVoo will be taking the display to the Mobile World Congress in Barcelona, March second through the fifth.
eInk doesn’t use a coil (or magnetism). It pulls black dots through a white liquid using a charge differential. When the dots are pulled to the back it looks white, when pulled to the front it looks black.
Huh, I thought they were micro-balls, white on one side and black on the other which swivel due to magnetism. I know I’ve read about that before. Is it a different type of technology?
You’ll find some data here http://www.flipdots.com/
I thought they were magnetic too, but more like a Magnadoodle.
IIRC the magnetic ball technology failed on two fronts; they couldn’t get the magnetic domains small enough to get a decent resolution, and the balls didn’t always rotate properly so you’d get ‘noise’ in the display.
There is more than one type of flip-dot display.
This type of eInk technology did exist in research, but for the reasons matt said, it was never really used.
I think the point they were making is that it has two states and doesn’t require power to maintain state.
This guy gets it.
woaaah.
But how does it work? Did they use off-the-shelf flip dots or assemble something from scracth? Do the dots rotate by magnetism or does a solenoid push/pull on a lever? drawing? detail pictures? please. I love flip-dots.
BTW Alan is right. e-ink uses electrical charge to move particles, but the effect is the same as flip-dots.
I see they are using 28×14 pixel panels, and flipdots.com sells 28×14 panels, so I’m going to guess they bought 189 of them. http://www.flipdots.com/flip-dot-boards-xy5-14×28.html#.VLbJgCvStpU
Which means its close to $100K all the panels.
That VC money needs to get spent somehow. Party like it’s 1999..
On the upside, it seems to have drawn the crowds and we got to see a cool build. :)
Trade show booths are shockingly expensive–it’s easy to spend tens of thousands of dollars on something completely bland and static that won’t get viral coverage outside the show. This at least got me to glance briefly at ooVoo which I wouldn’t have done otherwise.
When you buy that much of something, you generally negotiate the price rather than pay full retail.
For a video wall, that’s par for the course.
I love the sound it makes :).
Me too! I expect the sound is why they did so much of that random snow. Pretty cool!
The dots aren’t perfect; sometimes they get stuck. So, “random snow” was our way to reset the display… but I’m glad you guys like the sound!
I really liked the snow effect. It was an in-focus out-of-focus transition. On Flip Dots.
That was the very last animation we built! Designed out of necessity. It’s awesome that it turned out to be one of the most well-loved parts of the installation.
As someone who has seen WAY too many lame booths, you’ve hacked yourself a good one, here. Well done, wish I’d been able to see it in person. And much respect to the folks who actually designed and built it. You’ve done WAY better than hiring a bunch of booth babes (an institution I wish would disappear).
Yea, when it’s really going I don’t if it sounds more like a flock of birds taking off or a rattlesnake but it is cool!
nnnnnnnnnn
!
Awww… it’s like displays from “The Difference Engine” came to live…. wow!
If you haven’t seen the real Difference Engine at the Computer History Museum, it’s worth the trip. They actually run it. It’s beautiful to watch.
May be it is worth the trip. But the trip would be 16+ hours and a USA visa. Which is a bit difficult due to current political situation.
B & W with dead lots of pixels. So 90th.
It’s shocking to see how many dead pixels there are. After decades of development, these things apparently still don’t work.
The tech is pretty much unchanged from what it was 50+ years ago. We actually had to replace a lot of panels and fix a lot of diodes and poor soldering connections. Given more time we would have fixed the dozen or so dead pixels.
…ninetieth what?
He meanth the nineteen ninetieth, thupid.
The dead pixels are one of the first things I saw! Man I hate how that is! Guess it comes from being an engineer and
being obsessed by details all the time… Still really cool to watch and listen to though!
Since the video starts with a full screen of random noise dead pixels can’t have been the first thing you saw.
got you :)
I kind of like the occasional dead pixel – we’re so accustomed to perfect images, it’s nice to see a bit of imperfection. Of course, there can be too much of a good thing…
Me too. I end up focusing on them. The PR department needs to figure out how to add that as a feature. Use stuck pixels to lead your attention to one part of the screen.
or send hundreds of commuters to the wrong train
There is a smaller installation of one of these at the Mob Museum in Las Vegas. Cool stuff!!
thats crazy!
Not 74K pixels, but still of a decent size – http://youtu.be/rS4eiyXPICw
I hadn’t seen that before. It is pretty, though it refreshes pretty slow…
The display will only be considered defective if there are 4 dead or stuck pixels in an area the size of a quarter.
So marketing came up with a solution to make each pixel the size of a quarter.
how many people have to miss their train before they consider the display defective?
The good old sound of the dot display is SO COOL that the new LCD displays in NYC Penn Station emit a recording of that sound when the schedule scrolls.
But this one has the width and height to give that impressive 3D sound immersion.
I wonder if someone should not get some HRTF version of that effect going.
am i in italics?
p{color : red}
hello
Del *-*
Hey, aditya… enough already with your attempts to use the comment system to figure out if you can make your text change colors! post something at least borderline useful or go play with your crayons in the corner. please.
i know it was metioned before but where was the actual source of the flip dots? Its the only thing not metioned in the article.
Flipdots.com, probably. About $450 per 28*14 pixel module, if I remember correctly.
At the end of the video at the left, isn’t that Sarah Petkus? The girl with the “Robot Army” project?
https://www.kickstarter.com/projects/1984252088/robot-army-starter-kit