Collimated Displays Wrap Around That Home Cockpit

We don’t recall having heard the term ‘collimated display’ before, but we’ve seem them in action. These are mirrored projection display that give the viewer a true peripheral vision experience thanks to well-designed optics. Here is a project that [Rob] and [Wayne] have put a ton of time into. It’s their own version of a DIY collimated display that uses a shop vac and Arduino to form the screen shape.

The frame above is the structure that will support the screen. A sheet of mylar was later attached to the edges of that frame. That is pulled into place by the suction of the vacuum. But it needs to be stretched just the right amount or the projected image will be distorted. They’ve got something of a PID controller to manage this. A valve box was built to vary the amount of vacuum suction inside the screen’s frame. A switch positioned behind the mylar sheet gives feedback to the Arduino when the screen reaches the appropriate position and a servo closes off the suction box. If you lost us somewhere in there the description in the clip after the jump will help to clear things up.

Here’s an unrelated project that implements the same concept on a smaller scale.

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Converting Transparency Sheets To An LCD Monitor

Apparently, there’s some sort of sporting event being televised this weekend that has been historically used as an excuse to buy a big-screen TV. [Joel] wanted a huge-screen TV on the cheap, so he converted an overhead projector to something he can use with his XBox.

Using a bare LCD panel with an overhead projector is a decades-old hack we’ve covered before. The basic idea is fairly simple, but we’ve never seen anything that could be considered a semi-permanent build. [Joel] started his project by picking up a surplus overhead projector for $25 and routing a cutting board to mount the LCD in. The bulb in the projector added a lot of heat, so three small fans are used to blow air between the projector glass and the LCD display.

[Joel] started off looking at the LumenLab DIY projector project, but considered that to be a terrible amount of work with a fairly high initial investment. If you don’t count the few LCDs [Joel] burned through while building his project, his projector was built for under $100. We’re loving the result and are sure it will be much appreciated at [Joel]’s LAN parties.

Overlaying Video On Encrypted HDMI Connections

[bunnie] is up to his old tricks again. He successfully implemented a man-in-the-middle attack on HDCP-secured connections to overlay video in any HDMI video stream. There’s a bonus, too: his hack doesn’t use the HDCP master-key. It doesn’t violate the DMCA at all.

HDCP is the awful encryption scheme that goes into HDMI-compatable devices. Before HDCP, injecting video overlays or even chroma keying was a valid interpretation of fair use. [bunnie] thinks that HDMI devices should have the same restrictions analog devices have, so he decided to funnel his own video into his TV.

The build uses the NeTV, a handy and cheap FPGA board with an HDMI input and output. [bunnie] got the FPGA to snoop the HDMI bus and decide if a pixel needs to be changed or not. This isn’t much different from what researchers in Germany did a few months ago, but unlike the academic security researchers, [bunnie] gives you a shopping list of what to buy.

As an example of his work, [bunnie] implemented something like a ‘tweet ticker’ on HDCP-encrypted video. There’s very little the NeTV setup can’t do from chroma keying, filters, or simply dumping the HDMI stream to a hard disk. Check out the slides from [bunnie]’s talk to get better idea of what he did.

[PAPPP] found a video of the talk in question. Check that out after the break.

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An E-paper Information Panel

With all the Kindles and Nooks we’re bound to find at yard sales and thrift shops in the coming years, this might be useful. [Chris] made a door-mounted e-paper display to keep himself up to date on recent events.

The hardware comes from an e-paper development kit [Chris] and his friend [Deian] were given a few years back. The dev kit sat in a dusty drawer until [Chris] decided to do something with it. With his door looking like a suitable palette, [Chris] decided to make an information panel that displays the date, his calendar, the weather, and a few RSS feeds.

There was already a Gumstix single board computer attached to the e-paper display, so [Chris] wrote a few scripts on his server and upload information to the paper display. The server renders the display as a PNG image at 800×600 resolution, converts it to PGM and compresses it for the Gumstix. There is a script running on the Gumstix to download the image from the server every five minutes and put it up on the display.

With the awesome readability and low power consumption of e-paper, we’re surprised we haven’t seen a project like this before. Guess we’ll have to wait until Kindles start showing up at flea markets.

3D Printed Zoetrope

Normally, 29 men walking around in an endless circle would be the stuff  of an [M.C. Escher] engraving. [Tobias] turned this into a reality with a little help from some LEDs and a 3D printer.

Like his earlier project, [Tobias] built himself a nice little strobing zoetrope that maintains the illusion of movement by flashing LEDs at precise intervals. Instead of a flat 2D image, [Tobias] went for a walking 3D figure that marches to the beat of a timer circuit. The figures themselves were printed via Shapeways.

The electronics were improved for this iteration. Formerly, [Tobias] used a 555 and a whole bunch of auxiliary components. The circuit was improved for this version to uses Schmitt triggers and an optical encoder. The easy-to-build-on-perfboard schematics and layouts are available, so feel free to build one for yourself.

[Tobias]’ zoetrope isn’t much different from the gigantic Charon sculpture seen at last year’s Burning Man. Sure, it’s not 40 feet tall but it’s still a nice piece of work.

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Projector Project Bears No Fruit But It Was A Fun Ride

No matter how good the intentions or how strong your hack-fu may be, sometimes you just can’t cross the finish line with every project. Here’s one that we hate to see go unfinished, but it’s obvious that a ton of work already went into reclaiming these smart white-board projectors and it’s time to cut the losses.

The hardware is a Smartboard Unifi 35″ computer with a projector mounted on a telescoping rod. It was manufactured for use with a touch-sensitive white board which the guys at the Milwaukee Makerspace don’t have. The projector works, but all it will display is a message instructing the user to connect the computer to the white board. Since they’ve got a couple of these projectors, it would be nice to salvage the functionality.

The first attempt was to replace the video signal to the projector. A few test boards were etched to experiment with DVI input. This included several logic sniffing runs to see what the computer is pushing to get the warning message to display. Alas, the group was not able to get the device to respond. But this opens up a great opportunity for you to play Monday morning hacker. Take a look at the data they’ve posted in the link above and let us know how you would’ve done it in the comments.

Censoring All The ‘F’ Words On TV

[Milton] sent in a build that censors every ‘F’ word on TV, and not just the one that rhymes with ‘duck,’ either. His setup sounds the alarm every time someone inside the moving picture box says a word that contains the letter F.

The build is based around Nootropic Design’s Video Experimenter Shield. This neat little shield has been used as a video sampler and has analyzed what the talking heads are actually saying. The Video Experimenter Shield has support for closed captions, meaning a transcript from a TV show can be read in real-time. All [Milton] had to do so the ‘F word’ alarm could be sounded was strchr().

The F-Chip, as [Milton] calls his build, includes three outputs – a solenoid sounds a bicycle horn, sends some air through a whistle, and lights up an ‘F-word’ alarm. From the video of the F-Chip in action (available after the break), we can tell that this build is awesome, thoughtful, and annoying. The only way it could be made more annoying is by making an ‘E-word’ alarm, but there are ways around that.

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