DIY Film Projector Fits In The Palm Of Your Hand

March 17, 2012 by Mike Nathan 11 Comments

DSLRs aside, the price of digital cameras these days can make it easy to consider just tossing your old one out when it breaks. [Leonidas Tolias] had another idea, and with a few broken cameras he had on hand he constructed a slick little pocket-sized projector.

The project started out as a pair of lenses from busted cameras and an Altoids tin in which he mounted them. The larger lens from a video camera was installed on the exterior of the tin, while the smaller of the two was mounted inside. Bits from disposable cameras were used to create a set of film reels, which he supports with some hand cut scrap aluminum. He made some test photo slides by printing some images on transparency paper, which he can cycle through using a film advancement rig he built out of string and a couple of gears.

While you won’t be using this projector for your next boring PowerPoint presentation, it does work pretty well as you can see in pictures on [Leonidas’] site.

[Thanks, Taylor]

Projector Calibration On Uneven Surfaces Made Easy

February 29, 2012 by Mike Nathan 18 Comments

projector-calibrator

If you are thinking of building your own flight/racing sim setup at home, you might want to check this out. [Alex] from the Garoa Hackerspace in Säo Paulo, Brazil put together a slick setup that makes projector image calibration a breeze.

When building a wraparound screen for such a simulator, you are likely to run into problems with both overlapping images and distortion from the curved projection. There are projectors that can easily adjust themselves to work in this sort of setup, but they are often very expensive, so [Alex] thought he would build a solution himself.

After studying a paper written by [Johnny Chung Lee] in 2004, he built a prototype display calibrator last year that used similar, though slightly tweaked methods to get the job done. This time around, [Alex] has improved his calibrator, making the process more precise and a bit quicker.

Light sensors and an Arduino are attached to the back of the projection medium, and a large broad scan of the screen is performed by the projector. His code then triggers an additional sweep of each corner to better estimate the exact edges of his projection surface. Since the video is tweaked in software rather than relying on the projector hardware to handle the task, the result is cheap and very accurate.

Don’t take our word for it though, check out [Alex’s] video demonstration below to see his calibrator in action.

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Control Android With A Projector And Kinect

January 25, 2012 by Brian Benchoff 5 Comments

If you’re going to build a giant touch screen, why not use an OS that is designed for touch interfaces, like Android? [Colin] had the same idea, so he connected his phone to a projector and a Kinect.

Video is carried from [Colin]’s Galaxy Nexus to the projector via an MHL connection. Getting the Kinect to work was a little more challenging, though. The Kinect is connected to a PC running Simple Kinect Touch. The PC converts the data from the Kinect into TUIO commands that are received using TUIO for Android.

In order for the TUIO commands to be recognized as user input, [Colin] had to compile his own version of Android. It was a lot of work, but using an OS designed for touch interface seems much better than all the other touch screen hacks that start from the ground up.

You can check out [Colin]’s demo after the break. Sadly, there are no Angry Birds.

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Projector Project Bears No Fruit But It Was A Fun Ride

January 9, 2012 by Mike Szczys 18 Comments

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.

RGB Laser Projector Is A Jaw-dropping Build

November 10, 2011 by Mike Szczys 45 Comments

We can think of no better way to describe this laser projector project than Epic. [C4r0] is a student at Gdansk University of Technology and he’s been working on this projector for at least a couple of years. It uses several different laser diodes pulled out of DVD burners, Blu-Ray drives, and entertainment equipment (the green diode is from a disco laser).

In order to direct the beams he built a series of brackets that hold dichroic filters which reflect some wavelengths of light while allowing others to pass straight through. Each diode also needs a driver, most of which he built from scratch. And once the hardware has been designed and tested, what does one do with it? If you’re [C4r0] you build it into a money case with professional-looking results.

Don’t miss the video demo after the break. And make sure you have a rag ready to wipe up the drool before you look at his forum post linked above.

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Old-school Projector Turned Digital

October 31, 2011 by Brian Benchoff 21 Comments

Who hasn’t thought about turning a 1950s slide projector into a digital projector? [Matt] did, but unlike most of us, he actually did it.

[Matt]’s friend [Angus] found an old, single-slide, sans-carousel slide projector in the trash. It’s a wonderful piece of ancient technology with a fabric insulated power cord and bakelite lamp socket. This projector was upcycled to the 21st century by adding a 10 Watt LED and a Nokia 1200 LCD.

For the electronics, [Matt] used an ATmega88 microcontroller. There’s an infrared receiver so the remote from an in-car CD player can be used to advance the slides and turn the projector on and off. The LCD is controlled by a bit of bit-banging from the Mega88, using hard-coded images of Che Guevara, Hendrix, Space Invaders and some old-school Macintosh/Lisa icons. Unlike the screen printed t-shirts at American Apparel, Che is the only authentic image in this project; this projector might have been made after Guevara came to prominence.

With a 10 Watt LED, it’s not the brightest projector on the planet and the picture is a little washed out in a bright room. With dim lighting, it’s a very good project even if the images are static.