Video Projector From An Old Single-slide Unit

Here’s a video projector that [Matt] hacked together. He needed a small and inexpensive solution to use with his R2D2 build. As you can see in the video after the break, it has no problem playing back the Princess’ distress call. But even if R2D2 is not one of the droids you’re looking for, we think this can be useful in other ways. One use that pops into mind is for projector-based Halloween displays.

As with past projector hacks, all you really need to pull this off is a light source, an LCD screen on which you can playback video, and a lens to focus the light onto a screen. Usually the LCD is the most expensive part of the project and building an enclosure to the correct dimensions can be a bit difficult. [Matt’s] solution was to use an MP4 knockoff media player. The rest of the setup is a ’50s era slide projector. The screen from the media player is about the same size as a single film slide, so he removed the screen from the case and put it where the slides go.

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Projector Tricks Make Use Of Kinect 3D Mapping

[Don’t stop the clock] is doing some work with a projector, a camera, and the Kinect. What he’s accomplished is quite impressive, combining the three to manipulate light with your body. The image above is a safer rendition of the Hadouken from the Street Fighter video games, throwing light across the room instead of fire. This comes at the end of the video after the break, but first he’ll show off the core features of the system. You can hold up your hand and wave it to turn it into a light source. In other words, the projector will shine light on your hand, moving it, and manipulating the intensity based on hand location in 3D space. Since the Kinect is sending fairly precise data back to the computer the projected image is trimmed to match your hand and arm without overflowing onto the rest of the room until you touch your hand to a surface you want illuminated or throw the light source with a flick or the wrist. It may seem trivial at first glance, but we find the alignment of the projector and the speed at which the image updates to be quite impressive.

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Projector Introduces Augmented Reality To Reality

[Raj Sodhi] and [Brett Jones] have been working on interactive augmented reality as part of their research at the University of Illinois. What they have come up with is a stylus-based input system that can use physical objects to create a virtual landscape. Above you can see that an environment was built using white blocks. A camera maps a virtual world that matches the physical design. From there an infrared stylus can be used to manipulate virtual data which is projected on the blocks.

What they’ve created is a very advanced IR Whiteboard. There are buttons on the stylus, one of which opens the menu, made up of circles that you can see above. From there, you can select a tool and make it do your bidding. After the break there’s a video demonstration where a game is set up, using the menu to place tanks and mines on the 3D playing field. We wonder how hard it would be to do this using a projector and a Kinect.

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Servicing An Epson Projector

[Socket7] got his hands on a projector that had some color calibration problems. Of course the servicing manual says that there are no technician serviceable parts inside, but he cracked it open and fixed it anyway. This is an Epson PowerLite 5500c which was showing blue and yellow bands around the outside of the projected image. He could hear something rattling around inside which happened to be the lenses. It turns out there are foam pads that hold them in place that had shriveled over time. After a bit of careful work he replaced them and now has a working projector.

We’d love to have a projector of our own; there’s a lot of cool stuff you can do with them. Fixing a broken one is a great way to get one cheap, [Socket7’s] was free!

Wii Sensor Bar Projector

Having experienced quite a bit of trouble getting the Nintendo Wii remotes to work reliably with his home theater projector, [Sprite_TM] designed his own sensor bar replacement. If you’re not familiar, the Wii remotes have an infrared camera in the tip that sense two IR LEDs in the sensor bar that resides above or below your television. The problem is that if you’re too far away, the points of light are not where the remote expects them to be and the cursor will not perform as expected. Since this is a huge projected display it’s no surprise that the player is further away from the screen than the system was designed for.

[Sprite_TM’s] solution was to build a projection system for the two IR points. The unit in the picture above is a driver circuit with two IR emitters mounted on a heat sink, each with its own reflector. The reflected beams are shined through a Fresnel lens and projected on the same wall as the TV image. The viewer will not be able to see this light as it’s in a longer wavelength than the visible spectrum. But the Wii remote performs beautifully now and the replacement sensor bar is happily mounted out of sight above the projector.

Laser Marquee Projector

This laser message scroller is built with inexpensive parts. The heart of [Raul’s] system is a spinning pill-box with eight mirrors on it. Each redirects the laser to a different vertical portion of the projection surface. There are eight small arms on the apparatus that each break the beam of an optical sensors as it spins, facilitating the precise synchronization needed to generate the projected image correctly. In the video after the break we can make out what looks like an Arduino controlling the system. This makes sense as it’s easy to connect the laser pointer and sensor, and the USB connection allows for the streaming of messages to the system.

Want to see a more complicated setup? Check out the POV laser projector from a few years back. Continue reading “Laser Marquee Projector”

Another Home-built Laser Projector

[Jarrod] sent us a link to this home-built laser projector after seeing a different projector that we featured yesterday. This system is fundamentally different. [ChaN], who finished the project several years ago, didn’t use a loudspeaker to move the mirrors, but instead build his own closed-loop Galvanometers. Two of these are controlled by an ATmega64 to produce incredibly clean and accurate vector images. It’s not just the images that are impressive, his hardware is laid-out with skill and forethought that make hiding it in a case a sacrilege.