Trashed LCD Monitor Turned Into A Light Box

May 8, 2013 by Mike Szczys 30 Comments

light-box-from-lcd-monitor [x2jiggy] was given a non-functioning LCD monitor. He made a small effort to trouble-shoot its inability to display anything on the screen but couldn’t get it working again. When that failed he decided to repurpose it as light box instead of just sending it off for recycling.

Monitor manufacturers put in a lot of effort to make sure the back lights distribute brightness as evenly as possible and that will make this a pretty good light box. [x2jiggy] starts off the conversion by removing the case. While it was off he gave it a new coat of paint. The LCD panel, the PCB that drives it, and the light diffuser sheets were all removed, leaving just the backlight and inverter PCB. A bit of probing with the multimeter and he even found a place to connect a toggle switch to actuate the inverter’s power. You can see the silver switch he added to the bezel in the image above. The full build video is embedded after the break.

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Video Player Built From Stellaris Launchpad

April 27, 2013 by Mike Szczys 11 Comments

stellaris-launchpad-playing-video

We think it’s pretty impressive to see a Stellaris Launchpad playing back Video and Audio at the same time with a respectable frame rate. It must be a popular time of year for these projects because we just saw another video playback hack yesterday. But for this project [Vinod] had a lot less horsepower to work with.

He’s using a 320×240 display which we ourselves have tried out with this board. It’s plenty fast enough to push image data in parallel, but if you’re looking for full motion video and audio we would have told you tough luck. [Vinod’s] math shows that it is possible with a bit of file hacking. First off, since the source file is widescreen he gets away with only writing to a 320×140 set of pixels at 25 fps. The audio is pushed at 22,400 bytes per second. This leaves him very few cycles to actually do anything between frames. So he encoded the clip as a raw file, interlacing the video and audio information so that the file can be read as a single stream. From the demo after the break it looks and sounds fantastic!

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Connect A Retina Display To A Regular Computer

April 22, 2013 by Mike Szczys 99 Comments

You don’t have to search very long before you find someone raving about the Retina display used in Apple iPads. We’re not going to disagree. These 9.7″ panels pack in a whopping 2048×1536 resolution and the color is fantastic. But we were surprised to hear you can get one of these for a meager $55. That’s how [Andrzej] sourced the part when he set out to connect a Retina display to a regular PC.

It turns out this isn’t all that hard. The display uses the eDisplayPort protocol. This is an extension of DisplayPort which is an alternative to LVDS that is gaining a foothold in the industry. An external DisplayPort adapter can already be found on higher-end laptops, which means this should be a snap to use as an external display if the signals can be routed correctly.

To do this, [Andrzej] figured out how to order the PCB connector for the panel’s ribbon cable. He then etched and populated his own board which serves as an adapter for a DisplayPort cable. It even powers the panel, but an external 20V supply is necessary for the backlight.

[Thanks Adam]

GUI Window Manager On An AVR Chip

April 20, 2013 by Mike Szczys 31 Comments

avr-window-manager-gui

This project is reminiscent of the old days when window managers were an amazing new idea. The difference is that this window-based GUI is running on an ATmega1284 microcontroller. But the behavior and speed of the interface is pretty much exactly what you’d expect if working on an early 90’s home computer. It even uses a mouse as input.

So how is this even possible? The key to the project is a serial to VGA module which handles the heavy lifting involved with generating a VGA signal. We featured one of [Andrew’s] past projects which used an AVR chip to generate the VGA signal. But that doesn’t leave nearly enough cycles to implement something like a window manager, not to mention the fact that it got nowhere near the resolution shown here.

He uses a serial mouse with an RS-232 converter chip to interact with the windows. This is best shown in his video after the break. He’s able to generate and interact with new windows. He even implemented a set of rudimentary controls which allow him to adjust the theme of the windows and drive the audio playback feature included on that VGA controller he’s using.

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Dual Displays On A Playstation 2

April 2, 2013 by Brian Benchoff 19 Comments

scope

At the Revision 2013 demoparty held last weekend, visitors and guests wanting to check out the latest advances in programming old video game consoles got a real treat. [Abyss] took a Playstation 2, connected the composite video out port to a TV and an oscilloscope, and created the first dual display PS2.

From the official video of the demo, the two video signals are generated from a single video out on the PS2. Generating the composite video out is understandably fairly easy, but the second display – an oscilloscope – is driven during the Vblank period in the composite signal. There’s no audio trickery here; video signals are used for video, and audio signals are used for audio.

[Abyss] took first place in the wild demo competition at Revision 2013. Understandably, too, because this is one of the best demos we’ve ever seen. You can check out the official video from [Abyss] after the break, and the wild competition video after the break.

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AVR VGA Generator

March 29, 2013 by Mike Szczys 19 Comments

avr-vga-generator

This simple circuitry makes up the hardware for [Andrew’s] AVR-based VGA generator. He managed to get an ATmega1284 to output a stable VGA signal. Anyone who’s looked into the VGA standard will know that this is quite an accomplishment. That’s because VGA is all about timing, and that presented him with a problem almost immediately.

The chip is meant to run at a top speed of 20 MHz. [Andrew] did manage to get code written that implemented the horizontal and vertical sync at this speed. But there weren’t enough clock cycles left to deal with frame buffering. His solution was to overclock the chip to 25 MHz. We assume he chose that because he had a crystal on hand, because we think it would have been easier to use a 25.174 MHz crystal which is one of the speeds listed in the specification.

Red, green, and blue each get their own two-bit range selected via a set of resistors for a total of 64 colors. As you can see in the video after the break, the 128×96 pixel video is up and running. [Andrew] plans to enlarge the scope of the project from here to make it more versatile than just showing standard images. The code (written in assembly) is available at his GitHub repository.

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Color NTSC Video Directly From An AVR Chip

March 27, 2013 by Mike Szczys 27 Comments

color-ntsc-from-avr-chip

We’ve seen composite video out from AVR chips many times before. But we can’t remember coming across one that managed to produce a color signal. This project does just that, producing a color video signal from an ATmega168 without using external integrated circuits.

[CNLohr] is seen here showing off his accomplishment. You’ll remember him from the glass-slide PCB server project he’s been working on recently. This time around it’s a small piece of gaming hardware which he’s working on. But using four pins from the microcontroller, connected via resistors in parallel, he is able to generate a color NTSC signal without using a chip like the AD723.

After the break you can see the two minute demo in which he shows the game running for just an moment, then gives a general overview of how the signals are being built. There isn’t a ton of explanation, but he did post his code as well as a resource for you to teach yourself more about the NTSC standard. Maybe you can make a color version of that AVR tetris game?

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