Oscilloscope Thinks It’s A Video Monitor

March 30, 2011 by Jeff Katz 13 Comments

There is nothing wrong with your television set. Do not attempt to adjust the picture.

Where would we be if we listened to advice like that? [Eric] writes that with a fairly simple circuit, he’s able to split a composite video signal into its constituent X and Y ramp signals for display on his trusty Tektronix 465m. A LM1881 IC does the bulk of the heavy lifting. After running the signal through a few passive components, the generated ramp signals are ready for consumption by his venerable ‘scope. All that’s needed past that is some additional glue logic to invert the levels so the image shows up properly. The end result is a display that has an almost ethereal quality to it, like an old TV set or something out of the movie Brazil.

Hit the break to catch a video of the circuit in action.

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Kinect Two-fer: MoCap Movie And Robot Control

March 26, 2011 by Mike Nathan 6 Comments

kinect_twofer

It’s no mystery that we like the Kinect around here, which is why we’re bringing you a Kinect two-fer today.

We have seen video hacks using the Kinect before, and this one ranks up there on the coolness scale. In [Torben’s] short film about an animation student nearly missing his assignment deadline, the Kinect was used to script the animation of a stick figure model. The animation was captured and built in Maya, then overlaid on a separate video clip to complete the movie. The overall quality is great, though you can notice some of the typical “jitter” that the Kinect is known for, and there are a few places where the model sinks into the floor a bit.

If you want to try your hand at animation using the Kinect, all of the scripts used to make the movie are available on the creator’s site for free. [via Kinect-Hacks]

Our second Kinect item comes in the form of a gesture driven Lego MindStorms bot. Using OpenNI along with Primesense for body tracking, [rasomuro] was able to use simple motions to drive his NXT bot around the house. His movements are tracked by the Kinect sensor which are translated into commands relayed to the robot via his laptop’s Bluetooth connection. Since the robot has two motors, he mapped couple of simple arm motions to drive the bot around. We’ll be honest when we say that the motions remind us of Will Farrell’s “Frank the Tank” scene in Old School, but [rasomuro] says that he is trying to simulate the use of levers to drive the bot. Either way, it’s pretty cool.

Videos of both hacks are embedded below for your perusal.

If you are interested in seeing some more cool Kinect hacks be sure to check out this Minecraft interface trio, this cool Kinect realtime video overlay, and this Kinect-Nerf gun video game interface.

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Video Experimenter Shield

March 24, 2011 by Kevin Dady 15 Comments

People always want to do more with less and the Video Experimenter Shield is no exception. Consisting of an LM1881 video sync separator, a handful of passive components, and a stylish PCB in the standard Arduino shield footprint.

The board features simple but useful controls and features, a removable jumper allows you to select a sync source, either from incoming video or the Arduino, a potentiometer to adjust the analog threshold, and there is a convenient signal breakout header.

Software is an enhanced version of the popular TV out library and allows you to start off with video graphics overlay, closed caption decoding, a simple gun game, and basic, but still effective frame capture, and computer vision. Of course, there are all sorts of other fun and amusing experiments that start to pop in mind once you check out a quick demo video after the break.

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Real-time Wireframe Video Effect Overlay With Kinect

March 23, 2011 by Mike Nathan 15 Comments

linedance

[Francois] over at 1024 Architecture has been working on a project we think you’ll be likely to see in a professional music video before too long. Using his Kinect sensor, ha has been tracking skeletal movements, adding special effects to the resulting wire frame with Quartz Composer. While this idea isn’t new, the next part is. He takes the QC tweaked video stream and then projects it back over the performer using MadMapper to match the video to the body movements, recording the resultant display.

The project started out with a few hiccups, including a noticeable delay between the body tracking and the display. It caused the performer to have to move more slowly than he would like, so things had to be tweaked. [Francois] first tested the latency between his computer and the projector by displaying a timecode representation on the screen as well as via the projector. He found the projector to have a latency of 1 frame at 60 fps, which wasn’t too bad. This led him to believe the culprit was his Kinect, and he was right. There was a 6 frame delay, so he locked the video output to 30 fps in hopes of cutting that delay in half.

The effect is slightly reminiscent of Tron, but with more distortion. We can’t wait to see more projects similar to this one in the future.

The resulting video embedded below is pretty cool in our opinion, but you can judge for yourself.

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Junkyard Jumbotron Is Begging To For An Open Source Project Clone

March 18, 2011 by Mike Szczys 17 Comments

Idle developers of the world take inspiration from this project and unite to create your own version. It’s called the Junkyard Jumbotron because it takes many different displays and allows them to be used as one big interactive display. The image above shows a collection of smartphones displaying a test pattern. The pattern is unique for each device and is used to calibrate the display. Using a digital camera, a picture of these test patterns is snapped, then sent to the server. The server calculates the position of each of the screens, then sends the correct slice of a large image back to each phone.

It’s funny that they use the word Junkyard in the name of the software. Each display needs to be able to run a web browser so you can’t just use junk displays. But one nice side effect of the hardware requirements is that you can still do things like panning and zooming as seen in the video after the break. Here’s the real question: can you make this work as an open source project? How about something that can be easily set up to work with a LAMP server?

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Bill Hammack Explains How LED Backlit LCD Monitors Work

March 17, 2011 by Mike Szczys 14 Comments

We had a basic understanding of how LCD monitors worked, and you may too. But the thing is, [Bill Hammack] doesn’t just explain the basics. Since he’s the Engineer Guy he explains the engineering principles behind how LED backlit LCD screens operate. But he does it in a way that everyone can understand.

After the break we’ve embedded his five-minute video. In it you’ll see him strip down a monitor to the back plate and then build it up piece-by-piece. We enjoyed his discussion of how the diffuser panels work together to even out and distribute the light. Theses are made of several layers and, although we knew they were there from working with salvaged LCD screens, we never knew quite what they were doing. He also covers how each liquid crystal cell works along with polarizing sheets to either block or allow light passage. And he’ll bring it on home by show how thin-film transistors in each subpixel of the screen work to multiplex the display, just like we did with that pumpkin back in October.

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AV Test Box Meets The Incredible Shrink Ray

March 17, 2011 by Mike Nathan 7 Comments

mini_avtester

[Chris] recently finished building a miniscule AV Test Box, capable of fitting inside a standard Altoids tin. It is a revision of a project he constructed a few years ago. His previous test box worked well, but was large and cumbersome – definitely not something you would want to carry around from place to place with any frequency.

The new test box does everything its predecessor is capable of, which includes displaying an 800×600 VGA test pattern as well as generating sound signals for testing audio systems. He updated the circuit design a bit, employing a newer PIC processor to run the show, otherwise most of the design details have remained the same, form factor aside.

His build log is full to the brim with details as usual. You will find thorough descriptions of all the components he used, schematics, source code, as well as the theory behind the build.

Be sure to check out the video embedded below of his new AV tester in action.

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