Catch Neighborhood Speeders With Your Webcam

May 31, 2012 by Mike Szczys 54 Comments

[John] is keeping the neighborhood safe by keeping an eye out for speeders. Well, he’s really keeping a webcam out for speeders. His technique doesn’t use radar or lasers. He’s processing webcam frames in Python to calculate speed.

It comes down to some basic image manipulation. He firsts gathers the images necessary to make the calculations by using a motion-detecting webcam program called YawCam. The images are analyzed to establish which parts have changed between frames; this gets rid of all the stationary objects. Now the frames can be compared to establish the distance in pixels. By calibrating the shot through measurements of the target area, this data can be directly converted into actual distance. It is then compared with the timestamps from each frame to arrive at speed. This can be used for vehicles on the street like we see above, or more whimsical measurements like pet turtle progress.

Building Your Own Eye In The Sky

May 28, 2012 by Mike Szczys 22 Comments

His goal of one post a week for a year has past, but [Dino] keeps bringing his skills to bear on new projects. This time around he’s adding a wireless camera to an RC helicopter.

These radio controlled fliers (there are cheap ones that use IR control which is much less reliable) can be found for around $30-60. [Dino] already had a wireless camera to use, but adding it and a 9V battery is just too much weight to lift. After some testing he established that 2oz of payload is the upper limit. He began removing parts from the helicopter to achieve enough savings to lift both the camera and its battery. Along the way he discovered that removing the weights from the fly bar added a lot of maneuverability at the cost of a small stability loss.

Check out his project video embedded after the break. It’s not anywhere near the results of professional multi-rotor camera mounts, but it is cheap and fun!

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Automatic Airplane Tracking; What Radar-systems Engineers Do For Kicks

May 4, 2012 by Mike Szczys 15 Comments

[G. Eric Rogers] is a radar-systems engineer who just happens to live within sight of the aircraft approach path for the local airport. We wonder if that was one of the criteria when looking for a home? Naturally, he wanted his own home-based system for tracking the airplanes. He ended up repurposing a motorized telescope for this purpose.

The system does not actually use Radar for tracking. Instead, the camera strapped to the telescope is feeding a video experimenter shield. A tracking algorithm analyzes the video and extrapolates vector data. From there, the base unit can be controlled by the Arduino via an RS232 interface.

There are some bugs in the system right now. The Arduino has something of an ADHD problem, losing interesting and going to sleep in the middle of the tracking process. [Eric’s] workaround uses the RS232 board to periodically reset the Arduino, but he hopes to squash this bug soon.

Watch A Shop Tour Through The Screen Of An Oscilloscope

May 3, 2012 by Mike Szczys 7 Comments

[Alan] posted a video tour of his electronics shop, but you’ll be viewing it through the green screen of an oscilloscope. The image above is a video camera filming a scope screen which displays the image of…. an oscilloscope (insert your own Yo Dawg meme here). But first he shares the technique he uses to display composite video on an oscilloscope screen.

The first three minutes of the video after the break are devoted to the video display hack. He starts with a glimpse of the breadboard circuit which takes the composite video signal and provides the necessary X, Y, and Z input signals to the scope to perform like this. He then walks through each portion of the schematic, which is based on an LM1881 video sync separator chip. The horizontal and vertical sync signals are separated by this chip, then filtered to produce ramp voltages for each to drive X and Y. The Z-axis is fed through a simple inverter circuit; Bob’s your uncle and your oscilloscope is now a TV monitor.

Of course this is not the first time this has been done. But we loved [Alan’s] presentation, and thought the shop tour was a fun way to finish off the video.

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RCA Capacitive Electronic Disk

May 1, 2012 by Jeremy Cook 25 Comments

Although not a hack in the sense that it was made by a large corporation, check out this capacitive electronic disk that [danielbpm] wrote in about. Here’s a Wikipedia article about it, as well as a video (which didn’t embed correctly) about how it was made. The disks look like a typical audio record, and it was conceived of in 1964. A prototype was manufactured in 1972.

Unlike the more well-known Laserdisk format, the [Capacitive Electronic disk], or [CED] used an actual stylus to read the disks. Because of this, the [Wikipedia] article astutely points out that both systems were mutually incompatible. Somewhere there might have been a scratched Laserdisk next to the VCR with a sandwich stuffed in it. The computer with a broken coffee holder wouldn’t come for another few years.

Although it may have been a good format in it’s own right, like Betamax or HD-DVD, this system wasn’t destined to become the Blu-Ray player of it’s time.

MIT Students Take Tetris To A Grand Scale

April 23, 2012 by Mike Szczys 28 Comments

Careful, this hack might foster doubts about the level of fun you’re having at you own Computer Science department. Last weekend a group of students at MIT pulled off a hack of great scale by turning a building into a Tetris game board.

The structure in question is the Green Building on the Massachusetts Institute of Technology Campus. It houses the Earth, Atmospheric, and Planetary Sciences Departments, but was chose based on the size and regularity of the grid formed by the windows on one side. The group hasn’t provided much in the way of details yet, but the video after the break shows the game play and start-up screen. The middle portion of the building is used as a scrolling marquee to display the word “Tetris” before the game pieces start falling. We’re only guessing (and we hope you will add your conjecture in the comments section) but we’d bet they assembled a set of wireless RGB LED lamps and set one on the sill of each window. There does seem to be a number of ‘dead’ pixels, but it doesn’t diminish the fun of the overall effect.

If you don’t have your own building to play on, you should go small-scale and implement Tetris on a character display.

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Stop Motion Animation Creation

April 23, 2012 by Jeremy Cook 4 Comments

Stop Motion Animation has always been interesting to me since I “discovered” that one could make animated flip books by drawing each frame a little different. Fast forward 20 years or so, and computer technology has gotten to the point where this sort of thing can be done electronically quite easily and at an incredibly low price of a camera, computer, and free or paid-for software (here’s the technique using GIMP, a free, good quality photo editing tool) to put everything together.

The frames in the picture above are of my latest [PVC man] animation, which can be made with some electroluminescent lights, gloves, and some PVC pipe. Each frame was individually photographed, and after several hours of work we had enough footage for 17 seconds of so of stop-motion animation.

Although by no means perfect, the quality of these animations has gone up dramatically from the first animations that I made using an old ENV2 camera phone. Although I was using a “custom mount” for it, it’s amazing these came out as well as they did. As with everything hacking related, this process is a constant work in progress. Check out the videos after the break for the [PVC man] video as well as one of the early ENV2-produced stop-motion shorts!

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