Transfer Data Via YouTube

August 23, 2015 by Al Williams 31 Comments

The original steganography technique dates back to 440 BC (according to Wikipedia) when a Greek wrote secret messages on a piece of wood, covered it in wax, and then wrote innocent text on the wax. The term, in general, means hiding a message in something that looks harmless. The LVDO project (and a recent Windows fork) says it is steganography, but we aren’t quite sure it meets the definition. What it does is converts data into a video that you can transfer like any other video. A receiver that knows what LVDO parameters you used to create the video can extract the data (although, apparently, the reproduction is not always completely error-free).

The reason we aren’t sure if this really counts as steganography is that–judging from the example YouTube video (which is not encoded)–the output video looks like snow. It uses a discrete cosine transform to produce patterns. If you are the secret police, you might not know what the message says, but you certainly know it must be something. We’d be more interested in something that encodes data in funny cat videos, for example.

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Cheap Projector Tells Time, Invades Space

August 12, 2015 by Richard Baguley 14 Comments

Building a video projector isn’t something that most people do casually, but [Dominic Buchstaller] isn’t most people. As part of an ongoing street art project, he built a rather neat scrap video projector/bedside lamp/clock device he calls Great Balls of Fire. It is made from a Nokia cell phone screen and a small projector mechanism, mounted inside a frosted glass light sphere.

One of the most interesting parts of the build is the projector mechanism. Rather than build one from scratch or tear apart an expensive Pico projector, [Dominic] found another source: a cheap car logo projector from eBay. These are designed to show a car manufacturer logo on the ground when you open your car door. It came with all of the parts he needed, including an LED light source and optics. He tore that apart and replaced the car logo with the phone screen, creating a very cheap projector. It isn’t that bright, but it is bright enough that when he mounted it inside the glass sphere, it could project the time and the odd space invader. It’s a great example of how sometimes it makes sense to look for a cheap solution rather than a free one: buying the car logo projector saved him a lot of hassle in building the optics. [Dominic] was also responsible for this awesome old-school tube radio hack, where he replaced the guts of an old radio with an internet radio player.

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Spools Of Thread For 6,400 Pixel Color Display

July 22, 2015 by Mike Szczys 35 Comments

This is not an LED display, it’s a thread display. The hardware artists over at Breakfast, a Brooklyn based rapid product and prototype company, built this color display that uses spools of thread for each pixel. 6,400 spools to be exact.

Loading modules into the display

Pixels use long strips for the colors

Serious work went into this thing, and the results couldn’t be better. Check out the video after the break to see for yourself. The trick is to increase the surface area of the spools of thread. This is done by using the spool as a pulley which guides a 5.5 foot length of “threaded fabric”. Up close, the fabric looks as if it’s just wrapped around the wooden spool, but the extra length provides enough room for 36 different colors, each blending into the next in a gradient effect. Index the location of the fabric in each pixel system and you have a wide range of color options.

The piece was commissioned by clothing retailer Forever 21 and has even been given its own website. The display pulls Instagram photos with the #F21threadscreen hashtag and displays them. You can watch a live stream for the next week, and the dedicated site has a search feature to find a recording of your own photo by username.

We must once again give credit for producing the kind of advertising we want to see. This is both interesting and awesome. It gave some talented people work producing it, and sharing the details of the build is both interesting and inspiring for us. Want to see some more interesting advertising like this? Check out that Beck’s bottle used as a phonograph cylinder, and the extreme engineering used to separate Oreos.

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Trick Google Used Hides Secret Messages On LCD Screens

July 15, 2015 by Adam Fabio 37 Comments

[Travis] didn’t get picked to go to Google I/O this year, but he did have some I/O inspired fun after the fact. His friends who did go told him about specially modified LCD screens Google had scattered around the event. The screens showed normal show information when viewed with the naked eye. When viewed through a special transparent badge included with the I/O swag though, a URL for Google’s scavenger hunt would magically appear. [Travis] was intrigued by the effect, and became hell-bent on reproducing it himself.

[Travis] figured out the transparent badge was actually a polarizing filter. Every standard LCD has two of them, usually bonded to the glass of the LCD itself. If you remove the filters from a LCD, you’ll get a prime view of the backlight – unless you’re wearing polarizing glasses of course. Google’s monitors didn’t have that effect though. They showed a full color display, with a second full color hidden display only visible through the polarizer

It only took a bit of three-dimensional thinking for him to figure out Google’s trick. There are actually two LCDs used in the display. The first is a standard LCD with backlight. The trick is to strip the polarizing film off a second LCD and place it in front of the first. The second LCD will be invisible to anyone – without the polarizer.

[Travis] quickly set about replicating the display using several obsolete VGA LCDs. He quickly found that the hard part was peeling the polarizing plastic from the thin glass LCD sandwich. Several LCDs gave up their lives in the effort, but in the end [Travis] was successful. He made everything fit in one case by using a thin LED backlight in a case designed for a monitor with a Cold Cathode Fluorescent Lamp (CCFL). The result looks exactly like a standard LCD – that is, until viewed through a polarizing filter. Click past the break to see the hidden message LCD in action!

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Homemade Camera Stabilizer

July 13, 2015 by Anool Mahidharia 11 Comments

We’ve featured quite a few camera gimbals and steady cams here, but this one stands out. For one, [Daniel Rhyoo] was in his sophomore year when he built it. His 2-axis camera gimbal uses brushless DC motors, and is made out of carbon fiber.

[Daniel] machined the carbon fiber parts on a CNC desktop mill and some hand tools. And he also had to teach himself Solid Works to design it. In his slick DIY guide, he starts off by listing the parts and where to source them from, along with the tools needed. Most gimbals use servos for axis movements, which limits the range and do not provide very smooth motion. Brushless motors overcome these limitations allowing a nice, smooth moving gimbal to be built with a wide range of movement. When [Aleksey Moskalenko] introduced the AlexMos brushless motor controller, [Daniel] ordered it out, and then waited until he could get his hands on the right kind of motors. CAD files for all of the machined parts are available for download (.zip file).

He then goes on to blog his build progress, with ample photos to describe the machining and assembly. He does a couple of nice design choices along the way – like using press-nuts to make assembly and dis-assembly easy, and dismantling one of the motors and replacing its shaft with a custom, longer one instead of using a coupler to extend it. At the end, the result is not only a nice looking, light weight rig, but one that works very well thanks to the motors and controller that he used. Check out the video below to see it in action.

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Build An Amazon EC2 Gaming Rig

July 10, 2015 by Brian Benchoff 44 Comments

PC gaming is better than console gaming. Now that we’ve said something controversial enough to meet the comment quota for this post, let’s dig into [Larry]’s Amazon EC2 gaming rig.

A while ago, [Larry] bought a MacBook Air. It’s a great machine for what it is, but it’s not exactly the laptop you want for playing modern AAA games on the go. If you have enough bandwidth and a low enough ping, you can replicated just about everything as an EC2 instance.

[Larry] is using a Windows Server 2012 AMI with a single NVIDIA GRID K520 GPU in his instance. After getting all the security, firewall, and other basic stuff configured, it’s just a matter of installing a specific driver for an NVIDIA Titan. With Steam installed and in-home streaming properly configured it’s time to game.

The performance [Larry] is getting out of this setup is pretty impressive. It’s 60fps, but because he’s streaming all his games to a MacBook Air, he’ll never get 1080p.

If you’re wondering how much this costs, it’s actually not too bad. The first version of [Larry]’s cloud-based gaming system was about $0.54 per hour. For the price of a $1000 battle station, that’s about 1900 hours of gaming, and for the price of a $400 potato, that’s 740 hours of gaming.

Battlezone Played On Vector Display With Hand-Wound Yoke

June 9, 2015 by Mike Szczys 7 Comments

We’ve been admirers of the work [Eric] and friends have been doing over at TubeTime for years. One of the earliest we can remember is the decatron kitchen timer, and we still tell the story of [Eric] purposely leaving out button debouncing in order to make his vector flappy bird even harder.

TubeTime is back at it this year and we had the opportunity to speak with them at Bay Area Maker Faire. The group specializes in working with old tube displays and this year’s offering was spectacular in many ways. First off, the software side of things is an emulator running on an STM32 F4 Discovery board. The chips on these boards have a pair of 12-bit DACs which are driving the X and Y of the vector displays. Code to run the original ROMs was ported from existing projects, but the audio for the games was kind of a hack to get working.

This particular display is where things get really fascinating. The tube itself was originally manufactured as test equipment for television repairmen. What’s fascinating about this is that [Eric] had to rewind the deflection yokes himself to get it working again. Luckily he documented quite a bit about his initial research into this process and his experiments to remedy some distortion issues he encountered once it was working.

Make sure to head on over to TubeTime and read their overview of the Battlezone machine. After the break we’ve also embedded a few of our own pictures as well as the interview at BAMF.

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