You have an old PC with a nonstandard RGB video out and you need to bring it to a modern PAL TV set. That’s the problem [svofski] had, so he decided to use an Altera-based DE1 board to do the conversion. Normally, you’d expect reading an RGB video signal would take an analog to digital converter, which is not typically present on an FPGA. Instead of adding an external device, [svofski] used a trick to hijack the FPGA’s LVDS receivers and use them as comparators.
If you want video support on your project, you might start from a device like a Raspberry Pi that comes with it built in. [Kevinhub88] doesn’t accept such compromises, so he and his Black Mesa Labs have come up with a whole new way to add video support to devices like the Arduino and other cheap controllers. This project is called Mesa-Video, and it can add digital video at a resolution of up to 800 by 600 pixels to any device that has a single serial output.
The video is created by an FT813, a low cost GPU from FTDI that offers a surprising amount of video oomph from a cheap, low power chip (he has demoed it running from a lemon battery), meaning that he is hoping to be able to sell the Mesa-Video for under $50.
UPDATE: [KevinHub88] let us know that he didn’t actually power the device from a lemon battery, as you would need a lot of lemons to make 50mA at 5V. Apologies for any confusion!
However, Mesa-Video is just the beginning. [Kevinhub88] wanted to get around the problem of stacking shields on Arduinos: add more than one and you get problems. He wanted to create an interface that would be simpler, faster and more open, so he created the Mesa-Bus. This effectively wraps SPI and I2C traffic together over a simple, fast serial connection that doesn’t require much decoding. This means that you can send power and bi-directional data over a handful of wires, and still connect multiple devices at once, swapping them out as required. You could, for instance, do your development work on a PC talking to the prototype devices over Mesa-Bus, them swap the PC out for an Arduino when you have got the first version working in your dev environment. Is the Arduino not cutting it? Because Mesa-Bus is cross-platform and open source, it is easy to swap the Arduino for a Raspberry Pi without having to change your other devices. And, because all the data is going over a simple serial connection in plain text, it is easy to debug.
It’s an ambitious project, and [Kevinhub88] has a way to go: he is currently working on getting his first prototype Mesa-Bus devices up and running, and finalizing the design of the Mesa-Video. But it is an impressive start and we’ll be keeping a close eye on this work. Hopefully he can avoid that head crab problem as well because those things are as itchy as hell.
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.
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.
Continue reading “Cheap Projector Tells Time, Invades Space”
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.
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.
Continue reading “Spools Of Thread For 6,400 Pixel Color Display”
[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. [Travis] is intelligent and experienced, so 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!
Continue reading “Trick Google Used Hides Secret Messages On LCD Screens”
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.
