This flimsy case isn’t going to protect your Raspberry Pi if you knock it off the workbench. It will provide a level of protection against shorting out from contact with metal objects, or from liquids spilled in the near vicinity. [CGPatterson] ended up making this case from a single sheet of transparency film.
The project is basically papercraft. He started with the dimensions published on the Raspberry Pi FAQ, which turned out to be wrong. Not having a caliper available to help with the precision of the measurements, he grabbed his ruler and did the best he could. The first two cases were a poor fit, but as you can see the third is like a glove. Luckily you don’t have to go through this same trial and error as he release the design. Both A4 and US Letter sized PDFs are available for download. Print them out on the transparency, cut along the lines, apply transparent double-sided tape to the tabs and you’re in business. If you wish to alter the design he has also posted the SVG source he made in Inkscape.
This is certainly a good option for those of us without the ability to produce laser cut parts.
We recently saw how easy it is to perform basic I/O using the BeagleBone. Those techniques are in play here, used to drive a character LCD and sample a button input from the breadboard circuit. [Nuno] even published separate posts for each of these peripheral features.
The password protected PDF file is passed to the device on a thumb drive. Since the BeagleBone is running embedded Linux you don’t need to mess around with figuring out how to read from the device. A click of the button starts the process. Currently the code just uses a brute force attack which can test more than 6000 four-character passwords per second. This is quite slow for any password more than four or five characters long, but [Nuno] does mention the possibility of running several ARM processors in parallel, or using a dictionary (or rainbow table) to speed things up. Either way it’s an interesting project to try on the hardware. You can see his video demo of the device after the break.
[Satiagraha] let us know that Texas Instruments(TI) has given out a neat “LED Reference Design Cookbook” PDF. The document contains 17 some odd little projects featuring different TI ICs and ways of using them to control LEDs in things from backlights to torches to solar lanterns to advanced PWM control! Sure the document is biased towards using TI equipment, but that shouldn’t stop you from recreating, modifying, and generally just having fun with their designs in your own productions.
Facebook’s internal valuation was revealed this week thanks to shoddy PDF redaction. Court documents from a settlement between Facebook and ConnectU showed that Facebook values itself at $3.7 billion, much less than the $15 billion that was speculated during the Microsoft investment. The AP uncovered this by cutting and pasting from the redacted court document. It’s the same thing we showed in our PDF redaction screencast last summer… and it will never cease to be funny.
For some reason the PDF is redacted with black boxes. We threw together a simple screencast (click through for HiDef) to show how to easily bypass the boxes using free tools. You can simply cut and paste the hidden text and images can be copied as well-no need to break out Illustrator. This sort of redaction may seem trivial, but the US military has fallen victim to it in the past.
[Jason S. Babcock] and [Jeff B. Pelz] put together this paper on building a simple, lightweight eyetracker (PDF) to foster the creation of open source eyetracking software. All of the components are mounted to a cheap pair of safety glasses. The eyetracker uses a technique called “dark-pupil” illumination. An IR LED is used to illuminate the eye. The pupil appears as a dark spot because it doesn’t reflect the light. A bright spot also appears on the cornea where the IR is directly reflected. An eye camera is mounted next to the IR LED to record the image of eye with these two spots. Software tracks the difference between the two spots to determine the eye orientation. A laser mounted to the frame helps with the initial calibration process. A scene camera placed above the eye records what the eye is viewing. The video from these two cameras can be compared in real time or after the experiment is concluded.