A One-bit Processor

March 1, 2012 by Mike Szczys 30 Comments

Put on that abstract thinking cap, get out the pen and paper, and spend some time figuring out how this one-bit processor works. [Strawdog] came up with the concept one day during his commute to work (don’t worry, he takes the train… much safer than [Dave Jones’] frightening drive-time podcasts). He sketched it out on paper to make sure he knew where he was going with the project, then collaborated with Legion Labs to implement it in processing as an easier way to visualize its functionality. Since it’s one-bit there’s only room for one instruction. That instruction is a copy, then branch-if instruction. It copies the current bit to one address, and if that bit was one, it branches to a second address.

Going a bit fast for you? We think the description is fairly good, but if you can’t quite put it together from the article’s description, you may want to build this 2-bit paper processor and learn how it works first. It should teach you the basic concepts you need to understand the 1-bit version. As you can see in the image above, there’s also a single-step feature in the processing example that lets you analyze the effects of each instruction during program execution.

Building A Flex Sensor From Component Packing Materials

February 28, 2012 by Mike Szczys 10 Comments

Hacks like this one don’t help us recover from extreme pack-rat behavior. Driving home the point that one should never throw anything away [Peter] built a flex sensor from component packing material. It uses the black conductive foam in which integrated circuits are sometimes embedded for shipping. Above you can see the grey rectangle which is the sensor itself. in the background of the image, each component used in the build is labelled except for the tape.

The project starts with the foam being cut to the appropriate size and thickness. He does the same with some aluminum foil, then rips tape strips to act as the enclosure. Fine wire from some cable shielding serves as the two conductors for the sensor. He attaches each wire to an upturned piece of tape, followed by the foil, and finally the foam. When the two halves are assembled in the video after the break, [Peter] hooks up his multimeter to show the change in resistance as the sensor is bent.

We think it will take a clever calibration algorithm to get this working reliably, but it’s no more troublesome than the optical flex sensors we saw in this links post. Continue reading “Building A Flex Sensor From Component Packing Materials” →

Reprogramming Promotional USB Dongles To Launch Custom URLs

February 28, 2012 by Mike Nathan 16 Comments

webkey-hacking

The teachers at [Jjshortcut’s] school were each given a Webkey by the administration as a promotional item of sorts, but most of the staff saw them as useless, so they pitched them. [Jjshortcut] got his hands on a few of them and decided to take one apart to see what made them tick.

He found that the device was pretty simple, consisting of a push button that triggers the device to open the Windows run prompt, enter a URL, and launch Internet Explorer. Since the microcontroller was locked away under a blob of epoxy, he started poking around the onboard EEPROM with his Bus Pirate to see if he could find anything interesting there. It turns out he was able to read the contents of the EEPROM, and since it was not write protected, he could replace the standard URL with that of his own web site.

While it’s safe to say that without a new microcontroller the Webkeys probably can’t be used for anything more exciting than launching a browser, [Jjshortcut] can always reprogram the lot and drop them in random locations to drive some fresh traffic to his web site!

[Thanks, Wouter]

Hacking Hack A Day With Greasemonkey

February 25, 2012 by Mike Nathan 49 Comments

Ever since Hack a Day first emerged on the scene in 2004, the site’s design has been pretty consistent. The black background with its green and white text, while a bit dubious looking at work, is fine by me. For others however, the site’s design is a constant eyesore both figuratively and literally. [James Litton] is one of those readers, and he wrote in to share a tip that helps him read up on the latest hacks without killing his eyes.

[James] uses Firefox to browse the web, so he whipped up a small Greasemonkey script that tweaks Hack a Day’s style sheet once it reaches his browser. His script inverts the background while changing a few other items, making for a much more comfortable read. Overall we found the change to be pretty reasonable, but go ahead and judge for yourself – you can see the before and after screen shots in greater detail on his site.

[James] also points out that the script should work just fine in Chrome, for those of you who prefer that browser instead.

So if your eyes are a bit on the sensitive side, feel free to grab his script and customize away – I don’t think we’ll be changing the theme any time soon.

Rotating Platform Makes Most Useless Machine Concept Useful

February 24, 2012 by Mike Szczys 13 Comments

[Valentin] used a simple concept to build this auto-reversing rotating platform. The concept is extremely simple, the leads for the motor are attached to a double-pole double-throw switch which allow the polarity to be reversed. Flip the switch in one direction and it spins clockwise. Flip it in the other direction and it spins counter-clockwise.

In this case, he’s harnesses the power of the most useless machine. That often seen hack uses a similar switch, but accomplishes nothing by having the moving parts act as the actuator. This one is useful, taking advantage of a single or double arm to flip the switch and make the platform spin backwards. In the video after the break you can see it’s used to create a scanning security camera. But [Valentin] also shows it at work as a turntable for salable goods. We think’s the gearing is a little brisk for both purposes, but slowing it down is a hack for another day. Continue reading “Rotating Platform Makes Most Useless Machine Concept Useful” →

A TV-B-Gone With A PIC Twist

February 23, 2012 by Mike Nathan 14 Comments

pic-tvbgone

[Kayvon] thought that the TV-B-Gone was a fun little device and wanted to build one, but he didn’t have an AVR programmer handy. Rather than picking up some AVR kit and simply building a replica, he decided to give his PIC skills a workout and build a Microchip derivative of his own.

The PIC-based TV-B-Gone is pretty similar to its AVR-borne brethren, featuring a PIC24F08KA101 at the helm instead of an ATTiny. His version of the TV-B-Gone can be left on indefinitely, allowing him to situate the device in a convenient hiding place to wreak havoc for as long as he likes.

[Kayvon’s] TV-B-Gone does everything the original can at just under $7, which is quite a bit cheaper than the Adafruit kit. If you’re not averse to perfboard construction, be sure to check out the build thread over in the Adafruit forums. [Kayvon] has done most of the heavy lifting for you – all you need to do is build it.

Worried About Haloween This Year? Why Not A Giant T-Rex Costume?

February 23, 2012 by Jeremy Cook 12 Comments

Although some might note that [Jamie]’s creation could mistaken for a Velociraptor or even Allosaurus, his giant T-Rex costume/model is quite a feat of artistry. It stands at over 14 feet tall and 10 feet long. For comparison, the room that you see in the picture above measures 25 x 25 feet. If you happen to live in the Atlanta area, or are willing to travel, this costume is expected to make an appearance at Dragon*Con in 2012, so be sure to look for it there.

The whole thing is made from poly foam plank cut with a CNC router. It also has a metallic support structure. As noted in the article, you could, in theory, cut all these parts out by hand. Persistence would be required though, since there are over 140 parts!

[Jamie]’s making capabilities are obviously quite advanced at this point, but he’s trying to expand them by winning a router in the Instructables Shopbot contest. If you like his creation, be sure to vote for him! Check out the video of this costume in action after the break. Continue reading “Worried About Haloween This Year? Why Not A Giant T-Rex Costume?” →