Adding Persistent Memory And Ethernet To Vintage Arcade Machines

May 27, 2011 by Mike Nathan 13 Comments

z80_bus_tapper

If you are a frequent reader, you are undoubtedly familiar with hacker [Sprite_tm]. He has been working with fellow members of the TkkrLab hackerspace to get things ready for their official grand opening on May 28th, and wrote in to share a project he recently completed to kick things off.

As part of their preparations, they have been stocking the joint with all sorts of hacker-friendly goodies including plenty of tools and Club Mate, as well as a vintage ‘1943’ arcade cabinet. The game is a group favorite, though every time the power is turned off, it loses all of the hard-earned high scores. [Sprite_tm] knew he could improve on the current paper-based score register, so he pulled the machine open to see what could be done.

He used an AVR to tap into the machine’s Z80 logic board, allowing him to read and write to the entirety of the game’s RAM whenever he pleased. This enabled him to keep tabs on the high scores, restoring them to memory whenever the machine is powered back on. The addition of the AVR also allowed him to add a TCP/IP interface, which is used to send high scores to Twitter whenever someone beats the previous record.

His modular bus tap can be used in all sorts of Z80-based hardware, so if you have some vintage equipment laying around, be sure to swing by his site for a more detailed look at the build process.

Low-cost, Low-bandwidth Wireless Arduino To Android Communications

May 27, 2011 by Mike Nathan 22 Comments

android_nfc

[Joe] was experimenting with his Arduino when he started thinking about how he could get it to communicate wirelessly with his Android phone. Bluetooth is an option, but it requires some extra components, and Google’s ADK works as well – just not wirelessly.

Instead, he thought it would be neat to see if he could get the two devices to communicate with a simple magnetic coil. He constructed a small 1cm diameter coil, connecting it to the Arduino via a resistor and diode. Using the Android Tricorder app, he was able to locate his phone’s magnetometer, after which he ran some tests to narrow down the best sample rate and frequency range for communications.

To transfer data between the two devices, he had to bit bang the signal in software, since the Arduino’s UART has a lower limit far faster than the 7 bps data rate he was able to achieve with the magnetometer.

While his wireless Arduino to Android bridge isn’t likely to win any awards for throughput, it is a great proof of concept project. Be sure to check out the video below to see his “poor man’s NFC” in action.

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My Desk IS My Computer Case

May 26, 2011 by Mike Nathan 39 Comments

If you think that your water cooled rig is pretty sweet, check out this creation by Dutch PC enthusiast [Peter Brands] (Google Translation).

With his computer tweaked as far as he could imagine, he decided to spruce up his office a bit. In the process, he ended up tweaking his computer just a little bit more. After seeing a build put together by another computer enthusiast, he set off to construct a desk in which he could show off his computer. He spent some time drawing up plans with Google Sketchup and with the help of a friendly neighbor, started construction of his desk/PC case.

The desk is constructed from 3mm thick aluminum, and houses most of his computer’s components under a thick piece of glass. The only portion of the computer that is not enclosed in the desk is the 9-fan radiator he used for his water cooling setup. That part resides in his crawl space, which he connects to his PC via a pair of large water hoses he punched through his tile floor. If you are interested, you can see all 800+ pictures of the build here.

Simply awesome!

[Thanks duchie]

Tracking Eye Movement By Measuring Electrons In The Eye

May 26, 2011 by Brian Benchoff 14 Comments

[Luis Cruz] is a Honduran High School student, and he built an amazing electrooculography system, and the writeup (PDF warning) of the project is one of the best we’ve seen.

[Luis] goes through the theory of the electrooculogram – the human eye is polarized from front to back because of a negative charge in the nerve endings in the retina. Because of this minute difference in charge, a user’s gaze can be tracked by electrodes attached to the skin around the eye. After connecting eye electrodes to opamps and a microcontroller, [Luis] imported the data with a Python script and wrote an “eyeboard” application to enable text input using only eye movement. The original goal of the project was to build an interface for severely disabled people, but [Luis] sees applications for sleep research and gathering marketing data.

We covered [Luis]’ homebrew 8-bit console last year, and he’s now controlling his Pong clone with his eye-tracking device. We’re reminded of a similar system developed by Atari, but [Luis]’ system uses a method that won’t give the user a headache after 15 minutes.

Check out [Luis] going through the capabilities of his interface after the break. Continue reading “Tracking Eye Movement By Measuring Electrons In The Eye” →

Wall Climbing Robot Uses Supersonic Grippers

May 26, 2011 by Mike Nathan 10 Comments

supersonic_wall_gripper

Watch out Spidey, there’s a new wall climber in town!

Researchers [Matthew Journee, XiaoQi Chen, James Robertson, Mark Jermy, and Mathieu Sellier] recently unveiled their wall climbing wonder bot at the 2011 IEEE International Conference on Robotics and Automation. Like most other wall climbing bots, theirs operates on the Bernoulli principle to keep it stuck to the surface, but that’s where the similarities end.

Unlike other Bernoulli-based climbers, this robot’s gripper never actually touches the surface it is climbing. The researchers were able to accomplish this feat by designing a specialized gripper which forces air through a 25 μm gap, creating a very powerful low pressure vortex. The gripper’s design compresses the air by shape alone, causing the air flow to reach speeds of Mach 3, without relying on powerful pumps or increased air volume.

The researchers state that their supersonic gripper can support about five times the weight of a conventional Bernoulli gripper, and as you can see in the video below it also has no problem climbing a wide variety of surfaces.

Window-washing Roomba, here we come!

[via Make]

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Hey OEMs, Arduino Controlled Dishwasher Has Much Potential

May 26, 2011 by Jesse Congdon 44 Comments

I think we can all agree that sometimes projects are a bit of a stretch. We rack our brains for something interesting and unique to bring to the table and end up stretching for that special strange twist trick or technique that will garner that special kind of admiration from our peers. In that sense it is easy to loose sight of some of the best projects, the simple ones that prove you can fix anything anytime anywhere and improve it while you are at it.

This is just such that kind of project, [UnaClocker] had a washer fall victim to its own condensation. Instead of shelling out a ton of money for the repair man he took on the job himself, fitting the washer with an Arduino, relays and a breadboard. A little reverse engineering revealed the (notably well labeled) control board, evidently the control signals involved are extremely easy to interpret. [UnaClocker] also found a temperature sensor to control dish sanitation. At this point he had FULL CONTROL over the dishwasher and was able to design the ideal prewash/wash cycle timings.

Now that a wash cycle is all set [UnaClocker] can now go ahead and embarrass the hell out of the OEM. He plans on adding a real time clock module to time washings and a clean dish indicator, after which we think he should get rolling on some wireless/tweet/ethernet/capacitive touch/voice communication. After that he is going to work on buttoning up the design and making it pretty.

Check out the setup in action after the jump!

Continue reading “Hey OEMs, Arduino Controlled Dishwasher Has Much Potential” →

Hidden Messages In Audio

May 26, 2011 by Kevin Dady 24 Comments

[Alex] tiped us off about the evil sounding noises coming from http://www.thedarkknightrises.com/. when you go there your pretty much greeted with a wav file and if you have a quick eye on the status bar its pretty easy to get the direct link to the file and download it. Thats all great, but why would you want to?

Well if you play back the file in a program that supports spectrograms (like audacity) you will find that there is a twitter hash hidden within the audio spectrum, that presents itself as plain text in a pretty well rendered font. Of course this leads you to another part of the site where yet another puzzle awaits you.

While this is all an interesting way to stir up buzz about the upcoming (Batman) movie, we found hiding plain text in an audio file pretty wild, though its been done before or better such as the post we had not too long ago about Ham’s packing QR codes in a similar way.