Day: May 25, 2011

Arduino Based Biofeedback Unit

May 25, 2011 by 4 Comments

[Michael Gerstenmayer] has been very successful in developing a biofeedback system. He’s based the build around an Arduino and started adding different chunks to the project to develop a full-featured unit. It can take your temperature (with an IR sensor…. not the hard way), measure your galvanic skin response (conductance), and produce feedback based on this data. Interestingly enough, he built a peripheral vision feedback system based on the glasses frames seen above. They have an LED on each side which are illuminated based on the sensor data.

By using the Arduino’s USB connection the data can also be processed by a PC. [Michael] spent some time working with an open source program called BrainBay to gather and map the stream from the sensors.

We enjoyed reading about the build, but there’s no information about what he’s got planned for this project. That shouldn’t stop you from setting up your own rig and using it as a lie detector, or for the devilish purposes we’ve seen in the past.

PS3 Controller Spoofing Advancing With Leaps And Bounds

May 25, 2011 by 26 Comments

Development has been progessing quite nicely on [Matlo’s] PlayStation 3 controller spoofing project. This is a package that allows you to identify a PC as a PS3 controller. We know what you’re thinking: why would you want to do that? When we originally looked in on the project about a year ago we mentioned that this allows you to use any Linux-friendly peripheral as a PS3 controller. In the clip embedded below you’ll see that nothing beats a good keyboard and gaming mouse when it comes to first-person shooters. [Matlo’s] solution not only allows you to use alternative control hardware, but there’s almost unlimited configurability.

And speaking of configuration, he’s done a ton of work on the GUI. After the initial package installation no terminal typing needs to be done to get the system configured. Once in place, you can set the MAC address of a Bluetooth dongle to spoof the address of your SixAxis controller. From there you can set up the button mapping, calibrate mouse hardware and the like, and even program macros (fantastic). Now go out and pwn everyone at deathmatch now that the PlayStation Network is back up and running.

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Automated Hose Keeps Cats From Watering You

May 25, 2011 by 50 Comments

Commenter [TheCreator] reminded us of this fantastic video from [Craig Turner] who you may recognize from SBS’s Top Gear Australia Video Competition.  You see, [Craig] has been struggling for some time with the problem of neighborhood cats relieving themselves pretty much all over his stuff. Through surveillance he identified (and named) around 9 separate cats sauntering into his yard during the wee hours of the night.  The only issue now was to humanely discourage them from entering his yard.

The best solution, in this case, was a simple spray from the garden hose, but who is going to stay up all night to watch for cats? [Craig]’s ’75 Galant happens to have aftermarket door locks. These typically contain a simple powerful 12V actuator that will push or pull when given current. The actuator is strong enough, and has enough travel, to depress your typical garden sprayer handle. The lock actuators even include enough mounting hardware to tack everything together.  The only irreversible part of the hack appears to be the hole drilled into the sprayer’s handle.

The job of cat detection is handled with a PIR sensor (sourced from his home security system) and a paper towel tube to narrow the detector’s field of view. Placed at animal height the PIR detector works like a trip line, and flips a relay connected to an array of devices:  A bright LED lamp, a DSLR set to take several quick photos of the victim, An HD video camera, and the sprayer solenoid.  This whole rig is placed at a convenient choke point and hilarity ensues! A schematic is included in the video but is pretty difficult to interpret, we transcribed it for you. Some details are unclear but essentially a few relays are stapled together to provide either high or low switching signals.

Check out the video, [Craig]’s schematic, and our interpretation of [Craig]’s schematic after the jump!

Continue reading “Automated Hose Keeps Cats From Watering You” →

Color Object Tracking With An 8-bit Microcontroller

May 25, 2011 by 20 Comments

[Craig] sent in a link to this project which manages to implement color tracking on an 8-bit microcontroller at 60 frames per second. That’s some pretty incredible performance, but we’re also not talking about using a hobby-grade microcontroller. The C8051F360 is an ARM microcontroller with 100 MIPS throughput and with a system clock that can operate at up to 100 MHz. You also must consider that the chip will be able to do nothing else while in the tracking mode. Even with those gotchase, it’s still pretty incredible.

The setup uses an Omnivision OV7720 camera module. It has its own 24 MHz clock, which is used as the clock signal on the microcontroller’s PLL to generate a 96 MHz system clock. The code, which is written in a combination of C and assembly language, pushes captured tracking data to a PC via a serial port connection. After the break you can watch a bare-bones demo video that illustrates what the camera sees and what data shows up on the PC.

If you had the system in hand, what would you use it for? Perhaps it’s a perfect addition to that paintball sentry gun at which you’ve been hacking away?

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The Ins And Outs Of Lithium-based Battery Packs

May 25, 2011 by 10 Comments

lithium_batteries

So, you’ve got your awesome project built and are ready to take it on the go, but how are you going to power it? You could use a couple alkaline cells or perhaps swipe a Litihium battery pack from some infrequently used portable device – however before you do that, why not check out what [Lady Ada] has to say on the subject?

The detailed tutorial on her site discusses the different types of Lithium-based batteries and their form factors, as well as the strengths and weaknesses of each type. Voltage ratings are covered, as well as why it is important to choose a Lithium battery pack that fits the task at hand. The dangers of improperly handling batteries are clearly noted, highlighting the importance of selecting a proper charger and resisting the urge to ever wire Lithium batteries together to increase capacity.

While the bulk of the information presented is nothing new to most of our readers, it’s definitely a worthwhile read for those just starting to use Lithium battery technology in their projects.

Extracting Secured Firmware From Freescale Zigbee Radios

May 25, 2011 by 17 Comments

decapped_MC13224

[Travis Goodspeed] recently tore down the Freescale MC13224 wireless radio chip in an effort to demonstrate how the device’s firmware could be read, even when locked down in “secure” mode. While you might not recognize the Freescale MC13224 radio by name alone, you are certainly familiar with some of its practical applications. Found in the QuahogCon and Ninja Party badges among other consumer goods, the popular Zigbee radio turned out to be a fairly easy conquest.

[Travis] first used acid to decap one of the microcontrollers to see what was going on under the plastic casing. Inside, he discovered a discrete flash memory chip, which he removed and repackaged using a wedge wire bonder. He was easily able to extract the firmware, however decapping and repackaging a flash chip isn’t necessarily the most user-friendly process.

After digging further, he discovered that holding one of the chip’s pins low during boot would allow him to run custom code that recovers the firmware image once the pin is pulled high once again. This far more practical means of firmware recovery can be easily facilitated via a circuit board revision, as [Travis] mentions in his blog.

Hacked Phone Runs Zork, Gets Lamp

May 25, 2011 by 14 Comments

A few months ago, [Ulysses] had a project in mind that would run Zork on a TDD. Although it was a bit of a struggle getting the project ready in time for the Bay Area Maker’s Faire, the accompanying build blog tells us it was more than worth the effort.

After hooking up the guts of the phone to an Arduino Pro, A modem was modified so the acoustically coupled TDD could be interfaced. Although the TDD display is only one line, [Ulysses] is transmitting the text at only 45.5 baud, So even the slowest reader could keep up with the story. For running the actual code, initial attempts at using an Arduino Pro, and then Arduino Mega proved unsuccessful because of the limitations of sram in these AVRs. After discarding the idea of running Zork on an Arduino, the project was finished with a single board FitPC computer mounted inside the phone.

The code of the project runs Zork on a port of the Infocom Z-code Interpreter Program, or ZIP. A lot of interactive text adventures were put out in the Z-code format, so we’re guessing it would be trivial to have this project run Leather Goddesses of Phobos, or the amazing Hitchhiker’s Guide to the Galaxy. It’s a very nice project, and we could easily see ourselves sitting down with this project, a two liter bottle of Shasta, and an all-Rush mix tape on a Saturday night.