64 Synchronizing Fireflies

June 25, 2009 by Zach Banks 14 Comments

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[Alex] of tinkerlog created a set of 64 RGB fireflies that synchronize to blink all at once. We covered the kit earlier, but he has assembled a set of 64. Each firefly is independently controlled by an ATtiny13 that reads a phototransistor and lights up an RGB LED. The fireflies are programmed to blink a certain rate, but blink faster if they detect other blinks. After a few cycles, the fireflies begin to blink in unison. When the fireflies are arranged in different configurations, different patterns emerge. He is selling kits and has instructions for building your own. Videos of the fireflies after the jump.

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Keychain GPS Finder

June 25, 2009 by Steve Watkins 7 Comments

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With a user interface consisting of two buttons and a three digit display, the GPS finder guides the user back to a saved location. Nine locations can be saved for navigation recall. Press a button to save location and press another button to recall. Each switch has a secondary function, for management purposes such as memory indexes and power features. An AarLogic GPS 3A module and AVR microcontroller make up the guts. With the popularity of Geocaching, this would make an impressive trinket; Leading the hunter to an undocumented treasure.

EVIC Engine

June 24, 2009 by Steve Watkins 45 Comments

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The EVIC is a computer controlled internal combustion engine, utilizing a cam less solenoid actuated valve system. In addition to intake and exhaust valve control, the processor also handles ignition timing. With dynamic valve timing, it is possible to make an engine more efficient. Where a classic combustion engine would wastefully burn fuel, the EVIC can skip power cycles which are not needed. By increasing the valve duration, the CPU enables easy starting. The latest is the EVIC Mk3 which adds an exhaust valve sensor, and 3:1 solenoid leverage. There is a photo gallery with several EVIC engines. The Mk2 Twin is demonstrated in the video embedded below.

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Wireless Arduino Cat Food Dispenser

June 24, 2009 by Gerrit Coetzee 14 Comments

catfooddispenser

Reader, [Andres Leon], has two adorable cats with very specific dietary needs. Instead of altering his schedule, he donned his hacking hat and designed a very solid cat food dispenser. The dispenser consists of a rotating drum with a slot in it and a PVC pipe Y-fitting to distribute the food evenly. The brains of the machine is an Arduino Deumillanove and an XBee module. The unit can be controlled by a web interface or it can run completely standalone. [Andres] ran into a problem where the drum’s resistance to turning varied based on how much food was inside. He solved this with a clever laser position indicator. A piece of plywood is lined up with the slot at the top so that whenever the slot is facing up it keeps the laser from shining on a photoresistor. The cats were afraid of the servo noise at first, but now they run to their bowls whenever they hear it.

USB Reader For SNES Game Carts

June 19, 2009 by Gerrit Coetzee 82 Comments

[youtube=http://www.youtube.com/watch?v=Pwq6vRM8U7k]

Reader, [Matthias_H], sent in a video about his USB adapter for SNES game carts. All you have to do is plug in the SNES game cartridge and USB cable, then a ROM file of the game shows up as an external storage device on your computer. After that, you can play the ROM with your choice of emulator. We emailed [Matthias] asking for more information, and he quickly replied with a very nice writeup about the hack that is pasted below.

Update: [Matthias] launched a site for the “snega2usb” with updates on the development of the board and a FAQ.

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Meat Thermometer Using Predictive Filtering

June 17, 2009 by Gerrit Coetzee 20 Comments

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The guys over at NerdKits put together a really informative video on a meat thermometer using predictive filtering which is viewable below. The video, supplemental text, and code is available on their website. The thermometer is constructed of a LM34 temperature sensor attached to a piece of 12 gauge solid copper wire. The thermometer signal is processed on an ATmega168 microcontroller and visualized using the pygame library for python. The real gem in this project is their excellent explanation of predictive filtering, which could easily be utilized for a large number of projects.

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Arduino Experimentation Kit

June 16, 2009 by Zach Banks 8 Comments

ARDX

[Oomlout] has created an Arduino Experimentation Kit that uses basic sensors, buttons, and LEDs to teach electronics and programming. Printed overlays are secured on a breadboard, indicating components and connections. The Arduino is then used to drive the circuit. Examples include driving motors, using shift registers, and making beeps with a piezo element. These are backed up by explanations and code. The breadboarding kit is very similar to the classic 300-in-1 project kits marketed to beginners. In addition, all of the materials are released as open source. Kits are also available that include everything needed to create the circuits.

Related: Opensource Robotic Arm

[via Hack a Day flickr pool]