Motors And Microcontrollers 101

[youtube=http://www.youtube.com/watch?v=WnWJki-zwsE]

[Humberto] from NerdKits sends in the newest addition to their excellent collection of videos. This video goes over the basics of DC motor control with microcontrollers. They begin by showing nine experiments and observations that can be done by the average hacker with a multimeter, motor, LED, and jumperwire. Using the results from these they show how to model and calculate the properties of a motor. Lastly, it shows how to control a motor using PWM. They have supplemental text and demonstration code for an ATmega168 on their website.

AVR RFID Tag

[pc486] sent in his hack that uses an ATtiny85 to act like an EM4102, a chip used for RFID tags. Minimally, all that is needed is the AVR and a coil, but he recommends some filtering capacitors. Depending on the size of the coil, different frequencies and ranges can be achieved. This project actually includes several hacks, such as using the coil for not only power, but a clock signal. The coil is actually able to power the chip without being connected to the power pins due to clamping diodes on the connected pins. The firmware is short but available on subversion.

Related: Scratch-built RFID tags

64 Synchronizing Fireflies

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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

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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.

Arduino Nixie Shield

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Reader [Bradley] sent in his ArduiNIX project, an Arduino shield designed for driving nixie tubes. The shield allows the Arduino to drive and multiplex nixie tubes without any additional hardware. These antique-looking displays are commonly hacked into clocks. It takes 9 volts from a wall wart and steps it up to over 200V in order to drive the displays. The shield is capable of multiplexing up to 80 individual elements. He has example code for driving a 6-digit display and a clock on his site. He is selling kits and completed shields too.

Related: Victorian nixie tube clock

[thanks Bradley!]

USB Reader For SNES Game Carts

[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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