Custom Flex Sensors

July 25, 2009 by Zach Banks 14 Comments

flex

Flex sensors, like the ones used in the Nintendo Power Glove, are generally expensive and hard to find. However, [jiovine] demonstrates that they are easy enough to make from spare parts. He sandwiched a strip of plastic from ESD bags between pieces of copper foil, and wrapped the whole thing in heat shrink tubing. The sensor is able to detect bends in either direction, unlike the original power glove sensors. His version had a nominal resistance of about 20k ohms, but by choosing a different resistive layer you could create sensors that are more or less resistive.

Related: 5-cent tilt sensor

Pet-squirting Waterwall

July 24, 2009 by Zach Banks 8 Comments

waterwall

Sometimes, pets need to be trained to stay away from certain things. Over at sump.org, his cats needed to be kept out of his room. He used their natural fear of water by creating the waterwall, a motion-sensing device that sprays water. The project is incredibly simple and uses very few components. It is based around an IR intrusion detector and a windshield washer pump. Although that worked well enough, he also hooked it up to his computer via the parallel port so that he could take pictures as the cats (or people) are sprayed. Although the project is old, it shows how few components are really needed to achieve this kind of behavior.

Related: Motion detecting cat toy

[thanks todd]

Greenhouse Guard

July 24, 2009 by Zach Banks 15 Comments

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[Seth King] sent in his latest hack where he used an Arduino to regulate various aspects of a greenhouse. He has sensors for soil and air temperature as well as light and moisture. He built a custom circuit that uses relays to power fans, lights, and heaters. Using timers and the sensor data, the devices can be triggered to create the perfect environment for sprouts. He hopes to make the whole thing wireless by integrating XBees, but for now he ran a USB cord to his computer.

Related: Automatic grow light

Chainsaw Powered Bicycle

July 11, 2009 by Gerrit Coetzee 37 Comments

chainsawbike

We’ve covered weed whacker bicycles before and you can even buy 66cc conversion kits now. [geoff390] posted a few videos over on YouTube about another motor option. In the first video embedded below, he goes over the basic parts of his bike. The chainsaw motor is mounted to the side of the back tire and a metal drive wheel extending from the chainsaw shaft makes contact with it. The motor assembly is mounted on a hinge and the friction between the drive wheel and the back tire is adjusted with a turnbuckle. He posted a more detailed second video in which he goes over some of the finer details of the bike and some of the issues he’s had. Continue reading “Chainsaw Powered Bicycle” →

Balloon Based Satellite

July 10, 2009 by Steve Watkins 14 Comments

balloonsat

This project provides an opportunity to conduct near space experiments. The flight computer, BalloonSat Extreme, is controlled by a BASIC Stamp 2pe. The complete BOM with PCB artwork is provided. There is enough hardware to control cameras, servos, a Gps, and five digital I/O. The computer is also equipped with a 12 bit ADC to log experiment results. The device seems limited to 30KB of storage. Though the author suggests this memory limitation is more than adequate, we are wondering if an implementation of the Nyquist sampling theorem is in use at all. For further reading the author has provided information regarding Amateur Radio High Altitude Ballooning.

[via adafruit]

Hacking An IButton

July 9, 2009 by Zach Banks 36 Comments

breadboard1

Maxim’s iButtons, which are small ICs in button-sized disks, are starting to show up in more and more places. They have a range of uses, from temperature loggers to identification, and all use the 1-wire protocol to communicate. Over a furrtek, they hacked an iButton used for buying things from vending machines and created an infinite money cheat. They built a small rig based on the ATmega8 to read and write data to the chip. The data was encrypted, so it wasn’t feasible to put an arbitrary amount on the card. Instead, they used a similar technique to the Boston subway hack and restored a previous state to the iButton after something was bought. They also created a hand-held device to backup and restore the contents of a button for portable hacking.

[Thanks furrtek]

Intel 8008 Clock

July 7, 2009 by Gerrit Coetzee 11 Comments

Every year [Len Bales] designs and builds a new clock. His 2006 clock runs on the classic Intel 8008 microprocessor. The design is definitely not for the faint of heart, but he includes all code, diagrams and a good description on his site. The project is an interesting look into the not-so-distant past of computing. While the function of the project is a clock, it is actually a fully programmable 8008 computer running at 500khz with 16k of memory space and 4io ports. [Len] also links a lot of useful 8008 resources for anyone wanting to tackle a project of their own.