Line Following Robot

December 14, 2005 by 17 Comments

robot

[Greg] has been doing a great job updating DIY Live. The latest entry details a line following robot. These bots are quite common, but Greg provides really thorough coverage of all of the details involved. His particular design features two separate sensors and when the robot reaches the end of the line it will reverse, retracing its steps. He’s got wiring schematics for the h-bridge and other components. He admits that PIC programming is a topic too broad for one post, but he does discuss a few of the necessary logic chunks involved.

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Micro Railgun

December 13, 2005 by 48 Comments

micro railgun

While some railgun projects are attempting to be the biggest and baddest, this one just wants to be functional. It’s not efficient or powerful, but it is really easy to put together. The barrel is constructed from two 3″ long pieces of aluminum weld bar with heavy duty Lucite sandwiched in between. The gap is only 1/16″. A disposable camera charging circuit plus 4 capacitors salvaged from other cameras provide the power supply. The projectile is a tiny piece of aluminum foil. It may not be the greatest gun ever made, but it looks like it would definitely be a good demo unit. Here is a coral cache of the site.

[thanks luke]

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Fast Serial LCD Interface

December 12, 2005 by 13 Comments

serial lcd

This is a serial interface for any LCD using the incredibly common 44780 controller. There are a couple different serial interfaces like this on the market, but this project aims to be a superior version. It can use 5 – 30V with an included regulator. It has ESD protection. True RS232 levels mean you can use really long cables. Up to 8 buttons are also supported. This would work great with a car computer. All of the software and schematics are provided. Have a look around the madhacker site for a lot of other cool projects.

[thanks Stuart]

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2.4Ghz Field Strength Meter

December 11, 2005 by 20 Comments

strength

This is a really simple way to measure WiFi strength. Actually, it will measure anything in the 2.4Ghz range, like your microwave. The device consists of a two element quad antenna, a Ghz sensitive diode and a variable capacitor for tuning. The sensor is plugged into a voltmeter for measurement. The page has links for locating the specialized diodes.

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Powerbook Compact Flash Drive

December 10, 2005 by 27 Comments

powerbook

This Powerbook 150 was purchased as a simple media reader. Once the hard drive failed the owner decided to replace it with a compact flash card since IDE adapters were available. There was a problem: the ATA device driver would probe the device and then immediately shutdown because the “identify device” bit wasn’t the expected value. The device driver had been written before more recent changes to the ATA spec. Greg solved the problem by constructing a daughter card that plugs into the adapter board’s 40-pin header and then flips the identifying bit when the device is initially probed.

[thanks iamdigitalman]

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Lumenlab Projector Build

December 9, 2005 by 38 Comments

projector

A couple days ago we mentioned that Lumenlab had released their top secret plans for building an LCD based projector. Hack-A-Day reader [Brad O’Connor] sent along his experiences using the Lumenlab plans. Like most people, he says that the $20 price of admission is worth it. The system uses a 400Watt metal halide lamp as a light source. A fresnel lens straightens the light before it passes through a consumer LCD panel. A second fresnel lens directs the light to the final focusing lens. You can grab a torrent of the plans here. Brad is currently working on motorizing his 120″ screen.

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Rotary Pinhole Camera

December 8, 2005 by 10 Comments

rotary pinhole camera

Pinhole cameras use a tiny pinhole as their aperture instead of a lens. Fran?s Besson designed this camera to take a 240 degree panoramic picture. The camera aperture slot rotates on one axis while the film rotates on a separate axis. The 8×20″ film is attached to a large drum mounted to the second spindle. The exposure length can be 18, 6, or 3 minutes depending on the voltage supplied to the drive motor.

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