Quick Cheap Cassette Adapter

October 24, 2008 by Caleb Kraft 18 Comments

[Dane] sent us this super quick tape adapter project. Yes, we know we can go buy one of these for pretty cheap and it will probably sound much better, but really, wouldn’t it be cool to make one? Using a headphone adapter, a couple resisters, some wire, and an old cassette tape, [Dane] shows us how easy it is to build one of our own. You are basically pushing the signal from the headphones through a coil that is up against the tape read head. This is a perfect project to teach beginners about magnetic fields.

[Dane] has sent in some stuff before. You may recall his PWM adio generation with an AVR post several months ago.

Uv Oven From An IKEA Cabinet

October 23, 2008 by Caleb Kraft 7 Comments

This may not be an amazingly complicated project, but it is a very elegant and fairly cheap way of building a UV oven for exposing PCBs. [aris] started with an IKEA FIRA cabinet. He basically left the framework as an empty shell and made a make shift top hinged door to enclose it. Mounted in the top is an array of 35 UV LEDs powered by an HP printer transformer. He did not have a timer circuit, instead he just watched the clock and unplugged it at the right time. You can see from his pictures that his results were quite good.

If you don’t want that piece of furniture taking up room, and don’t mind using a little more elbow grease, you could follow our directions on how to make your own single sided PCB. If money isn’t an issue either, you can always just get your PCBs laser etched.

USB Authenticated Deadbolt Lock

October 22, 2008 by Caleb Kraft 29 Comments

The Makers local 256 sent us this USB authenticated deadbolt prject. For roughly $60 these guys built an authentication system that reads the serial number off of the chip in a USB storage device. The actual content on the memory in the USB device is not used at all. They are using a Freeduino board to control its behavior. It has a magnetic sensor that keeps it from initiating the lock when the door is open. They mention that they are using Transparent Aluminum as an enclosure, we assume they mean the Star Trek variety, not Aluminium oxynitride. Be sure to check out the video after the break.

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Flameless Jack-o’-lantern With An ATtiny13

October 21, 2008 by Caleb Kraft 10 Comments

[aballen] wanted to light the jack-o’-lantern this year with something that didn’t actually require fire. After searching for a project that was cheap and yielded decent results, he ended up just making his own. This project utilizes an ATtiny13 and two LEDs, red and orange. The overall build is quick and simple with some very basic code for the flickering. If you really want it more enclosed, there is this similar project using a cheap electric candle. Of course, not everyone has the time or desire to make one that is this realistic. You could always just go the easy way, no microcontroller required.

Why limit it to just lighting up your pumpkin though? Lets take a stroll through Evil Mad Scientist Laboratories hallways and see the Snap O Lantern or the dark detecting pumpkin and the Cyclonolantern.

Keyless Entry Using Touch Sensing

October 20, 2008 by Caleb Kraft 19 Comments

[Alex] sent us this slick little keyless entry system. He wanted a discreet way to trigger the door to unlock. Knocking was too loud, and would give away his secret access code. He decided that touch sensors would be the best. Initially he planned on using the doorknob itself, which would have been awesome, but it was just too much surface area for his touch sensor. Ultimately, he settled for a wire he could touch. An Arduino detects whether or not the correct code has been put in and initializes a high torque servo which turns the doorknob from the inside. In the video, after the break, you can see that it works fairly well.

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Parts: Chip Sockets For Dual In-line Package (DIP)

October 20, 2008 by Ian 14 Comments

DIP through-hole chips are an old package with instantly recognizable dual in-line pin rows. Beginners love these chips because they’re large and look easy to solder; we abhor them because we hate messing around with the drill. Whatever your motivation for using a through-hole chip, use a socket whenever possible. A circuit board with socketed chips is easy to test without endangering the parts, and ICs can be removed, tested, and replaced, without resorting to a soldering iron. This week, by request, we looked at several common through-hole chip sockets. Continue reading “Parts: Chip Sockets For Dual In-line Package (DIP)” →

Lasercut RepRap Kit

October 19, 2008 by Eliot 19 Comments

The RepRap is a self-copying 3D printer. The project has published plans for creating a lasercut acrylic version of the device. They call it a RepStrap since once assembled it could produce printed plastic versions of the machine components, bootstrapping true RepRaps. The plans are available for Ponoko an on-demand product service, and it would cost ~$380 if you used their service. The plans are free, so you could get them manufactured by other means. [vik] is still putting together the assembly instructions. He hopes to have an all inclusive electronics kit at some point too. This is another great step towards putting desktop manufacturing within reach of everyone.