Wristwatch Turntables

March 22, 2011 by Kevin Dady 7 Comments

Ever wish you could DJ on the fly while using equipment that your already wearing? Well neither have we but heck now we can, cheaply and easily with the Wristwatch Turntables. While being functional and stylish, this interesting project is fairly easy to construct and if need be, even sports a full function digital watch.

The audio electronics are donated by a pair of talking / musical greeting cards. Both, “record your own” and “just deal with what we give you” types, though which ones you choose is left up to your taste. The greeting cards are then cut apart for their hidden goodies and then a little circuit bending action is performed to monkey with the amplifier of the sound module.

Potentiometers are added, buttons are relocated, and everything gets housed in a small box, with a wristwatch ran down the middle so you can wear the whole deal and blast your funky beats anywhere you may be. Join us after the break for a quick video.

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Free Energy Is For Fools?

March 17, 2011 by Kevin Dady 27 Comments

In her new element-14 video [Jeri Ellsworth] explains some concepts about “free to you” energy and features the LTC3109EUF, an Auto-polarity, Ultra low Voltage Step-Up Converter and Power Manager, along with the LTC3588EMSE a Piezoelectric Energy Harvesting Power Supply.

Using the LTC3109EUF she is able to power a modified Nintendo Entertainment System, and LCD using a small generator and an exercise bike. The LTC3588EMSE is wired up to piezo’s in different applications including being squashed, vibrated, and temperature difference to power low current devices.

All this and a totally 80’s theme, so poof up your hair, get your spiked dog collar, and find those neon green shades because this is a fun and informative video available on element-14.

Quick And Dirty Film Dosimeter

March 17, 2011 by Kevin Dady 22 Comments

With all the talk of radiation in the media today [freddysam] posted a quick Instructable about using standard camera film as a radiation dosimeter. Film is sensitive to other forms of radiation other than visible light, and high speed films are even more susceptible due to their chemistry, which has caused all sorts of headaches to travelers before most people went digital. This uses that headache as a simple way to see if you have been exposed to abnormal amounts of radiation in a 3 step process.

Get some film. Yes they still sell it, it can still be found just about anywhere.
In a dark room unroll a little out of the metal can and put it back in its black plastic container.
Develop it if you think you have been exposed.

The idea is to let a few frames of film to be exposed to normal background radiation and develop it so you have something to compare with in the future, then you can unroll a bit more, and if you think your going into a hot area you can develop that newly exposed film to see roughly how much more radiation there was, maybe helping you sleep better at night.

LCD Twofer

March 17, 2011 by Kevin Dady 13 Comments

Inexpensive character LCDs are a popular choice for outputting data on many projects. Easily controlled , often back lit, and compact. If you have not found a reason to get one yet, here are a couple.

First up is a Programmable digital timer switch. Based around a PIC15f628A micro controller this handy little device allows you to set both on and off times to switch (light duty) devices through its relay. A standard 16×2 LCD , piezo buzzer, and 4 push buttons offer the device’s I / O. The four buttons are assigned to on / off time, select, enter, and start / stop making it easy for anyone to use. All this and sporting a clean perf-board layout which often goes out the window when using jumper wire.

Next for the AVR crowd is a LCD Name badge. Powered by a Attiny 2313 and using another 16×2 LCD, this time in blue this large, but functional name badge is ready to give out all the information people need on you while boasting your nerd credit.

Source and schematics are available for both, and yes we know these little gadgets are not exactly earth shattering so that is why we invite you to share your LCD projects on quite possibly the most awesome forum ever, the Hack A Day forums, we even have a little spot setup just for project logs.

But first join us after the break for a couple quick videos.

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Toothpaste Diode

March 16, 2011 by Kevin Dady 39 Comments

While reading the back of a tube a toothpaste [Underling] noticed that one of the ingredients was hydrated silica, gears turned, sparks flew and he wondered if he could possibly make a transistor out of the stuff. After thinking about it he decided that making a diode out of toothpaste would be easier and still prove the idea.

The quick n dirty explanation of this is he smeared some toothpaste on a bit of chrome and set it on fire with a propane torch. When set on fire the result is silica and sodium, heat causes the sodium to bond with the silica and since sodium is negatively charged this forms an n-type semiconductor or half of the diode. Chrome is used for the second half of the diode, for a few reasons, he had some lying around, its positivity charged, and the toothpaste contains a little bit of lye which oxidizes the chrome and burns off, bonding the silica to the metal.

What is left is a thin layer of chrome doped silicon under a layer of sodium doped silicon, which in spots where everything is perfect, acts like a diode, blocking current in one direction but not the other.

Motorcycle Sound Effects

March 16, 2011 by Kevin Dady 12 Comments

[Winfred] was thinking one day, of how the world would be a different place if everything we owned had little start up and shut down sounds like our computers. Historically computers would just beep after passing their power on self test, and many PC’s still do, but in the 1980’s as machines became more powerful and home users wanted more flexibility in their hardware, startup chimes started to creep into our lives. And why not extend that little moment of joy to other objects, like adding Windows XP startup and shutdown sounds to your motorcycle.

Electronically the bill of materials looks like hobby shop catalog, featuring a Freeduino (Arduino variant), Adafruit wave shield, marine speakers, and a cheap-o mp3 amplifier from ebay. While admittedly not the cheapest way to play an audio clip [Winfred] offers a few suggestions to help drop the 100$ price tag, including just skipping it all together and mimicking the sounds with your voice.

Its a fun idea, its sure to earn some odd looks from his neighbors, and it will probably make you chuckle a little too.

Animated Paper

March 15, 2011 by Kevin Dady 8 Comments

What if you could make paper react on physical input. Maybe you want it to shy away and close up if someone reaches for it too fast, or maybe you want some realistic paper flowers? Moving on to that great first step is Animated Paper, which is simply nitinol memory wire bonded to paper via our favorite tool, duct tape.

Memory wire is first bent to its desired shape, and in order for it to hold that shape it needs to be heated to about 540 degrees Celsius, which is a easy task for a propane torch. Once it has its memory shape the wire can be bent into any shape desired, and when heated to about 70 degrees Celsius will return to its original set shape.

Taped down to a sheet of paper and letting some current from a battery run though it the wire quickly warms up and animates the paper, which could be exactly what one needs in a more artsy robot or electronic display. Join us after the break for a short video.

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