Desktop Email Notification Bell

July 24, 2011 by Mike Nathan 17 Comments

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Instructables user [meseta] wanted an audible notification whenever he received an email, but must have thought that his computer’s built-in sounds were lacking in some regard. To get the perfect sound that he desired, he built himself a USB-powered notification bell.

Using an off the shelf “front desk bell” and a hand made electromagnet, he constructed a bell that could be triggered whenever a message showed up in his desktop email client. The electromagnet can be triggered by a quick pulse from a microcontroller, and in [meseta’s] case, he used a Forebrain dev board. He created a filter in his email client that runs an executable each time a message is received. This executable in turn sends a message to his microcontroller via USB, triggering the bell.

While we think that the notifier could have been put together using a far less powerful microcontroller, it’s a neat idea regardless. People seem to love alternative notification systems, so we’re pretty sure this bell will appeal to many in that crowd.

Keep reading to see a short video demonstration of his email notifier in action.

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Frustrating Fun With Magnetic Levitation

July 23, 2011 by Mike Szczys 18 Comments

[Andrey Mikhalchuk] built his own magnetic levitation device and you can too… if you have the patience. He’s not using electromagnets, like the Arduino levitator or the floating globe. Instead, a pair of ceramic ring magnets and a few hours are all it takes.

The base of his device is a couple of very large ring magnets that would most often be used in speakers. It’s hard to see them in the image above because there’s an inverted plastic container obscuring them. A second (or third depending on how you’re counting) ring magnet is selected because it is smaller than the circular void in the magnetic base. It’s impossible to simply balance the magnet in the air, but spinning it is a different story. By creating a perfectly balance magnetic top, then spinning it inside the magnetic field of the base, you can leave it floating in mid-air.

Check out the video after the break. It’s a neat effect, but you really do have to have a perfect setup for it to work. [Andrey] mentions that it takes a couple of hours to fine-tune. And if the ambient conditions change slightly, it throws the whole thing off.

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Roll Your Own Toner Transfer Dice

July 22, 2011 by Mike Nathan 11 Comments

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If you happen to be in the market for some designer dice or need a set of custom dice for a game you have created, you could pay a ton of money to have them made, or you can do it yourself.

[Dicecreator] runs a blog dedicated to the ins and outs of creating DIY game and collector’s dice. This subject is not something that we would normally be interested in, but one particular item caught our interest – DIY toner transfer dice. Very similar to the process of creating a toner transfer PCB, he walks through the steps required for making your own dice with very little overhead.

The steps are likely quite familiar to those who have fabricated your own PCBs at home. He starts out with blank dice, sanding the sides down with increasingly fine sandpaper until they are ready for the transfer process. An image is printed on glossy inkjet photo paper, which is then applied to each die with a standard clothes iron. After a bit of soaking in water to remove the excess paper, the die is ready to go.

Sure it’s not exactly rocket science, but it is a cool little trick that would work quite well if you are trying to replace a lost die or if you simply want to make a fun gift for a friend.

Magic: The Gathering Nixie Life Counter

July 21, 2011 by Brian Benchoff 26 Comments

Someone sent in a tip that pointed us to this Magic: The Gathering forum thread where a user named [DistortedDesigns] made a life counter for Magic: The Gathering out of Nixie tubes. While there’s not many details for this build, it’s just too cool to be forgotten in a single forum.

The project began by etching some plexiglas. There’s some earlier examples of [DistortedDesigns]’ work that look very professional. The electronic are extremely simple – the 25 LEDs run off of 2 AA cells, and the nixies run off of 2 C cells. We were wondering when [DistortedDesigns] would drop the A-bomb, but it looks like this build doesn’t use a microcontroller.

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Intro To DC Motor Control Using The SN754410

July 21, 2011 by Mike Szczys 10 Comments

So your electronic hobby skills are coming along quite nicely but you’re not very comfortable doing more than blinking a few LEDs. Now’s a good time to try something new by driving a couple of DC motors.

You probably know that you can’t just hook these up to the pins of your favorite uC and call it good. The motors draw a lot of current (especially if they’re strained in lifting a heavy load) which would burn out your logic circuitry. Add to this the excess induced current that is generated when a spinning motor is shut off and you’re going to need a control system that can handle these dangers.

Enter the h-bridge motor driver. [Chris] has guided us through the process of building and using a H-bridge in the past. This time he’s using a motor controller that has four half H-bridges built into it. He hooks up the SN754410 to two motors, giving him speed and direction control for both based on the duty cycle of a PWM signal entering the chip for less than $2.50. Check out the video after the break for an overview of his methodology, then work your way through the multi-page post that he recently published.

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Amazing Pipe Organ Desk Features Secret Compartments And An All-wood Logic Board

July 20, 2011 by Mike Nathan 38 Comments

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Feeling pretty good after putting together your brand new standing computer desk? Step aside please, [Kagen Schaefer] has something he’d like to show you.

His Pipe Organ Desk is undoubtedly one of the coolest pieces of furniture we have seen in a long time. The project took [Kagen] over three years to complete, which sounds about right once you see how much attention was put into every last detail.

This desk is amazing in several ways. First off, the entire desk was constructed solely from wood. The drawers, the supports, knobs, screws, and even the air valves – all wood. Secondly, when one of the desk’s drawers are pushed in, air is directed to the organ pipes at the front of the desk, which plays a note.

A small portion of the air is also directed into the desk’s pneumatic logic board, which keeps track of each note that has been played. When someone manages to play the correct tune, a secret compartment is unlocked. The pneumatic logic board is an unbelievable creation, consisting of well over 100 wooden screws which can be tuned to recognize any number of “secret tunes”.

Sure a well-placed axe can open the compartment too, but who would destroy such a fine piece of work?

[via Make]

Chilean Teen Builds Automatic Earthquake Alarm

July 19, 2011 by Mike Nathan 27 Comments

When an earthquake is about to strike in Chile, who do you think is first to sound the alarm? You might be surprised that it’s not the government, but rather a 14 year old boy.

After living through an earthquake in 2010 and seeing the devastation this spring in Japan, Chilean teenager [Sebastian Alegria] decided that he wanted to construct something similar to Japan’s earthquake warning system. He purchased an off the shelf earthquake detector for less than $100, and connected it to his computer via an Arduino.

Now, whenever seismic activity is detected, his sensor tweets an alert letting his 29,000+ followers know that a perceptible earthquake is 5 to 30 seconds away. Apparently the Chilean government is working on a similar system that is still at least a year away, so in the meantime his fellow citizens rely on [Sebastian] instead.

While it might seem like a relatively easy hack to pull off compared to other earthquake detectors, we’re impressed by [Sebastian’s] creativity, and his will to help others. He’s been pounding away at computers since he was about 4 years old and has several other popular Twitter-based projects under his belt already, so we won’t be surprised if we hear from him again in the future.