PIC Powered AVR Programmer

[Texane] wrote in to let us know he has implemented AVR ISP programming using a PIC microcontroller. He wrote some code for an 18F4550 that uses the STK500 standard for In System Programming. This means that his hardware is compatible with AVRdude, the open source AVR programming software. There has long been an argument over the virtues of PIC versus AVR but we say why not both? If you have already honed your programming chops with PIC, you can build your own programmer and give the Atmel family a try.

The current implementation uses a serial port to connect the programmer to a computer. Keep your eye on this one as [texane] plans to add USB connectivity and has told us he will post schematics for the device as soon as that is complete.

Linear Optical Encoder

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Optical encoders are nothing new; they can be found in everything from mice to printers. They’re great for allowing DC motors to know their exact position and even current direction. If this is sounding like old hat, it’s because we’ve shown you rotational versions before.

[Chris] uses the same concept, but produced a linear optical encoder instead of rotational. His setup is much like whats used in non stepper-motor CNC and RepRap mills, allowing ordinary DC motors to know their position within a plane. It’s a quick tutorial, but we liked the detail and it reminded us we need to finish that DC motor based mill thats still a pile of parts in the closet. Check out a video of [Chris’] in action after the break. Continue reading “Linear Optical Encoder”

Homopolar Motor

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Slow day at the office?  Here’s a trick that’ll make your coworkers smile. Dangerously Fun has a guide to build a homopolar motor from a battery, copper wire, and magnet. A homopolor motor doesn’t rely on electromagnets in an armature changing their polarity to force a rotation movement compared to stationary magnets. Instead, they use an electrical current’s orientation to a magnetic field to provide a repulsive or rotational force.  In this implementation, the current moves through a loops of copper wire from one pole of a battery to the other.  A rare-earth magnet on one pole of the battery provides the magnetic field.

After the break we’ve embedded video of this simple example as well as a few more complex homopolar examples such as a five speed version.  The motor in action certainly brings a smile to our faces and places this firmly in the useless machines family of hacks.

Continue reading “Homopolar Motor”

Servoelectric Guitar Is A Keytar With Strings

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[Keith Baxter] has undertaken something of a ‘Mount Everest’ of guitar modifications. He’s developing a Servoelectric guitar that trades frets for a keypad. It is still a guitar in the sense that it has a body, strings, and pickups to sense the strings vibrations and pass them to an amplifier. The left hand, which traditionally would shorten the strings as needed by pressing them against a fret, now changes string pitch using a keypad. This is an interesting fusion between traditional guitar and 80’s phenomenon, the keytar.

Each string is connected to a different servo motor. When a key on the keypad is pressed, the corresponding servo adjusts the tension of that string, bringing it in tune at the new pitch. His original design involved a lot of custom circuitry but he’s evolved the project to include an Arduino controller. This second generation both simplifies the control circuitry and improves upon it.

We’ve embedded some video after the break. In the first example you can see the strings adjusting for each new pitch. In the second, take a look behind the guitarist… what do you think he’s got planned for those giant capacitors?

Continue reading “Servoelectric Guitar Is A Keytar With Strings”

25 Scariest Experiments

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Warning: This video contains actual footage of a severed dog head, kept alive. Watch at your own peril.

[Annalee] over at io9.com has gathered together the 25 scariest science experiments.  There are some truly frightening pieces, like the cyborg beetles which we’ve seen before, all the way to silly stuff like the guy who re grew his thumb using pig powder. Next time you’re thinking of admonishing someone for creating a flamethrower, or a super fast scooter, consider for a moment that they’re not burning peoples nasal passages to stop masturbation or creating zombie severed dog heads like the one in the video above.

Ping-pong Launcher Your Wife Can’t Know About

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Sometime the projects you see at the local hacker space are better left a secret when you return home for the evening. Case in point, this ping-pong ball launcher that can put holes in a sheet of OSB. The projectile is made more lethal because the ball has been injected with water to dramatically increase the density. Compressed air is used to propel it from the 14 round magazine with devastating effect.

We’ve embedded a video of the gun being fired after the break. The creator, [Ron Kessinger], demonstrated this at a Denver hacker space called Club Workshop. We’re hoping there’s no plans for turret automation because this thing’s dangerous! Either way, the significant other who usually watches out for our safety would never approve. Continue reading “Ping-pong Launcher Your Wife Can’t Know About”

We’ll Take The Fries.

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We’ve all been there; hardest decision we’ve ever had to make. College and debt or freedom but no career? Start a family or live out alone? The number 2 with a small shake or side of fries?!

[Leon] sent in his random number generator, oddly enough not to just generate a number, but help us through with those life altering decisions. Using a noise diode like setup he’s able to generate random bits, which an ATtiny24 then converts and displays on a 7 segment LED. His generator also has the ability to set upper and lower limits. Seems like an awful lot of work to avoid the freedom of choice paradox, but we enjoyed the project none the less. Check out a video after the break. Continue reading “We’ll Take The Fries.”