Above you see a solenoid being used as a digital scale. The magnetic field from the coil in the base levitates the platform above, where a load to be measured is place. This floating platform has a permanent magnet in it, hovering above a hall effect sensor in the base. As the distance between that magnet and the sensor changes, the measurable magnetic field changes as well. The hall effect sensor is linear so the measured value can easily be correlated with a weight. In the video after the break [Vsergeev] demonstrates the device using test weights to show off its 0.5 gram resolution. He thinks that with a few hardware improvements he could easily achieve 0.1g accuracy.
Month: January 2011
Our Beloved XBMC Hits IOS Devices
For those who have been longing to unlock the power of the Apple TV 2 the wait is over. XBMC is now available for iOS devices. This isn’t limited to the tiny ARM-based set-top box, but extends to the entire family including iPad and iPhone 4. Included is the ability to play high def video up to 1080p without transcoding. But we think the best feature might be XBMC’s ability to easily stream media over the network from just about any operating system. Goodbye iTunes tethering.
If you’re comfortably using SSH to work with a Jailbroken device, ATV2 installation will be a snap as there’s already a source repository to install from. iPad and iPhone 4 are even easier, just add the repository in Cydia and install. Wow, when we first looked in on the new generation of ATV we really thought it would take longer than it has to see a port of our favorite open source media client. Thanks Team XBMC!
Dance For A Dollar With The YayTM
The YayTM is a device that records a person dancing and judges whether or not the dancing is “Good”. If the YayTM likes the dance, it will dispense a dollar for the dancers troubles. However, unless the dancer takes the time to read the fine print, they won’t realize that their silly dance is being uploaded to YouTube for the whole world to see. Cobbled together with not much more than a PC and a webcam, the box uses facial recognition to track and rate the dancer.
The YayTM was made by [Zach Schwartz], a student at NYU, as a display piece for the schools Interactive Telecommunication Program. Unfortunately there aren’t any schematics or source code, but to be honest, having one of these evil embarrassing boxes around is probably enough. What song does the YayTM provide for dancing, you ask? Well, be sure to check it out here.
EDIT: [Zack] has followed up with an expanded writeup of the YayTM. Be sure to check out his new page with source code and more info. Thanks [Zack]!
Making Boxes From Soda Cans
This shiny little box was made from a soda can. You don’t need much to pull this off; an aluminum can, sand paper, scissors, a ballpoint pen, a straight edge, and some time. The embossing is done with the tip of the pen, but there’s a bit of a trick to it. The designs are first pressed into the metal from the underside of the aluminum. It is then flipped over and the outlines are traced, with one last tracing of the shape from the underside once that is completed. We think you’ll agree that this results in an impressive relief of the design.
This would make a nice project for that wedding ring you’ve been carrying around sans-case. Or perhaps this is just what you needed as an enclosure for your next project. You’ll find an instructional video after the break.
LEGO Wah-wah Pedal
Here’s a guitar wah-wah pedal that [Christian Munk] built. Inside you’ll find a circuit board that he etched and populated based on this design but he chose to build the housing out of LEGO. The video after the break gives you an idea of what it sounds like, but for those who’ve stepped on a LEGO piece with bare feet, his pedal pounding might make you cringe!
To manipulate the sound the pedal rocks forward and backward on a center pivot shown above as a grey “nut” sticking out the side of the frame. Inside there’s a system of LEGO gears that turn a trimpot to alter the sound. This might go along nicely with that guitar amp you hacked together.
Guitar Tube-amp From Junk Hi-fi
[Tristan Chambers] picked up an old speaker box some friends acquired at a yard sale. It didn’t have any inputs, and there weren’t any tuning knobs like a radio would have, so it’s a mystery what this was originally used for. [Tristan] traced out the circuit and figured out where he could input audio signals which allowed him to hook up an iPod, but it was mono and not very loud. He ended building his own vacuum tube preamp from a schematic he found on the Internet so that he could use it with an electric guitar. As the video after the break shows, the box not only puts out some pretty good sound but it’s nice and loud too.
Zipitbot
[Nulluser’s] Zipit was fine, but it couldn’t go anywhere on its own. Adding some motors and a microcontroller fixed that issue, and now he’s got a little robot called the Zipitbot. That’s a dsPIC board on top which communicates with the Zipit over an I2C bus. Four servo motors provide plenty of power to the wheels,with some extra battery packs nestled between them.
Since the Zipit is running Linux, and already has WiFi hardware, it’s not too hard to add Internet control. With this in mind there’s a webcam on the front to broadcast a video feed for use when controlling it remotely. See a couple of videos of this hack after the break.