[Antonb] added 10-bit encoding to a standard servo. He’s removed the potentiometer, separated its shaft and used it to rotate a small magnet. By sandwiching an AS5040 rotatory encoder IC into the servo’s housing he can now measure the precise orientation of the servo horn. This is made easier by his tiny breakout board for the chip. If you want to layout your own PCB you can download the EagleCAD files for this device. Take a look at the final product in the clip after the break.
Continue reading “10-bit rotary precision for servos”
[Freeload] sent us his custom MagSafe adapter build for laptops. MagSafe for those unaware is Apples (patented) power adapters that prevent damage to laptops when the cord is accidentally yanked from the socket. While we’ve seen some custom versions before of MagSafes they were usually bulky, ugly, and used a ton of unremovable glue. We really like [Freeload’s] because its quick, good looking, and the best part – completely removable without marks or damage. In short, an easy weekend project that could one day save your laptop.
Here’s an interesting concept, the bot pictured above has no internal control mechanisms. His claims to have built the smallest bot are dubious, considering it requires a much larger control platform to function, so lets just set that aside and look at how it works. The bot itself is basically a hollow box with a hinged manipulator mounted on it. He has then built a modified CNC type structure with various magnets below a platform. The magnets can move the bot and control the manipulator (assuming the bot isn’t trying to pick up anything magnetic). He talks about this being a possible control scheme for smaller bots, though we think he would have to make some major advancements to his magnetic controls for accuracy’s sake. As for his claims of being the smallest, well, we’re sure we’ve seem similarly sized bots, even hexapods, that were completely self contained.
After building a USB magnetic stripe reader, [David Cranor] has found a way to fool a magnetic stripe reader using a hand-wound electromagnet and an iPod. The data on a card is read and stored on a computer, then encoded as a WAV file using a C++ program. The iPod plays the WAV file with the data through a single-stage opamp amplifier connected to the headphone jack. The amplifier is used to drive the electromagnet. Video embedded after the jump.
By no means is this a new idea. There have been a lot of magnetic stripe projects and software. This project in particular references the 1992 Phrack article “A Day in the Life of a Flux reversal” by [Count Zero].
Don’t get your hopes up just yet on strolling through high security installations using this little device. It can only replay the data from a card that has been recorded. If you don’t have a known working card, it won’t get you very far.
Continue reading “Magnetic stripe card spoofer”