Misc Hacks

4179 Articles

Magnetic Stripe Card Spoofer

August 4, 2008 by 25 Comments

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 mangetic 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.

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Build A Simple Bat Detector

August 4, 2008 by 8 Comments


[Tony Messina] had been fascinated with bat’s echolocation since he was a kid. After he retired, he decided to act on this fascination and built a simple bat detector.

The simple bat detector uses frequency division to lower the bat’s chirping to a frequency we can hear. For example, if a bat is calling at 91kHz the system will divide it by 16 and put out 5.7kHz. The system is digital, so all amplitude is lost. You’ll just hear clicks like a Geiger counter. Being digital has its advantages though. Unlike similar analog devices that have to be tuned to a small frequency range, the simple bat detector can detect a much wider window.

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CNC Wood Router

August 3, 2008 by 16 Comments


[GlacialWanderer] has published the first pictures from his CNC machine build. It’s a three axis gantry style machine that he intends to route and engrave wood with. He’s posted a detailed cost breakdown: $1800. He estimates spending 30 hours researching on sites like CNCzone. The build time for the mechanical side was around 50 hours. The electrical system hasn’t been hoooked up yet, so look for that in a future post. It looks like an incredible machine already, so we can’t wait to see what’s next.

New From SparkFun

August 3, 2008 by 3 Comments


SparkFun is rolling out interesting things to play with every week. They’ve added a NanoMuscle actuator that uses a shape memory alloy to lift nearly 70 times its own weight. Their LilyPad collection has expanded to include small momentary switches and a thermistor type temperature sensor. Lastly, they’ve got an FM receiver module. It just needs an antenna and uses I2C or SPI for control.

About:config Hacks For Firefox 3

August 3, 2008 by 9 Comments

Blogs DNA has some great suggestions for tweaking the Firefox 3 about:config file. Customize Firefox 3 to your particular preferences with hacks to reduce the number of auto-complete list in your URL bar, extend spell check to forms, and disable blinking text. All it takes is a few simple modifications to the about:config file. By editing the about:config file, you can have a Firefox 3 that is faster, less bloated, and more tailored to your browsing habits. Do you have any suggestions for tweaks to Firefox 3?

[via Digg]

Apple Newton Dev Kit?

August 3, 2008 by 3 Comments


[phooky] picked up this bizarre bit of dev hardware three years ago and isn’t really sure what it is. It has lots of general purpose switches, LEDs, and audio jacks. The processor is a StrongARM chip in a ZIF socket. It has two serial ports, a CF, and PCMCIA slot too. Commenter [Glen Raphael] says it looks a lot like the early prototype development boards for the Apple Newton which also used a StrongARM chip. It’s definitely an interesting piece of history. Make sure you check out the full item on NYC Resistor.

Laser Etching Printed Circuit Boards

August 3, 2008 by 23 Comments


While we hope you enjoyed our How-To: Etch a printed circuit board, toner transfer certainly isn’t the only way to get the job done. [Garrett] from macetech has recently been playing around with using an Epilog laser to etch PCBs. He started by applying a thin even coat of flat black spray paint to the copper board. The laser is used to remove paint in areas that you want the copper removed. Once that’s done, you proceed with etching as usual. He eventually removed the paint mask using acetone. The result has very fine, sharp traces, but most people that have tried this agree that using spray paint is less than ideal.