Decode what's hidden on your credit cards, or use it for an access system - this mag-stripe card reader can decode the two most common tracks used, #1 and #2! We like this small and easy to use mag-stripe reader for being so microcontroller-friendly. Instead of a USB port, it has a PS/2 interface and acts like a 'keyboard'. In fact, its designed to be a 'pass through'/'keyboard wedge' device for point-of-sale terminals. What's nice about PS/2 is that it uses a single connector for power and data, and uses two data pins. When a card is swiped, the raw data is decoded, parity-checked and spit out as if they were typed on a keyboard.
There is one magnetic head but you can swipe in either direction and will emit data in the right order.
Nearly all microcontrollers have existing PS/2 keyboard examples that would work fine with this swiper. For Ardiuno users, we tried out PJRC's PS2_Keyboard library with great success - just check the 'simple text' example for which pins you can connect to on your 'duino (on an Uno we used digital pins 2 and 3). We suggest our PS/2 adapter cable to make the wiring easy. Swipe any magnetic card and you'll see the data appear in the serial terminal!
This reader will read and decode the first two tracks of standard magnetic-stripe cards. It cannot write to cards, and cannot be modified to write to cards. We also have a three-track reader which is more expensive but reads all the tracks. Wikipedia has a great article on magnetic stripe cards which will help you determine if you need a three-track reader or if a two-track reader is good enough.