DIY Credit Card Reader
Using a card reader that was purchased for $1.50 Mondo Technology used a PIC12F675 to bring it to life. “The unit provides the magnetic head on a spring mechanism along with low level head signal amplifiers and data slicers. Three signal lines comming from the unit provide card presence, clock, and data. When actively reading a card, it draws about 50ma of current at 5 volts.”