Platform: Arduino
References:
- magstripelib
- Magnetic Card Reader (TTL) with Arduino
- Magnetic Card Reader (TTL) with Arduino Part II
Code to allow an Arduino to read from more than one magnetic card reader. The code was modified from the magstripelib Arduino library. If you only need to read from one card reader and the data line of your reader is free from noise then you should consider using the magstripelib library instead of the code presented here.
In addition to the code, there are some photos and Inkscape files for laser cutting a board to mount two Tokin MCS-131P-3 magnetic card readers and an Adafruit Perma-Proto Half-sized Breadboard PCB.
When selecting the data pin, keep in mind which pins may be used as interrupts. The Uno, Nano, Mini, & other 328-based boards have only two pins available with interrupts. Other boards have more but many have limited pins available. Check the Arduino reference page at https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/ for details.
For more information regarding this project, please visit the two part blog post listing in the references above.