reversing washing machine payment cards:
To use the washing machines in my apartment complex you need to pay using a rechargeable contact card.
I was curious to find out how it works. It turns out it's an I²C EEPROM in a card.
By recording the communication between the card and the machine I figured out where and how the credit value is stored.
Now I can read and write the value on cards using a Raspberry Pi or simple micro-controller, but also program my own cards to work with the machines.
recipe:
- OMNIKEY CardMan 5321 card reader
- pcsc_scan smart card utility for linux (look for the pcsc-tools package for your distribution)
- workbench smart card utility for Windows
- ID-1 card slot
- 150x70x0.8 mm copper clad
- Arduino Nano
- I²C EEPROM card
Published: 2015-05-07 by King Kévin