FRIC at ivoidwarranties has developed an Arduino addiction. So when his company needed a replacement time clock he wasn’t content to settle for a substandard commercial unit. In the true hacker spirit he designed his own superior time clock system using Arduino and a Stronglink SL018. The SL018 is an RFID reader/writer that interfaces via I2C. Conveniently, it has a ready made Arduino library.
Though initially designed to work in conjunction with a connected PC, he expanded the system to use micro SD card logging and ethernet connectivity, along with an DS3232 RTC in order to make the project a standalone unit.