Eelcor over at the 430h forum shared his Energia library for the Milfare RC522 RFID card:
I wanted to share my results with the MF RC522 RFID reader. I found an article from Grant Gibson where he used a cheap reader from eBay to read Mifare cards.
The command set and technical aspects of the MFRC522 chip can be found in the datasheet
I have ported the example to Energia. Very simple by removing all Chinese comments and replacing uchar with unsigned chars.
After these changes it works like a charm.