MFRC522

https://www.raspberrypi.org/documentation/hardware/raspberrypi/spi/README.md
https://github.com/mxgxw/MFRC522-python
http://nfc-tools.org/index.php?title=Libnfc
https://www.nxp.com/cn/

http://blog.csdn.net/a827415225/article/details/51898897
http://www.cnblogs.com/lubiao/p/4716965.html
http://www.cnblogs.com/lubiao/p/4716965.html

http://www.alldatasheet.com/datasheet-pdf/pdf/227839/NXP/MFRC522.html