树莓派安装libnfc

https://www.arduino.cn/thread-5960-1-1.html

https://www.cnblogs.com/k1two2/p/5751589.html

https://www.rabbittu.com/raspi-pn532/

http://www.jamesrobertson.eu/blog/2016/feb/08/using-a-pn532-nfc-rfid-reader-with-the-raspberry-pi.html


改SPI速度导280000