串口基础知识
http://www.cnblogs.com/menlsh/archive/2013/01/28/2880580.html
DTU知识
http://blog.csdn.net/xutonghuang1986/article/details/16845491
http://blog.csdn.net/bichenggui/article/details/7889638
Windows串口编程
原文：http://www.cnblogs.com/rjjs/p/5667102.html
