http://blog.chinaunix.net/uid-25014876-id-59420.html
http://blog.csdn.net/droidphone/article/details/7445825
http://blog.csdn.net/z2007b/article/details/6385079
http://blog.csdn.net/fudan_abc/article/details/1768232
http://blog.csdn.net/tigerjb/article/details/6011302
GPIO
http://blog.csdn.net/tianxiawuzhei/article/details/7561682