wire libraryWire协议总线通信中最为重要的一种操作，在每次总线通信之前主机必须首先发送复位信号。如程序1.1所示，产生复位信号时主机首先将总线拉低480~960μs然后释放，由于上拉电阻的存在，此时总线变为高电平。(Wire protocol, the operation of the most important of a kind of bus communication, the host before each bus communication must first send a reset signal. As shown in program 1.1, will generate reset signal host the first bus down 480 ~ 960 mu s and then release, as a result of the existence of pull-up resistors, the bus into a high level.)