IIC

代码说明：

  使用数码管和AT24C02实现： 1、数码管从0显示到99，溢出后从0循环显示，时间间隔为一秒。 2、显示到某个数时突然关闭电源，AT24C02将保存当前的数字。 3、重新启动后数码管会接着上次的数继续显示(Using digital tube and AT24C02 implementation: 1, the digital tube displays from 0 to 99. After overflow, it displays from 0 cycles, with a time interval of one second. 2, display a number of time to turn off the power suddenly, AT24C02 will save the current number. 3, after reboot, the number will continue to display.)