通用计数器C程序，采用芯片STC11F02E+74HC164，四位共阴数码管，不怕掉电，AC220V交流电检测采用频率采样而快速保存数据到EEPROM，电路简单，成本低，稳定性好。本程序完整，已经批量生产。-Universal counter C program using chip STC11F02E+74HC164, the four common cathode Digital tube, not afraid of power-down, AC220V AC detection usin