单片机编写DS1302驱动程序，数码管显示实时时间 。时钟设置说明：8键"为时钟设置、时分切换、保存 "0键"为加 "4键"为减。-The MCU write the DS1302 driver, digital tube displays real time. Clock settings: 8 keys to set the clock, time-division switch, save the "key" plus "key" for the reduction.