基于51单片机的多功能数字钟。时间，年月日，多组闹钟，议程。且外接24C04的EEPROM后可保存设置。蜂鸣器由I/O口接三极管放大后驱动。-51 microcontroller-based multifunctional digital clock. Time, date, multiple alarm clocks, and the agenda. 24 C04 and external EEPROM kept after setting up. The buzzer sounded by the I / O access triode mouth amplified drive.