This article designed has hit the bell system's hardware circuit and the software routine automatically. Automatically hits the bell system take monolithic integrated circuit AT89C51 as the microprocessor, DS12887 is the clock chip, 8279 for the keyboard demonstration connection chip, realized has hit the bell automatically, the system may according to need to hit bell's time through the keyboard adjustment, through 6 nixietube demonstration current time. In the article has given the hardware circuit diagram and the software routine, and has given the flow chart to the subprogram design. Hits the bell system circuit to be simple automatically, the function is complete.
key word: Hits the bell system automatically; Monolithic integrated circuit AT89C51; DS12887; 8279
