类似电脑键盘组合按键触发的功能。利用51单片机实现。有两个独立按键，当把两个独立按键都按下后，蜂鸣器发出“滴”的一声后就停。直到松开任一个按键后，才能重新进行下一次的组合按键触发。-Similar to the function of the keyboard combination of keys. The use of 51 single chip microcomputer. There are two independent buttons, when the two independent buttons are pressed, the buzzer issued a drop of sound after the stop. Until after the release of any key, the next combination of keys can be re trigger.