设计一种单片机控制的密码锁，具有按键有效提示、解码有效提示、控制开锁电平、控制报警、密码修改等功能。密码锁的控制程序由主程序及延时子程序、、键盘输入子程序、修改密码子程序、比较密码子程序、显示等子程序组成。密码锁在输入密码正确的条件下输出开锁电平，控制电控锁开启，同时显示OPEN字样。当输入密码错误时，错误指示灯亮，同时显示CLOSE字样。当三次误码输入时，产生报警电平报警。还可以实现对密码的修改，修改密码时，修改时指示灯亮，修改完成后，指示灯灭。要求选用AT89C51单片机和适当的电子元器件完成相应的功能并用LED显示电子锁的不同状态。-Design a single-chip control lock with key tips, effectively decoding effective tips, control the unlocking level, alarm control, password changes and other functions. Lock control procedures by the main program and delay subroutine, the keyboard input routines, modify the password subroutine, the comparison Password subroutine, display subprograms. Locks unlocking level in the correct password is input, output, control electronically controlled lock open, OPEN words. When the wrong password is entered, the error indicator light, display CLOSE words. When three error input, an alarm level alarm. You can also password changes, change the password, modify light, the modification is complete, the indicator light turns off. Selection requirements AT89C51 microcontroller and proper completion of the electronic components of the corresponding function and the different states of the electronic lock with LED display.