说明：  利用矩阵键盘和1602实现简易的密码锁功能，并且可以将密码保存在24c02中，达到单片机掉电之后密码不丢失的功能。通过按键连续输入错误三次，按键将被锁定，不能再进行输入。连续输入正确两次进入更改密码选项。初始密码为000000，如果忘记密码时可以输入131420初始化密码。
(Using the matrix keyboard and 1602 to realize the simple password lock function, and can save the password in the 24C02, to achieve the function that the password will not be lost after the single chip computer power off. By keystroke continuous input error three times, the key will be locked, and can no longer input. Enter the correct two times continuously and enter the password change option. The initial password is 000000. If you forget the password, you can enter the 131420 initialization password.)