LCD显示器和4ⅹ4的小键盘，制作一个密码锁。PORT 1 连接到LCD显示器的数据线。PORT 3 的P3.3,P3.4和P3.5分别连接到LCD显示器的控制线。PORT 2连接到4ⅹ4的小键盘，可以输入密码。执行修改密码或是时间的程序时，首先让LCD显示器显示出时间和日期。

当用户按下4ⅹ4小键盘的按钮 A 时，可以输入密码。如果密码正确时，就会让 P3.6的 LED 闪烁，表示打开锁。如果密码不正确时，LCD显示器就会显示出-LCD display and 4 ⅹ 4 small keyboard, make a lock. PORT 1 to connect to the LCD monitor cable. PORT 3 of P3.3, P3.4 and P3.5 are connected to the control line LCD display. PORT 2 connected to the 4 ⅹ 4 small keyboard, you can enter the password. Implementation of the revised code, or time-consuming procedures, the first LCD monitors to display the time and date. When the user presses the 4 ⅹ 4 A small button on the keyboard, you can enter the password. If the password is correct, they will let P3.6 the LED blinking, open the lock. If the password is not correct, LCD display will show