这个范例说明如何使用8051， 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

"PASSWORD WRONG"。

当用户按下4ⅹ4小键盘的按钮 B时，可以修改时间。

当用户按下4ⅹ4小键盘的按钮 C时，可以修改密码。*/-This example illustrates how to use the 8051, LCD display and 4 ⅹ 4 small keyboard, create a password lock. PORT 1 to connect to the LCD display data. PORT 3 of P3.3, P3.4 and P3.5, respectively, connected to the control line LCD display. Connected to the PORT 2 of 4 ⅹ 4 small keyboard, you can enter a password. Change Password or time to implement the program, first of all, let LCD display shows time and date.

When the user press the keypad 4 ⅹ 4 button A, you can enter a password. If the password is correct, it will allow the LED flashes P3.6 that lock open. If the password is incorrect when, LCD display will show

"PASSWORD WRONG".

When the user press the keypad 4 ⅹ 4 button B can be modified.

When the user press the keypad 4 ⅹ 4 button C, can modify the password.