1) 4×4行列式键盘识别

2)8位数码显示，初始化时，显示“P　　　”，接着输入最大6位数的密码，当密码输入完后，按下确认键，进行密码比较，然后给出相应的信息。在输入密码过程中，显示器只显示“8.”。当数字输入超过6个时，给出报警信息。在密码输入过程中，若输入错误，可以利用“DEL”键删除刚才输入的错误的数字。

-1) 4 × 4 determinant recognition keyboard 2) 8-bit digital display, initialization, the display " P" , then enter the password for the largest 6-digit, when the password after pressing the confirm key, password comparison, and then given the appropriate information. Enter a password in the process, the display only shows " 8." . When the digital input more than six hours, give the police information. Password input in the process, if the input error, we can use " DEL"　key to delete just the number of input errors.