用4×4组成0－9数字键及确认键。

用8位数码管组成显示电路提示信息，当输入密码时,

只显示“8.”，当密码位数输入完毕按下确认键时，对输入的密码与设定的密码进行比

较，若密码正确，则门开，此处用LED发光二极管亮一秒钟做为提示，同时发出“叮”

声；若密码不正确，禁止按键输入3秒，同时发出“嘀、嘀”报警声；若在3秒之内仍有

按键按下，则禁止按键输入3秒被重新禁止。-With 44 0-9 number keys and the Enter key. The composition of the eight digital tube display circuit message, enter a password, the only " 8." , Press the Enter key when the password digit input is completed, enter the password and set the password to compare, if the password is correct , the door opened, here LED light-emitting diode light for a second as prompted, also issued a " ding"　sound　if the password is incorrect, Disable keyboard 3 seconds, also issued a " beep, beep"　alarm sound　3 seconds within the still button is pressed, the three seconds re prohibit Disable keyboard.