利用stc89c52,at24c02以及按键和lcd1602做的电子密码锁，可以自己修改密码并有错误提示。用了很长时间做出来的。-Use stc89c52, at24c02 and the buttons and lcd1602 do electronic code lock, can modify their own password and an error message. Took a long time to do it.