单片机密码锁论文.doc

单片机密码锁论文


摘    要

随着科技的日益发展，电子密码控制系统已越来越符合人们的要求。本文介绍了基于单片机和串行EEPROM的智能密码控制系统,对系统硬件设计和软件实现进行了详细的描述。该系统采用AT89C51单片机和AT24C01串行EEPROM,通过AT89C51模拟I2C总线和AT24C01通讯,实现密码控制的功能。
本文从经济实用的角度出发，采用美国Atmel公司的单片机AT89C51作为主控芯片与数据存储器单元，结合外围的矩阵键盘输入、LCD液晶显示、报警、开锁等，用C语言编写主控芯片的控制程序与EEPROM读写程序相结合，设计了一款可以多次更改密码，具有报警功能的电子密码控制系统。这种电路设计具有防试探按键输入、智能控制上锁、开锁、报警、修改密码等多种功能。密码长度可变、保密性强、灵活性高。
经实验证明，该密码控制系统具有设计方法合理，简单易行，成本低，安全使用等特点，符合车辆、办公室用锁要求，具有推广价值。

关键词： 密码控制；单片机；EEPROM读写程序；报警

 
ABSTRACT
As the development of science and technology day by day, the key control system is more in line with the requirements of people. The paper presents a cryptographic smart password control based on MCU and serial EEPROM, describes hardware structure and software design of the system. It adopts AT89C51 and AT24C01, realizes the function of cryptographic smart password control. AT89C51 communicates with AT24C01 by I2C bus to achieve the password control function.
This article from the economical and practical point of view, the use of the United States Atmel Corporation AT89C51 microcontroller as a master chip and the data memory unit, combined with the external matrix keyboard input, LED digital display, alarm, unlock and so on, dominated by the C programming language chip EEPROM of the control procedures and the combination of reading and writing program designed to change a password many times, the police function with the electronic the password control. This circuit design with anti-test button input, intelligent control lock, unlock, alarm, multiple functions, such as Change Password. Password length can be changed, even more secret and flexible than others.
Experiments show that the password control system is characterized by its reasonable designing methods, simple operation, low cost and property of safety and practicality．Besides，the password control can be used in the office and has great potential for commercial development．

Key Words：Password control;  Single-chip;  EEPROM read and write procedures; Alarm

目    录

1 引言 1
1.1 选题背景 1
1.2 电子密码控制简介 1
1.3 电子密码控制的发展趋势 1
1.4 本设计所要实现的目标 2
2 设计方案的选择 3
2.1 方案一：采用数字电路控制 3
2.2 方案二：采用以单片机为核心的控制方案 3
3 主要元器件介绍及I2C总线说明 4
3.1 主控芯片AT89C51 4
3.1.1 AT89C51性能简介 4
3.1.2 AT89C51引脚功能说明 5
3.1.3 AT89C51芯片内部结构 7
3.2 LCD1602显示器 8
3.2.1 接口信号说明 8
3.2.2 主要技术参数 9
3.2.3 基本操作程序 9
3.3 晶体振荡器 9
3.4 AT24C01串行EEPROM 10
3.5 I2C总线说明 11
4 系统硬件构成 15
4.1 设计原理 15
4.2 电路总图构成 15
4.3 电源输入部分 16
4.4 键盘输入部分 16
4.5 复位部分 17
4.6 晶振部分 18
4.7 显示部分 18
4.8 报警部分 19
5 系统软件设计 20
5.1 主程序流程图 20
5.2 按键功能流程图 21
5.3 密码设置流程图 21
5.4 开锁流程图 22
结    论 24
参考文献 25
致    谢 26
附录一：总原理图 27
附录二: 程序 29