基于AT24C01的多功能密碼控制系統(tǒng)的設(shè)計
The Design Of Multi-functions password control System Based on AT24C01

 
摘    要

隨著科技的日益發(fā)展，電子密碼控制系統(tǒng)已越來越符合人們的要求。本文介紹了基于單片機和串行EEPROM的智能密碼控制系統(tǒng),對系統(tǒng)硬件設(shè)計和軟件實現(xiàn)進行了詳細的描述。該系統(tǒng)采用AT89C51單片機和AT24C01串行EEPROM,通過AT89C51模擬I2C總線和AT24C01通訊,實現(xiàn)密碼控制的功能。
本文從經(jīng)濟實用的角度出發(fā)，采用美國Atmel公司的單片機AT89C51作為主控芯片與數(shù)據(jù)存儲器單元，結(jié)合外圍的矩陣鍵盤輸入、LCD液晶顯示、報警、開鎖等，用C語言編寫主控芯片的控制程序與EEPROM讀寫程序相結(jié)合，設(shè)計了一款可以多次更改密碼，具有報警功能的電子密碼控制系統(tǒng)。這種電路設(shè)計具有防試探按鍵輸入、智能控制上鎖、開鎖、報警、修改密碼等多種功能。密碼長度可變、保密性強、靈活性高。
經(jīng)實驗證明，該密碼控制系統(tǒng)具有設(shè)計方法合理，簡單易行，成本低，安全使用等特點，符合車輛、辦公室用鎖要求，具有推廣價值。

關(guān)鍵詞： 密碼控制；單片機；EEPROM讀寫程序；報警

 
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    錄

1 引言 1
1.1 選題背景 1
1.2 電子密碼控制簡介 1
1.3 電子密碼控制的發(fā)展趨勢 1
1.4 本設(shè)計所要實現(xiàn)的目標 2
2 設(shè)計方案的選擇 3
2.1 方案一：采用數(shù)字電路控制 3
2.2 方案二：采用以單片機為核心的控制方案 3
3 主要元器件介紹及I2C總線說明 4
3.1 主控芯片AT89C51 4
3.1.1 AT89C51性能簡介 4
3.1.2 AT89C51引腳功能說明 5
3.1.3 AT89C51芯片內(nèi)部結(jié)構(gòu) 7
3.2 LCD1602顯示器 8
3.2.1 接口信號說明 8
3.2.2 主要技術(shù)參數(shù) 9
3.2.3 基本操作程序 9
3.3 晶體振蕩器 9
3.4 AT24C01串行EEPROM 10
3.5 I2C總線說明 11
4 系統(tǒng)硬件構(gòu)成 15
4.1 設(shè)計原理 15
4.2 電路總圖構(gòu)成 15
4.3 電源輸入部分 16
4.4 鍵盤輸入部分 16
4.5 復位部分 17
4.6 晶振部分 18
4.7 顯示部分 18
4.8 報警部分 19
5 系統(tǒng)軟件設(shè)計 20
5.1 主程序流程圖 20
5.2 按鍵功能流程圖 21
5.3 密碼設(shè)置流程圖 21
5.4 開鎖流程圖 22
結(jié)    論 24
參考文獻 25
致    謝 26
附錄一：總原理圖 27
附錄二: 程序 29
附錄三: 翻譯 44