关于#51单片机#的问题，请各位专家解答！(语言-c语言)

Question

c51单片机想要做一个重置密码键k13，用到AT24C02来存储密码 应该怎么写这个代码呢？求解

#include<reg51.h>
#include<string.h>
sbit lcd_RS=P2^0;
sbit lcd_RW=P2^1;
sbit lcd_E=P2^2;
sbit jidianqi=P2^7;
sbit buzzer = P3^0;
char key[]={0,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x30};  //键值
char key2[]="Correct";
char key3[]="Error";
char table[]="password";
char table1[]="input:";
char passwordInput[5]; 

delay(unsigned int x)          
{       
    unsigned int i;
    for(x=0;x<100;x++)
        for(i=0;i<x;i++);
}
wuyuan()
{ int k;
  
  for(k=0;k<20;k++)
  {      buzzer=1;
     delay(39999);
     buzzer=0;
     delay(39999);
   }
}

write_com(unsigned char com )     
{
    while(lcd_busy());
    lcd_RS=0;
    lcd_RW=0;
    delay(200);
    P0=com;
    delay(200);
    lcd_E=1;
    delay(200);
    lcd_E=0;
}
write_dat(unsigned char dat ) 
{
    while(lcd_busy());
    lcd_RS=1;
    lcd_RW=0;
    P0=dat;
    delay(200); 
    lcd_E=1;
    delay(200);
    lcd_E=0;
}
void write_password_char()
{write_dat(42);
}
lcd_busy()
{ 
    unsigned char temp;
    lcd_RS=0;
    lcd_RW=1;
    delay(20);
    P0=0xff;
    delay(20);
    lcd_E=1;
    delay(20);
    temp=P0;
    delay(20);
    lcd_E=0;
    return(temp&0x80);
}
init()                       
{ 
    write_com(0x01);
    write_com(0x38);
    write_com(0x0c);
    write_com(0x06);
} 
juxingjianpan()                      
{ 
    unsigned char KeyNumber,x,y;
    P1=0x0f;              
    x=P1;
    P1=0xf0;
    y=P1;
    switch(x+y)
    { 
        case 0xee:      KeyNumber=1;break;
        case 0xde:      KeyNumber=2;break;
        case 0xbe:      KeyNumber=3;break;
        case 0x7e:      KeyNumber=4;break;
        case 0xed:      KeyNumber=5;break;
        case 0xdd:      KeyNumber=6;break;
        case 0xbd:      KeyNumber=7;break;
        case 0x7d:      KeyNumber=8;break;
        case 0xeb:      KeyNumber=9;break;         
        case 0xdb:      KeyNumber=10;break;
        case 0xbb:        KeyNumber=11;break;
        case 0x7b:        KeyNumber=12;break;
        case 0xe7:        KeyNumber=12;break;
    }
    return KeyNumber;
}                    
void main() {static unsigned char position = 0,x = 0,y; 
unsigned int i, KeyNum, passwordLen = 0;
init();
write_com(0x80);
for(i = 0; i < 8; i++) {
write_dat(table[i]);
}
write_com(0xc0);
for(i = 0; i < 6; i++) {
write_dat(table1[i]);
}
 // 将静态变量定义移到while循环外部
while(1) {

write_com(0xc6 + position);
KeyNum = juxingjianpan();
if(KeyNum) {
if(KeyNum <= 10) {
if(x <= 3) {
write_password_char();
delay(5);
passwordInput[passwordLen++] = key[KeyNum];
position++;
}
x++;
}  if(KeyNum == 11) { // 确认键
if (strcmp(passwordInput, "1234") == 0) {
write_com(0x01);
delay(20);
write_com(0x86);
jidianqi=0;
for(y = 0; y < 7; y++) {
write_dat(key2[y]);
delay(5);
}
} else {
write_com(0x01);
delay(20);
write_com(0x86);
wuyuan();
for(y = 0; y < 5; y++) {
write_dat(key3[y]);
delay(5);
}
}
memset(passwordInput, 0, sizeof(passwordInput));
passwordLen = 0;
x = 0;
position = 0;
} else if (KeyNum == 12) {
memset(passwordInput, 0, sizeof(passwordInput));
passwordLen = 0;
x = 0;
position = 0;
buzzer=1;
delay(20);
buzzer=0;
delay(20);
jidianqi=1;
write_com(0x01);
write_com(0x80);
for(i = 0; i < 8; i++) {
write_dat(table[i]);
}
write_com(0xc0);
for(i = 0; i < 6; i++) {
write_dat(table1[i]);
}
}
}
}
}

Answer 1

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为了实现基于51单片机的重置密码功能，您需要结合现有的代码和AT24C02 EEPROM芯片进行扩展。在您的程序中，首先需要初始化I2C通信以与AT24C02通信，并添加读取、写入和擦除AT24C02存储单元的函数。

以下是一个简化的示例，展示了如何将密码存入AT24C02以及如何从EEPROM读取密码进行验证：

#include<reg51.h>
#include<string.h>
#include "i2c.h" // 假设你有一个包含I2C驱动的头文件

// I2C初始化函数（请根据实际硬件配置实现）
void init_I2C() {
    // 初始化I2C接口，例如SCL和SDA引脚方向和工作模式
}

// 向AT24C02写入一个字节数据到指定地址
void write_to_AT24C02(unsigned int addr, unsigned char data) {
    start_I2C(); // 发送I2C起始信号
    write_I2C(AT24C02_ADDR); // 写入设备地址
    write_I2C(addr); // 写入EEPROM内部地址
    write_I2C(data); // 写入数据
    stop_I2C(); // 发送停止信号
}

// 从AT24C02读取一个字节数据
unsigned char read_from_AT24C02(unsigned int addr) {
    unsigned char data;
    start_I2C();
    write_I2C(AT24C02_ADDR | 0x01); // 读取设备地址
    write_I2C(addr); // 写入EEPROM内部地址
    restart_I2C(); // 发送重启信号
    write_I2C(AT24C02_ADDR | 0x01); // 再次发送读取设备地址
    data = read_I2C(); // 读取数据
    stop_I2C();
    return data;
}

// 存储密码到AT24C02
void store_password(char* password, unsigned int addr) {
    for (int i = 0; i < PASSWORD_LENGTH && password[i]; ++i) {
        write_to_AT24C02(addr + i, password[i]);
    }
}

// 从AT24C02读取密码并验证
int verify_password(char* input, unsigned int addr) {
    char stored_password[PASSWORD_LENGTH + 1];
    memset(stored_password, 0, sizeof(stored_password));
    
    for (int i = 0; i < PASSWORD_LENGTH; ++i) {
        stored_password[i] = read_from_AT24C02(addr + i);
    }

    if (strcmp(input, stored_password) == 0) {
        return 1; // 验证成功
    } else {
        return 0; // 验证失败
    }
}

// ... （保留原有的按键扫描和LCD显示相关代码）

// 在main函数或其他适当位置调用存储和验证密码函数
int main(void) {
    // 初始化部分...
    
    // 假设已获取输入的密码
    char input_password[6];
    // ...（获取密码的代码）

    // 存储密码到AT24C02
    store_password("1234", PASSWORD_START_ADDR);

    // 验证密码
    if (verify_password(input_password, PASSWORD_START_ADDR)) {
        // 密码正确操作
    } else {
        // 密码错误操作
    }

    // ...（剩余的主循环和其他处理）
}

请根据你的实际硬件连接和I2C驱动库替换上述init_I2C()、start_I2C()、stop_I2C()、restart_I2C()、write_I2C() 和 read_I2C() 函数内容。同时，请确保PASSWORD_LENGTH和PASSWORD_START_ADDR分别设置为你的密码长度和EEPROM中存储密码的起始地址。