基于51单片机利用矩阵按键实现密码锁 c语言

以下是基于51单片机利用矩阵按键实现密码锁的C语言代码，你可以参考一下：

#include <reg52.h>
#include <intrins.h>

#define uchar unsigned char
#define uint unsigned int

sbit RS = P2^6;  // LCD1602液晶显示屏接口定义
sbit RW = P2^5;
sbit EN = P2^7;
sbit KEY_IN_1 = P1^0;  // 矩阵按键接口定义
sbit KEY_IN_2 = P1^1;
sbit KEY_IN_3 = P1^2;
sbit KEY_IN_4 = P1^3;
sbit KEY_OUT_1 = P1^4;
sbit KEY_OUT_2 = P1^5;
sbit KEY_OUT_3 = P1^6;
sbit KEY_OUT_4 = P1^7;

uchar password[4] = {1, 2, 3, 4};  // 设置初始密码
uchar keyvalue = 0;
uchar keyflag = 0;
uchar input_pwd[4] = {0, 0, 0, 0};
uchar input_count = 0;
uchar error_count = 0;

void init_lcd1602()  // LCD1602液晶显示屏初始化
{
    delay(20);
    write_com(0x38);
    delay(5);
    write_com(0x38);
    delay(5);
    write_com(0x38);
    delay(5);
    write_com(0x38);
    delay(5);
    write_com(0x08);
    delay(5);
    write_com(0x01);
    delay(5);
    write_com(0x06);
    delay(5);
    write_com(0x0c);
    delay(5);
}

void delay(uint x)  // 延时函数
{
    uint i, j;
    for(i = x; i > 0; i--)
        for(j = 110; j > 0; j--);
}

void write_com(uchar com)  // 写指令函数
{
    RS = 0;
    RW = 0;
    P0 = com;
    EN = 1;
    _nop_();
    EN = 0;
}

void write_data(uchar dat)  // 写数据函数
{
    RS = 1;
    RW = 0;
    P0 = dat;
    EN = 1;
    _nop_();
    EN = 0;
}

void keyscan()  // 矩阵按键扫描函数
{
    KEY_OUT_1 = 0;
    if(KEY_IN_1 == 0)
    {
        keyvalue = 1;
        keyflag = 1;
    }
    if(KEY_IN_2 == 0)
    {
        keyvalue = 2;
        keyflag = 1;
    }
    if(KEY_IN_3 == 0)
    {
        keyvalue = 3;
        keyflag = 1;
    }
    if(KEY_IN_4 == 0)
    {
        keyvalue = 4;
        keyflag = 1;
    }
    KEY_OUT_1 = 1;

    KEY_OUT_2 = 0;
    if(KEY_IN_1 == 0)
    {
        keyvalue = 5;
        keyflag = 1;
    }
    if(KEY_IN_2 == 0)
    {
        keyvalue = 6;
        keyflag = 1;
    }
    if(KEY_IN_3 == 0)
    {
        keyvalue = 7;
        keyflag = 1;
    }
    if(KEY_IN_4 == 0)
    {
        keyvalue = 8;
        keyflag = 1;
    }
    KEY_OUT_2 = 1;

    KEY_OUT_3 = 0;
    if(KEY_IN_1 == 0)
    {
        keyvalue = 9;
        keyflag = 1;
    }
    if(KEY_IN_2 == 0)
    {
        keyvalue = 10;
        keyflag = 1;
    }
    if(KEY_IN_3 == 0)
    {
        keyvalue = 11;
        keyflag = 1;
    }
    if(KEY_IN_4 == 0)
    {
        keyvalue = 12;
        keyflag = 1;
    }
    KEY_OUT_3 = 1;

    KEY_OUT_4 = 0;
    if(KEY_IN_1 == 0)
    {
        keyvalue = 13;
        keyflag = 1;
    }
    if(KEY_IN_2 == 0)
    {
        keyvalue = 14;
        keyflag = 1;
    }
    if(KEY_IN_3 == 0)
    {
        keyvalue = 15;
        keyflag = 1;
    }
    if(KEY_IN_4 == 0)
    {
        keyvalue = 16;
        keyflag = 1;
    }
    KEY_OUT_4 = 1;
}

void display_pwd()  // 显示密码函数
{
    uchar i;
    write_com(0x80);
    write_data('I');
    write_data('n');
    write_data('p');
    write_data('u');
    write_data('t');
    write_data(':');
    for(i = 0; i < 4; i++)
    {
        write_data(input_pwd[i] + '0');
    }
}

void main()
{
    init_lcd1602();  // 初始化LCD1602液晶显示屏

    while(1)
    {
        keyscan();  // 扫描矩阵按键

        if(keyflag == 1 && input_count < 4)  // 如果有按键按下且密码未输入完整
        {
            input_pwd[input_count++] = keyvalue;  // 记录输入的密码
            display_pwd();  // 显示输入的密码
            keyflag = 0;
        }

        if(input_count == 4)  // 如果密码输入完整
        {
            if(input_pwd[0] == password[0] && input_pwd[1] == password[1] && input_pwd[2] == password[2] && input_pwd[3] == password[3])  // 如果密码正确，开锁
            {
                write_com(0xc0);
                write_data('W');
                write_data('e');
                write_data('l');
                write_data('c');
                write_data('o');
                write_data('m');
                write_data('e');
                delay(1000);
                input_count = 0;
                error_count = 0;
                write_com(0x01);
            }
            else  // 如果密码错误
            {
                error_count++;  // 记录错误次数

                if(error_count >= 3)  // 如果错误次数超过3次，锁定系统
                {
                    write_com(0x01);
                    write_com(0x80);
                    write_data('S');
                    write_data('y');
                    write_data('s');
                    write_data('t');
                    write_data('e');
                    write_data('m');
                    write_data(' ');
                    write_data('L');
                    write_data('o');
                    write_data('c');
                    write_data('k');
                    delay(5000);
                    error_count = 0;
                    write_com(0x01);
                }
                else  // 如果错误次数未超过3次，显示错误信息
                {
                    write_com(0xc0);
                    write_data('E');
                    write_data('r');
                    write_data('r');
                    write_data('o');
                    write_data('r');
                    write_data('!');
                    delay(1000);
                    input_count = 0;
                    write_com(0x01);
                }
            }
        }
    }
}

以上代码仅供参考，实际应用中可能还需要根据具体情况进行修改和完善。