51单片机4×4矩阵键盘计算器的代码

以下是一个简单的51单片机4×4矩阵键盘计算器的代码，您可以根据您的需求进行修改和完善。

#include <reg52.h>

#define uchar unsigned char
#define uint unsigned int

uchar keyValue, num1, num2, result;
bit flag = 0, op_flag = 0;

void init() //初始化函数
{
    P1 = 0xf0;
    P2 = 0x00;
    TMOD = 0x01;
    TH0 = 0x3c;
    TL0 = 0xb0;
    TR0 = 1;
    ET0 = 1;
    EA = 1;
}

void delay(uint i) //延时函数
{
    while (i--);
}

void keyScan() interrupt 1 //键盘扫描函数
{
    uchar scanCode;
    P1 = 0xf0;
    scanCode = P1;
    scanCode &= 0xf0;
    if (scanCode != 0xf0)
    {
        delay(1000);
        scanCode = P1;
        scanCode &= 0xf0;
        if (scanCode != 0xf0)
        {
            switch (scanCode)
            {
                case 0x70: keyValue = 1; break;
                case 0xb0: keyValue = 2; break;
                case 0xd0: keyValue = 3; break;
                case 0xe0: keyValue = 4; break;
                case 0x30: keyValue = 5; break;
                case 0x50: keyValue = 6; break;
                case 0x90: keyValue = 7; break;
                case 0xa0: keyValue = 8; break;
                case 0x10: keyValue = 9; break;
                case 0x20: keyValue = 10; break;
                case 0x40: keyValue = 11; break;
                case 0x80: keyValue = 12; break;
                case 0x00: keyValue = 13; break;
            }
            flag = 1;
        }
    }
}

void main() //主函数
{
    init();
    while (1)
    {
        if (flag)
        {
            if (keyValue >= 1 && keyValue <= 9)
            {
                if (!op_flag)
                {
                    num1 = num1 * 10 + keyValue;
                    P2 = keyValue;
                }
                else
                {
                    num2 = num2 * 10 + keyValue;
                    P2 = keyValue;
                }
            }
            else if (keyValue >= 10 && keyValue <= 12)
            {
                op_flag = 1;
                switch (keyValue)
                {
                    case 10: P2 = '+'; break;
                    case 11: P2 = '-'; break;
                    case 12: P2 = '*'; break;
                }
            }
            else if (keyValue == 13)
            {
                switch (P2)
                {
                    case '+': result = num1 + num2; break;
                    case '-': result = num1 - num2; break;
                    case '*': result = num1 * num2; break;
                }
                P2 = result;
                num1 = num2 = 0;
                op_flag = 0;
            }
            flag = 0;
        }
    }
}

注意，这只是一个简单的实现，还有很多地方可以进行优化和改进。例如，可以添加更多的操作符和功能，增加错误处理等。