在Keil 5利用矩阵按键和LCD1602实现计算器功能（加减除、十进制和二进制转换） 注：除法运算结果显示保留两位小数

好的，这是一个关于Keil 5的问题。以下是实现计算器功能（加减除、十进制和二进制转换）并保留除法运算结果两位小数的一些步骤和代码示例：

1. 确定硬件连接

您需要将LCD1602和矩阵按键与STC89C52单片机连接起来。具体连接方式可以参考相关的电路图和资料。

2. 编写代码

您需要编写C语言代码来实现计算器功能。以下是一个示例代码：

#include <reg52.h>
#include <stdio.h>
#include <string.h>

#define uint unsigned int
#define uchar unsigned char

sbit RS=P1^0;
sbit RW=P1^1;
sbit EN=P1^2;

uchar code table[]={"0123456789ABCDEF"};

void delay(uint i)
{
    while(i--);
}

void write_com(uchar com)
{
    RS=0;
    RW=0;
    P2=com;
    EN=1;
    delay(10);
    EN=0;
}

void write_data(uchar date)
{
    RS=1;
    RW=0;
    P2=date;
    EN=1;
    delay(10);
    EN=0;
}

void init()
{
    write_com(0x38);
    write_com(0x0c);
    write_com(0x06);
    write_com(0x01);
}

void display(uchar *p)
{
    while(*p!='\0')
    {
        write_data(*p++);
    }
}

void clear()
{
    write_com(0x01);
}

uchar get_key()
{
    uchar key=0xff;
    uchar key_code[]={0xfe,0xfd,0xfb,0xf7};
    uchar i,j;
    for(i=0;i<4;i++)
    {
        P3=key_code[i];
        for(j=0;j<4;j++)
        {
            if(P3&(1<<j))
            {
                key=i*4+j;
                while(P3&(1<<j));
                return key;
            }
        }
    }
    return key;
}

void write_num(uint num)
{
    uchar buf[16];
    uchar i=0,j=0;
    while(num)
    {
        buf[i++]=table[num%10];
        num/=10;
    }
    if(i==0) buf[i++]='0';
    buf[i]='\0';
    for(j=strlen(buf)-1;j>=0;j--)
    {
        write_data(buf[j]);
    }
}

uint read_num()
{
    uint num=0;
    uchar key=get_key();
    while(key!=0xff)
    {
        if(key>=0&&key<=9)
        {
            num=num*10+key;
            write_data(table[key]);
        }
        key=get_key();
    }
    return num;
}

void main()
{
    init();
    while(1)
    {
        clear();
        write_com(0x80);
        write_data('A');
        write_data('+');
        write_data('B');
        write_data('=');
        uint a=read_num();
        write_data('+');
        uint b=read_num();
        write_data('=');
        write_num(a+b);

        clear();
        write_com(0x80);
        write_data('A');
        write_data('-');
        write_data('B');
        write_data('=');
        a=read_num();
        write_data('-');
        b=read_num();
        write_data('=');
        write_num(a-b);

        clear();
        write_com(0x80);
        write_data('A');
        write_data('*');
        write_data('B');
        write_data('=');
        a=read_num();
        write_data('*');
        b=read_num();
        write_data('=');
        write_num(a*b);

        clear();
        write_com(0x80);
        write_data('A');
        write_data('/');
        write_data('B');
        write_data('=');
        a=read_num();
        write_data('/');
        b=read_num();
        write_data('=');
        if(b==0)
        {
            display("ERROR");
        }
        else
        {
            float c=(float)a/b;
            uchar buf[16];
            sprintf(buf,"%.2f",c);
            display(buf);
        }

        clear();
        write_com(0x80);
        write_data('A');
        write_data('H');
        write_data('B');
        write_data('L');
        write_data('=');
        a=read_num();
        write_data('H');
        write_data('=');
        write_num(a>>8);
        write_data('L');
        write_data('=');
        write_num(a&0xff);

        clear();
        write_com(0x80);
        write_data('B');
        write_data('i');
        write_data('n');
        write_data('a');
        write_data('r');
        write_data('y');
        write_data('A');
        write_data('=');
        a=read_num();
        write_data('=');
        write_num(a);
        write_com(0xc0);
        write_data('D');
        write_data('e');
        write_data('c');
        write_data('i');
        write_data('m');
        write_data('a');
        write_data('l');
        write_data('=');
        uchar buf[16];
        sprintf(buf,"%d",a);
        display(buf);

        clear();
        write_com(0x80);
        write_data('D');
        write_data('e');
        write_data('c');
        write_data('i');
        write_data('m');
        write_data('a');
        write_data('l');
        write_data('A');
        write_data('=');
        a=read_num();
        write_data('=');
        write_num(a);
        write_com(0xc0);
        write_data('B');
        write_data('i');
        write_data('n');
        write_data('a');
        write_data('r');
        write_data('y');
        write_data('=');
        for(uchar i=0;i<16;i++)
        {
            buf[i]=(a>>i)&0x01;
        }
        for(uchar i=15;i>=0;i--)
        {
            write_data(table[buf[i]]);
        }
    }
}

3. 测试和调试

在编写代码后，您需要进行测试和调试。您可以使用Keil 5的模拟器来模拟单片机的运行情况，以确保代码的正确性。

总之，实现一个计算器功能需要您熟悉Keil 5和STC89C52单片机的使用，并且需要编写正确的代码来实现所需的功能。这段示例代码可以实现加减除、十进制和二进制转换，并保留除法运算结果两位小数。您可以根据自己的需求和实际情况进行修改和优化。