大神，求51单片机做简易计算器的那个c语言程序

以下是我编的简易计算器程序，基本成功
//4*4键盘检测程序,按下键后相应的代码显示在液晶屏上
//显示5位后，第6次显示操作符号
//再显示下一个数
// 键值与功能对应表
//键值 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
//功能 0 1 2 3 4 5 6 7 8 9 + - × ÷ = 清零
#include
sbit beep=P2^3;
sbit lcden=P3^4;
sbit rs=P3^5;
sbit rw=P3^6;

#define uint unsigned int
#define ulint unsigned long int
#define uchar unsigned char
#define lcddata P0

ulint bb,dd,ee,ff;
uchar d,flag1;
uchar fd1,fd2;
uchar b1=16,b2=16,b3=16,b4=16,b5=16;
uchar d1=16,d2=16,d3=16,d4=16,d5=16;
uchar f1=16,f2=16,f3=16,f4=16,f5=16,f6=16,f7=16,f8=16,f9=16,f10=16;
uchar key,keyval,c,temp;

void Delay1ms(uint i) //1ms延时程序
{
uint j;
for(;i>0;i--)
{
for(j=0;j<125;j++)
{;}
}
}

void write_com(uchar com)
{
lcddata=com;
rs=0;
rw = 0;
lcden=0;
Delay1ms(10);
lcden=1;
Delay1ms(10);
lcden=0;
}
void write_date(uchar date)
{
lcddata=date;
rs=1;
rw=0;
lcden=0;
Delay1ms(10);
lcden=1;
Delay1ms(10);
lcden=0;
}

void init2()
{
rw=0;
write_com(0x38);
Delay1ms(10);
write_com(0x0f);
Delay1ms(10);
write_com(0x06);
Delay1ms(10);
write_com(0x01);
Delay1ms(10);
}

void display1(uchar A1,uchar A2,uchar A3,uchar A4,uchar A5) //第1个数显示程序
{
init2();
write_com(0x80);//第1行,第1字
Delay1ms(10);
write_date(0x30+A1);
Delay1ms(10);
write_date(0x30+A2);
Delay1ms(10);
write_date(0x30+A3);
Delay1ms(10);
write_date(0x30+A4);
Delay1ms(10);
write_date(0x30+A5);
Delay1ms(10);
}
void display2(uchar A1,uchar A2,uchar A3,uchar A4,uchar A5) //第2个数显示程序
{
write_com(0x88);//第1行,第1字
Delay1ms(10);
write_date(0x30+A1);
Delay1ms(10);
write_date(0x30+A2);
Delay1ms(10);
write_date(0x30+A3);
Delay1ms(10);
write_date(0x30+A4);
Delay1ms(10);
write_date(0x30+A5);
Delay1ms(10);
}

void display3(uchar a) //操作符号显示程序
{
write_com(0x86);//第1行,第1字
Delay1ms(10);
switch(a)
{
case 10:
write_date('+');
Delay1ms(10);
case 11:
write_date('-');
Delay1ms(10);
case 12:
write_date('x');
Delay1ms(10);
case 13:
write_date('/');
Delay1ms(10);
}
}

void display4(uchar A1,uchar A2,uchar A3,uchar A4,uchar A5,uchar A6,uchar A7,uchar A8,uchar A9,uchar A10,uchar A11,uchar A12) //结果显示程序
{
write_com(0x80+0x40);//第2行,第1字
Delay1ms(10);
if (flag1==0)
{
write_date('-');
}
else write_date('+');
Delay1ms(10);
write_date(0x30+A1);
Delay1ms(10);
write_date(0x30+A2);
Delay1ms(10);
write_date(0x30+A3);
Delay1ms(10);
write_date(0x30+A4);
Delay1ms(10);
write_date(0x30+A5);
Delay1ms(10);
write_date(0x30+A6);
Delay1ms(10);
write_date(0x30+A7);
Delay1ms(10);
write_date(0x30+A8);
Delay1ms(10);
write_date(0x30+A9);
Delay1ms(10);
write_date(0x30+A10);
Delay1ms(10);
write_date('.');
Delay1ms(10);
write_date(0x30+A11);
Delay1ms(10);
write_date(0x30+A12);
Delay1ms(10);
}

uchar keyscan()
{
key=16;
P3=0xef;//P3.7输出1个低电平
temp=P3; //读取
temp=temp&0x0f;//屏蔽高4位
if(temp!=0x0f)
{
Delay1ms(10);
if(temp!=0x0f)
{
temp=P3;
switch(temp)
{
case 0xee:
key=0;
break;

case 0xed:
key=4;
break;

case 0xeb:
key=8;
break;

case 0xe7:
key=12;
break;
}
while(temp!=0x0f)
{
temp=P3;
temp=temp&0x0f;
beep=0;
}
beep=1;

}
}

P3=0xdf;
temp=P3;
temp=temp&0x0f;
if(temp!=0x0f)
{
Delay1ms(10);
if(temp!=0x0f)
{
temp=P3;
switch(temp)
{
case 0xde:
key=1;
break;

case 0xdd:
key=5;
break;

case 0xdb:
key=9;
break;

case 0xd7:
key=13;
break;
}
while(temp!=0x0f)
{
temp=P3;
temp=temp&0x0f;
beep=0;
}
beep=1;

}
}

P3=0xbf;
temp=P3;
temp=temp&0x0f;
if(temp!=0x0f)
{
Delay1ms(10);
if(temp!=0x0f)
{
temp=P3;
switch(temp)
{
case 0xbe:
key=2;
break;

case 0xbd:
key=6;
break;

case 0xbb:
key=10;
break;

case 0xb7:
key=14;
break;
}
while(temp!=0x0f)
{
temp=P3;
temp=temp&0x0f;
beep=0;
}
beep=1;

}
}

P3=0x7f;
temp=P3;
temp=temp&0x0f;
if(temp!=0x0f)
{
Delay1ms(10);
if(temp!=0x0f)
{
temp=P3;
switch(temp)
{
case 0x7e:
key=3;
break;

case 0x7d:
key=7;
break;

case 0x7b:
key=11;
break;

case 0x77:
key=15;
break;
}
while(temp!=0x0f)
{
temp=P3;
temp=temp&0x0f;
beep=0;
}
beep=1;

}
}
return(key);
}

void main()
{ while(1)
{
c=1;
while(c<6)//输入第1个5 位数
{
keyval=keyscan();
if(keyval<10)
{
switch(c)
{
case 1:b1=keyval; break;
case 2:b2=keyval; break;
case 3:b3=keyval; break;
case 4:b4=keyval; break;
case 5:b5=keyval; break;
}
c++;
}
display1(b1,b2,b3,b4,b5);
}

while(c==6) //输入计算符号
{
keyval=keyscan();
if((keyval>=10)&&(keyval<14)) //可去一层括号,因逻辑运算优先级较低
{
d=keyval;
}
c=1;
display3(d);

}
while(c<6) //输入第2个5 位数
{
keyval=keyscan();
if(keyval<10)
{
switch(c)
{
case 1:d1=keyval; break;
case 2:d2=keyval; break;
case 3:d3=keyval; break;
case 4:d4=keyval; break;// 除
case 5:d5=keyval; break;
}
c++;
}
display2(d1,d2,d3,d4,d5);
}

bb= b1*10000+b2*1000+b3*100+b4*10+b5;
dd=d1*10000+d1*1000+d3*100+d4*10+d5;
while(keyval!=14) //等待按下"="
{
keyval=keyscan();
}
Delay1ms(10);
switch(d)
{
case 10:ee=bb+dd; break;//+
case 11:
flag1=1;
if(bb>=dd)
{
ee=bb-dd; //-
flag1=0;
}
else ee=dd-bb;
break;

case 12:ee=bb*dd; break;//*可能会溢出
case 13:ee=bb/dd; //除法小数部分会丢失,保留2位
ff=bb%dd;
fd1=ff*10/dd;
fd2=ff*100/dd%10;
break;
}
f10=ee/1000000000%10;
f9=ee/100000000%10;
f8=ee/10000000%10;
f7=ee/1000000%10;
f6=ee/100000%10;
f5=ee/10000%10;
f4=ee/1000%10;
f3=ee/100%10;
f2=ee/10%10;
f1=ee%10;
display4(f10,f9,f8,f7,f6,f4,f4,f3,f2,f1,fd1,fd2);

while(keyval!=15)
{
keyval=keyscan();
}
b1=0;b2=0;b3=0;b4=0;b5=0;
d1=0;d2=0;d3=0;d4=0;d5=0;
bb=0;dd=0;ee=0;
init2();
}
}