最佳答案

#include

#include

#include /* isdigit()函数 */

#include /* atoi()函数 */

#define uchar unsigned char

#define uint unsigned int

uchar operand1[9], operand2[9]; /* 操作数 */

uchar operator; /* 操作符 */

void delay(uint);

uchar keyscan();

void disp(void);

void buf(uint value);

uint compute(uint va1,uint va2,uchar optor);

uchar code table[] = {0xc0,0xf9,0xa4,0xb0,0x99,

0x92,0x82,0xf8,0x80,0x90,0xff}; /* 字符码表 */

uchar dbuf[8] = {10,10,10,10,10,10,10,10}; /* 显示缓存 */

/* 延时函数 */

void delay(uint z)

{

uint x,y;

for(x=z;x>0;x--)

for(y=110;y>0;y--);

}

/*******************************************

键盘扫描程序

将按键转化为字符并作为输出

'$','#'分别表示清零键和没有键按下

*******************************************/

uchar keyscan()

{

uchar skey; /* 按键值标记变量 */

/***********************

扫描键盘第1行

************************/

P1 = 0xfe;

while((P1 & 0xf0) != 0xf0) /* 有按键按下 */

{

delay(3); /* 去抖动延时 */

while((P1 & 0xf0) != 0xf0) /* 仍有键按下 */

{

switch(P1) /* 识别按键并赋值 */

{

case 0xee: skey = '7'; break;

case 0xde: skey = '8'; break;

case 0xbe: skey = '9'; break;

case 0x7e: skey = '/'; break;

default: skey = '#';

}

while((P1 & 0xf0) != 0xf0) /* 等待按键松开 */

;

}

}

/***********************

扫描键盘第2行

************************/

P1 = 0xfd;

while((P1 & 0xf0) != 0xf0)

{

delay(3);

while((P1 & 0xf0) != 0xf0)

{

switch(P1)

{

case 0xed: skey = '4'; break;

case 0xdd: skey = '5'; break;

case 0xbd: skey = '6'; break;

case 0x7d: skey = '*'; break;

default: skey = '#';

}

while((P1 & 0xf0) != 0xf0)

;

}

}

/***********************

扫描键盘第3行

************************/

P1 = 0xfb;

while((P1 & 0xf0) != 0xf0)

{

delay(3);

while((P1 & 0xf0) != 0xf0)

{

switch(P1)

{

case 0xeb: skey = '1'; break;

case 0xdb: skey = '2'; break;

case 0xbb: skey = '3'; break;

case 0x7b: skey = '-'; break;

default: skey = '#';

}

while((P1 & 0xf0) != 0xf0)

;

}

}

/***********************

扫描键盘第4行

************************/

P1 = 0xf7;

while((P1 & 0xf0) != 0xf0)

{

delay(3);

while((P1 & 0xf0) != 0xf0)

{

switch(P1)

{

case 0xe7: skey = '$'; break;

case 0xd7: skey = '0'; break;

case 0xb7: skey = '='; break;

case 0x77: skey = '+'; break;

default: skey = '#';

}

while((P1 & 0xf0) != 0xf0)

;

}

}

return skey;

}

void main()

{

uint value1, value2, value; /* 数值1,数值2,结果 */

uchar ckey, cut1 = 0, cut2 = 0; /* ckey键盘输入字符 */

uchar operator; /* 运算符 */

uchar i, bool = 0;

init: /* goto语句定位标签 */

buf(0); /* 初始化 */

disp();

value = 0;

cut1 = cut2 = 0;

bool = 0;

for(i = 0;i < 9;i++)

{

operand1[i] = '\0';

operand2[i] = '\0';

} /* 初始化 */

while(1)

{

ckey = keyscan(); /* 读取键盘 */

if(ckey != '#')

{ /* isdigit函数，字符是阿拉伯数字返回非0值，否则返回0 */

if(isdigit(ckey))

{

switch(bool)

{

case 0:

operand1[cut1] = ckey;

operand1[cut1+1] = '\0';

value1 = atoi(operand1); /* atoi函数，将字符串转化为，int整数 */

cut1++;

buf(value1);

disp();

break;

case 1:

operand2[cut2] = ckey;

operand2[cut2+1] = '\0';

value2 = atoi(operand2);

cut2++;

buf(value2);

disp();

break;

default: break;

}

}

else if(ckey=='+'||ckey=='-'||ckey=='*'||ckey=='/')

{

bool = 1;

operator = ckey;

buf(0);

dbuf[7] = 10;

disp();

}

else if(ckey == '=')

{

value = compute(value1,value2,operator);

buf(value);

disp();

while(1) /* 计算结束等待清零键按下 */

{

ckey = keyscan();

if(ckey == '$') /* 如果有清零键按下跳转到开始 */

goto init;

else

{

buf(value);

disp();

}

}

}

else if(ckey == '$')

{ goto init;}

}

disp();

}

}

/******************************************

运算函数

输入：操作数和操作符

输出：计算结果

*******************************************/

uint compute(uint va1,uint va2,uchar optor)

{

uint value;

switch(optor)

{

case '+' : value = va1+va2; break;

case '-' : value = va1-va2; break;

case '*' : value = va1*va2; break;

case '/' : value = va1/va2; break;

default : break;

}

return value;

}

/*******************************************

更新显示缓存

输入：无符号整数

输出：将输入送入显示缓存

*******************************************/

void buf(uint val)

{

uchar i;

if(val == 0)

{

dbuf[7] = 0;

i = 6;

}

else

for(i = 7; val > 0; i--)

{

dbuf[i] = val % 10;

val /= 10;

}

for( ; i > 0; i--)

dbuf[i] = 10;

}

/*******************************************

显示函数

*******************************************/

void disp(void)

{

uchar bsel, n;

bsel=0x01;

for(n=0;n<8;n++)

{

P2=bsel;

P0=table[dbuf[n]];

bsel=_crol_(bsel,1);

delay(3);

P0=0xff;

}

}

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