c语言简易计算器程序(带解释)

sbit KeyIn1 = P2^4;
sbit KeyIn2 = P2^5;
sbit KeyIn3 = P2^6;
sbit KeyIn4 = P2^7;
sbit KeyOut1 = P2^3;
sbit KeyOut2 = P2^2;
sbit KeyOut3 = P P2^0;
}
for (;i>=1; i--, sit/=10)
{
Led_buf[i] = Ledcode[i_num/sit];
i_num -= i_num/sit*sit;
}
Led_buf[0] = Ledcode[i_num] & 0x7F;
if (s_flag) /*如果标志为1，负值*/
{
s_flag = 1;
i_num = -i_num;
}
ET0 = 0;
for (i=4, sit=10000 ; i>=1; i--, sit/=10)
/*特殊for语句，如果i>=1,那么执行for语句内部，执行完再i--，且sit=10000/10=1000*/
sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;
sbit BUZZ = P1^6;
#define FADD 10
#define FSUB 11
#define FMUL 12
Led_buf[i] = Ledcode[10]; /*11号元素0xFF,即6管都不显示,或者说显示清零*/
Led_buf[5] = Ledcode[12]; /*第六管显示“E"*/
}
/*制作数码管整数数据，i_num是输入的数值*/
/*与显示浮点数不同的是不用扩大必要的倍数以去除小数点，且不用记住有效小数的小数位数*/
{
uint16 i;
for (i=0; i<BUZ_DELAY; i++)
{
BUZZ = ~BUZZ;
delay(100);
}
BUZZ = 1;
}
/* 按键扫描，返回所按下的键值。若两键同时反应，即使前键返回一个值，后键也返回一个值，val也等于后者*/
{
if (i_num >= sit) /*i_num输入数值的绝对值若大于10000，那么跳出for循环*/
break;
Led_buf[i] = Ledcode[10]; /*若不大于10000，Led_buf[4]=Ledcode[10]=0xFF不显示*/
i_num -= i_num/sit*sit; /*i_num=i_num-i_num/sit*sit*/
}
if (KeyIn4 == 0)
{
delay(KEY_DELAY);
if (KeyIn4 == 0)
val = FDIV; /*13*/
}
while ((KeyIn1 == 0)||(KeyIn2 == 0)||(KeyIn3 == 0)||(KeyIn4 == 0));
#define FDIV 13
#define FRES 14
#define FEQU 15
#define KEY_DELAY 300
#define BUZ_DELAY 80
code uint8 Ledcode[13]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xff,0xbf,0x86};
if (val > 0)
buzzer_sound(); /*蜂鸣器响一段时间停止鸣叫*/
return val;
}
/*验证数据有效性，太大则返回1，小则返回0，这里太大其实受6管中最高位显示正负，其余5个管子显示
最大11111的限制，数值大于11111就是100000以上已经不能显示了*/
typedef unsigned int uint16; /*0-65535*/
typedef unsigned long uint32; /*0到2^32-1*/
typedef char int8;
typedef int int16;
typedef long int32;
int16 sit; /*-32768=2^-16到32767，*/
int8 i, decimal, dot_sit=0;
/*运算扩大后的num值，得到f_num的小数位数（人为选定最大4位），存在decimal； dot_sit是f_num的可以显示
void make_led_fnumber(float f_num) /*形参是float型，范围虽很大，但不计小数点最大共7位（十进制形式）*/
{
bit s_flag=0; /*负数标志，f_num负为1*/
int32 num; /*num用于暂存浮点数据f_num经过扩大后的值*/
int8 scan_key(void)
{
int8 val=-1; /*未按下任何键，val=-1*/
KeyOut1 = 0; /*选中1列*/
KeyOut2 = 1;
KeyOut3 = 1;
KeyOut4 = 1;
if (KeyIn1 == 0)
{
delay(KEY_DELAY);
{
delay(KEY_DELAY);
if (KeyIn4 == 0)
val = FMUL; /*12*/
}
while ((KeyIn1 == 0)||(KeyIn2 == 0)||(KeyIn3 == 0)||(KeyIn4 == 0));
KeyOut1 = 1;
bit check_num(float f_num)
{
if (f_num >= 100000)
return 1;
return 0;
}
/*制作数码管错误标志*/
void make_led_error(void)
{
int8 i;
for (i=0; i<5; i++)
delay(KEY_DELAY);
if (KeyIn2 == 0)
val = FRES; /*14清除*/
}
if (KeyIn3 == 0)
{
delay(KEY_DELAY);
if (KeyIn3 == 0)
val = FEQU; /*15等于*/
KeyOut1 = 1;
KeyOut2 = 1;
KeyOut3 = 0; /*选中3列*/
KeyOut4 = 1;
if (KeyIn1 == 0)
{
delay(KEY_DELAY);
if (KeyIn1 == 0)
val = 7;
}
if (KeyIn2 == 0)
if (KeyIn1 == 0)
val = 1;
}
if (KeyIn2 == 0)
{
delay(KEY_DELAY);
if (KeyIn2 == 0)
val = 2;
}
if (KeyIn3 == 0)
{
delay(KEY_DELAY);
KeyOut2 = 1;
KeyOut3 = 1;
KeyOut4 = 0; /*选中4列*/
if (KeyIn1 == 0)
{
delay(KEY_DELAY);
if (KeyIn1 == 0)
val = 0;
}
if (KeyIn2 == 0)
{
void make_led_inumber(int32 i_num) /*形参是整数型的*/
{
bit s_flag=0; /*sflag是i_num为负值时的标志，输入负值时等于1*/
int16 sit; /*权位*/
int8 i;
if (i_num < 0)
/* Easy calculator
K4:+ K8:- K12:* K16:/ K14:Clear K15:=
*/
/*程序要点已做说明，初学者肯定有用*/
#include <reg52.h>
typedef unsigned char uint8; /*0-255，signed char -128到127*/
/*0-9; 关闭；负号; E 共13个*/
uint8 Led_n=0; /*数码管编号*/
uint8 Led_buf[6]; /*数码管显示时编码*/
float Tmp1=0, Tmp2=0; /*暂存用实数变量，范围？float 32位 6或7位有效数字(这里为7位），范围 -3.4*10(-38)～3.4*10(38)*/
if (KeyIn3 == 0)
val = 6;
}
if (KeyIn4 == 0)
{
delay(KEY_DELAY);
if (KeyIn4 == 0)
val = FSUB; /*11*/
}
while ((KeyIn1 == 0)||(KeyIn2 == 0)||(KeyIn3 == 0)||(KeyIn4 == 0));