calc.c

AT89C51开发例程 protues仿真 keil编程

#include"calc.h"


void main(void)
{
	init();	//键盘定时扫描初始化
	status=0;
	display(0);
	//getkey();
	while(1)
	{
		Refresh(ledbuf);
	}
}

void display(signed long x)
{
	signed long data t;
	unsigned long data tc;
	int data i,p,tp;
	int fst=0;
	for(i=0;i<MAX_DISPLAY_CHAR;i++)
	{
		ledbuf[i]=0xff;
	}
	t=x;
	if(x>=100000000||x<=-10000000){return;}//整数溢出
	else if(x>=10000000||x<=-1000000){i=8;}
	else if(x>=1000000||x<=-100000){i=7;}
	else if(x>=100000||x<=-10000){i=6;}
	else if(x>=10000||x<=-1000){i=5;}
	else if(x>=1000||x<=-100){i=4;}
	else if(x>=100||x<=-10){i=3;}
	else if(x>=10||x<0){i=2;}
	else{i=1;}

	if(x<0)
	{
		ledbuf[--i]=0x2d;//负号处理
		t*=-1;
	}
	 
	for(p=i-1;p>=0;p--)
	{
		tc=1;
		for(tp=p;tp>0;tp--) tc*=10; 
		ledbuf[p]=t/tc;
		t=t-(ledbuf[p]*tc);
	}
	for(i=MAX_DISPLAY_CHAR-1;i>=0;i--)
	{
		if(fst!=0||ledbuf[i]!=0||i==0)
		{
			ledbuf[i]=value2led(ledbuf[i]);
			fst=1;
		}
		else 
		{
			ledbuf[i]=0xff;		
		}
	}
	return;
}

char value2led(char ch)
{
	switch(ch)
	{
		case 0x00: return 0xc0;
		case 0x01: return 0xf9;
		case 0x02: return 0xa4;
		case 0x03: return 0xb0;
		case 0x04: return 0x99;
		case 0x05: return 0x92;
		case 0x06: return 0x82;
		case 0x07: return 0xf8;
		case 0x08: return 0x80;
		case 0x09: return 0x90;
		case 0x2d: return 0xbf;
	}
}

void getkey (void) interrupt 1 using 0
//定时扫描键盘 
{
	char data mykey;
  	mykey = input();
	if(mykey==0)
	{
		return;
	}
	else
	{
		calc(mykey);
	}
  return;
 }

void calc(char cur)
{
	if(cur=='0')cur=0;
	if(cur>=0x00&&cur<=0x09)
		digits(cur);
	else
		operator(cur);
	return;
}
void digits(char dt)
{
	if(status==0)
	{
		if(lvalue>=10000000) return;
		lvalue*=10;
		lvalue+=dt;
		display(lvalue);
	}
	else if(status==1)
	{
		if(rvalue>=10000000) return;
		rvalue*=10;
		rvalue+=dt;
		display(rvalue);
	}
	return;
}
void operator(char op)
{
	status++;
	switch(op)
	{
		case '+':
		case '-':
		case '*':
		case '/':
			if(status==1||status==0)
			{
				lasttoken=op;
			}
			else if(status==2)
			{
				deal();
			}
			status=1;
			break;
		case '=':
			if(lasttoken==0) return;
			deal();
			status=0;
			break;
		case 'C':
			lasttoken=op;
			deal();
			status=0;
			break;
		case 'S':
			lasttoken=op;
			deal();
			status=0;
	}
	return;
}

void deal()
{
	long result=0;
	long num;
	switch(lasttoken)
	{	
		case '+':
			result=lvalue+rvalue;
			break;
		case '-':
			result=lvalue-rvalue;
			break;
		case '*':
			result=lvalue*rvalue;
			break;
		case '/':
			if(rvalue==0) return;
			result=lvalue/rvalue;
			break;
		case 'C':
			lasttoken=0;
			break;
		case 'S':
			if(status==2&&rvalue!=0) num=rvalue;
			else num=lvalue;
			result=square((double)num);
			lasttoken=0;			
			break;
	}
	if(result>=100000000)result=0;
	lvalue=result;
	display(lvalue);
	rvalue=0;
	return;
}
long absc(long dt)
{
	if(dt>=0) return dt;
	else return dt*(-1);
}

int square(double dt)
{
	double result;
	result=dt/2;
    while (absc(result*result-dt)>1)
    result=(result+dt/result)/2;
	return result;
}