a.c

基于51

#include <stdio.h>
#include <AT89X52.h>
#include<intrins.h>
#include<absacc.h> 
#define  Dlcd  XBYTE[0x3FFF]//显示的地址
 
sbit rs = P1^0;   //1=数据; 0=指令;
sbit rw = P1^1;   //1=读; 0=写;
sbit  e = P1^2;   //1＝使能？
#define unchar  unsigned char
#define unint   unsigned int  
unchar  distab[8] ;   
unint voltage;
#define AD199   XBYTE[0x4000]

sbit HBEN= P1^4;
sbit INT197= P1^3;

/*-------------延时--------------------------*/
void delay(unsigned char i)    //225不稳定，确保安全230-250 约0.5ms
{ 
while(--i);
}

void delay1s(void) 
{ 
 unsigned char i,j,k; 
 for(k=100;k>0;k--) 
 for(i=20;i>0;i--) 
 for(j=248;j>0;j--); 
} 


/*---------------写数据------------------------*/
lcd_write_data(unsigned char c) 
{ 
delay(230);
rs=1;
rw=0;
Dlcd =c;
e=1;
_nop_();
_nop_();
e=0;
}

/*---------------写指令------------------------*/
lcd_write_command(unsigned char c) 
{ 
delay(230);
rs=0;
rw=0;
Dlcd =c;
e=1;
_nop_();
_nop_(); 
e=0;
}

/*------------------初始化-----------------*/
void init_lcd (void)
{
lcd_write_command (0x30);  //基本指令集  
lcd_write_command (0x01);  //清屏，地址指针指向00H
lcd_write_command (0x06);  //光标的移动方向
lcd_write_command (0x0c);  //开显示，关游标
}


/************************************************************************************************
lcd_write_sentence函数：
指定起始行，起始列，连续写入字符串；注意：字符串长度必须小于8；行：1－4；列：0－7
*************************************************************************************************/

void lcd_write_sentence(unchar row,unchar col,unchar *string,unchar lenth)   
{
  unchar i=0;
  lcd_write_command (0x30);
  switch(row)
  {
    case 1:
	 lcd_write_command(0x80+col);        //第一行
	 break;
	case 2:
	 lcd_write_command(0x90+col);        //第二行
	 break;
    case 3:
	 lcd_write_command(0x88+col);        //第三行
	 break;
	case 4:
	 lcd_write_command(0x98+col);        //第四行
	 break;
	 default: 
	 lcd_write_command(0x80);            //缺省为第一行
	 break;
   }
  while(lenth-->0)
  { 
    lcd_write_data(string[i]);            //写入字符串
	i++;
  }
}

unint AD199Start(unchar M)
{
  long voltage;
  unchar d_h,d_l,i;
  unint tem,max=0,min=10000;
  voltage=0;
  for(i=0;i<M+2;i++)     //连续采样N次，去掉最大值和最小值，再平均
  {         
   AD199=0x40;//开始转化
   while(INT197==1);
HBEN=0; 
   d_l=AD199;
HBEN=1;
   d_h=AD199;

   tem=d_h*0x0100+d_l;
   if(tem>max)
   max=tem;
   if(tem<min)
   min=tem;
   voltage+=tem;
  }
  voltage=voltage-max-min;
  voltage=voltage/M;
  return (unint)voltage;
}

void getAD199(void)
{
	voltage=AD199Start(10);			
	distab[7]=voltage/10000;      //分别取出显示
	voltage=voltage%10000;
  	if(distab[7]==0)
  		distab[7]=0x10;
	distab[6]=voltage/1000;
  	voltage=voltage%1000;
  	distab[5]=voltage/100;
  	voltage=voltage%100;  			
  	distab[4]=voltage/10;
	voltage=voltage%10;
	distab[3]=voltage;
	distab[2]=0x10;
 	distab[1]=0x10;
 	distab[0]=0x10;
	init_lcd ();	
	lcd_write_sentence(1,0,"The voltage is:",15); 
	lcd_write_command(0x30);
	lcd_write_command(0x90);
	lcd_write_data(0x20);
	lcd_write_data(0x30+distab[6]);   			
	lcd_write_sentence(2,1,".",1);
	lcd_write_data(0x30+distab[5]);
	lcd_write_data(0x30+distab[4]);
	lcd_write_data(0x30+distab[3]);
	lcd_write_sentence(2,3,"V",1);
}
/*------------------主程序--------------------*/
void main ()
{
init_lcd ();
getAD199();
delay1s();
}