max1972.c

MAX197子程序,实现12位AD转换,高精度高速转换

				  //MAX197
//注意：我用的是外部电源供电，用内部电源失败。。。
//REF接的电压不是基准电压，要乘以一个参数才可以用，REFADJ要接高电平
#include <reg51.h>
#include<absacc.h> 
#include <intrins.h>
#define  delayNOP(); {_nop_();_nop_();_nop_();_nop_();_nop_();};
#define uchar unsigned char
#define uint unsigned int
sbit ADINT=P2^3;
sbit CS=P2^4; 
sbit MAX197_WR=P2^5;
sbit MAX197_RD=P3^6;
sbit HBEN=P2^7;

/*************************LCD************************/
#define  LINE1     0
#define  LINE2     1
#define  LINE1_HEAD    0x80
#define  LINE2_HEAD    0xC0
#define  LCD_DELAY_TIME   40
#define  DATA_MODE    0x38
#define  OPEN_SCREEN    0x0C
#define  DISPLAY_ADDRESS   0x80
#define  CLEARSCREEN    LCD_en_command(0x01)
//common part 
#define  HIGH   1
#define  LOW    0
#define  TRUE    1
#define  FALSE    0
#define  ZERO    0 
#define  MSB    0x80
#define  LSB    0x01
#define  LCDIO      P3
sbit LCD1602_RS=P2^0;  
sbit LCD1602_RW=P2^1;  
sbit LCD1602_EN=P2^2;
unsigned char code tab[]={'0','1','2','3','4','5','6','7','8','9'};
/***************************************************************/
/******************** LCD PART *************************************/
void LCD_delay(void)   
{
 unsigned char i;
 for(i=LCD_DELAY_TIME;i>ZERO;i--)//be sure lcd reset
   ;
}
/********************************************************************/  
void LCD_en_command(unsigned char command)
{
 LCDIO=command;
 LCD1602_RS=LOW;   
 LCD1602_RW=LOW;
 LCD1602_EN=LOW;
 LCD_delay();
 LCD1602_EN=HIGH;
}
/********************************************************************/
void LCD_en_dat(unsigned char dat)
{
 LCDIO=dat;
 LCD1602_RS=HIGH;
 LCD1602_RW=LOW;
 LCD1602_EN=LOW;
 LCD_delay();
 LCD1602_EN=HIGH;
}
/********************************************************************/
void LCD_set_xy( unsigned char x, unsigned char y )
{
 unsigned char address;
 if (y == LINE1) 
  address = LINE1_HEAD + x;
 else 
     address = LINE2_HEAD + x;
 LCD_en_command(address); 
}
/********************************************************************/
void LCD_write_char( unsigned x,unsigned char y,unsigned char dat)
{
 LCD_set_xy( x, y ); 
 LCD_en_dat(dat);
}
/********************************************************************/
void LCD_write_string(unsigned char X,unsigned char Y,unsigned char *s)
{
    LCD_set_xy( X, Y ); //set address 
    while (*s)  // write character
    {
     LCDIO=*s;
        LCD_en_dat(*s);   
 s ++;
    }
}
/********************************************************************/
void LCD_init(void)
{ 
 CLEARSCREEN;//clear screen 
 LCD_en_command(DATA_MODE);//set 8 bit data transmission mode 
 LCD_en_command(OPEN_SCREEN);//open display (enable lcd display)
 LCD_en_command(DISPLAY_ADDRESS);//set lcd first display address 
 CLEARSCREEN;//clear screen
}
/********************************************************************/
/*********************** OTHER PART *********************************/
void delay_nms(unsigned int n)      
{
    unsigned int i=0,j=0;
    for (i=n;i>0;i--)
     for (j=0;j<1140;j++);  
}
/********************************************************************/

uint max197(uchar COMMAND)					//使用内部基准
{
uint CH0Data;	
uchar CH0DataL,CH0DataH; 
MAX197_RD=1	;
CS=0;
MAX197_WR=0; 
P1=COMMAND;
_nop_();
MAX197_WR=1;
while(ADINT)  ;
MAX197_RD=0;
HBEN=0;
_nop_();
CH0DataL=P1;
HBEN=1;
_nop_();
CH0DataH=P1;
MAX197_RD=1;
CS=1;
CH0Data=(uint)(CH0DataH)*256+(uint)(CH0DataL);
return(CH0Data);
}
/***************************************************************/
uchar *change(uint dd)
{ 
uint c;
uchar ddd[3];
c=dd/4.096*0.61 ;
ddd[0]=tab[c/100] ;
ddd[1]=tab[c%100/10];
ddd[2]=tab[c%10] ;
return(ddd)	  ;
}
/***************************************************************/
void main()
{ uint chan;
uchar *zhi; 
LCD_init(); 
CLEARSCREEN;
delay_nms(2);
LCD_write_string(1,LINE1,"Work");
while(1)
 {
chan=max197(0x40);
zhi=change(chan);
LCD_write_string(1,LINE1,"Working...");
LCD_write_char(0,LINE2,*zhi);
LCD_write_string(1,LINE2,".");
LCD_write_char(2,LINE2,*(zhi+1));
LCD_write_char(3,LINE2,*(zhi+2));

  }

  }