温度传感器AD7416接口程序 - Copywright www.dailzh.com  
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 /***************************************************
* License: Full Free under GPL * 
* Author: Dailizhou in HIT *
* URL: http://www.dailzh.com * 
****************************************************/
#pragma small
#include<reg51.h>
#include<intrins.h>
sbit Second_Led=P2^4;
sbit Power_OnOff=P2^5;
sbit Led1=P2^0;
sbit Led2=P2^1;
sbit Led3=P2^2;
sbit Led4=P2^3;
sbit ks=P1^0;
sbit ku=P1^1;
sbit kd=P1^2;
sbit LE=P0^6;
sbit SDA = P3^5;
sbit SCL = P3^4;
sbit DS_CLK = P1^3;
sbit DS_IO = P1^4;
sbit DS_RST = P1^5;
char cp=0,cp1=0,di=0,cps=0,cpt,cps1;
char buf[4],d=0,c,dt[7];
char disp_mode;
typedef struct
{
unsigned char h,m,t;
}SEG_CT;
SEG_CT seg_ct[10];
/**************** IIC Access Function *******************/
/* Author: Dai LiZHou */
/* Date: 1999.8.24 */
/* Last Date: 1999.8.24 */
/********************************************************/
/********** Function Declare Begin **********************/
char Start(); /* Start IIC bus for reading or writing*/
void Stop(); /* Stop IIC bus */
char Shin(); /* Shift a byte from EEPROM, */
/* most significant first */
void Shout(char Byte); /* Shift a byte to EEPROM */
char TestAck(); /* check if Acknowledge bit is valid */
/********** Function Declare End *************************/
char Start()
{
SCL=1; /* release SCL */
SDA=1; /* release SDA */
_nop_();
_nop_();
_nop_();
_nop_();
if( SCL==0 || SDA==0 ) return 0; /* IIC bus not available, Start false */
else
{
SCL=1; /* Send start operation */
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
SDA=0; /* SDA high-to-low when SCL high */
_nop_();
_nop_();
_nop_(); /*one cycle delay function */
_nop_(); /*declare in <intrins.h> */
_nop_();
SCL=0;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
SDA=1; /*release SDA */
}
} /*return with SDA high, SCL low */
void Stop()
{
SDA=0;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
SCL=1;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
SDA=1; /* SDA low-to-high when SCL high, return with SCL SDA high */
}
char Shin()
{
char i,RetByte;
for(i=0;i<8;i++)
{
SCL=0;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
SCL=1;
_nop_();
_nop_();
RetByte=RetByte<<1;
if( SDA==1 ) RetByte=RetByte|0x01;
}
SCL=0;
_nop_();
_nop_(); /* return with SCL low, SDA high */
SDA=1;
return RetByte;
}
void Shout( char Byte )
{ /* Send one byte to EEPROM */
/* most significant */
char i;
for(i=0;i<8;i++)
{
SCL=0;
_nop_();
_nop_();
if( Byte&0x80 ) SDA=1;
else SDA=0;
_nop_();
_nop_();
Byte=Byte<<1;
SCL=1;
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
}
SCL=0;
_nop_();
_nop_();
_nop_();
_nop_();
SDA=1; /* return with SCL low , SDA high */
}
char TestAck()
{
char rf=0; /* return flag */
SCL=0;
_nop_();
_nop_();
_nop_();
SDA=1; /* release SDA */
_nop_();
_nop_();
SCL=1;
_nop_();
_nop_();
_nop_();
_nop_();
if( SDA==1 ) rf=1; /* Acknowledge bit is invalid*/
else rf=0;
SCL=0;
_nop_();
_nop_();
_nop_();
return rf;
}
unsigned int LM74_Read(void)
{
unsigned char rc_h=0, rc_l=0,i;
unsigned int bbData,sum;
Start();
Shout( 0x90 ); /* send device address & write command */
if( !TestAck() )
{
Shout(0);
TestAck();
}
Stop;
sum=0;
for(i=0;i<10;i++)
{
Start();
Shout( 0x91 ); /* send device address & write command */
if( !TestAck() )
{
rc_h=Shin();
if( !TestAck() )
rc_l=Shin();
TestAck();
}
Stop();
bbData=rc_h;
bbData=_irol_(bbData,8);
bbData=bbData|rc_l;
bbData=_iror_(bbData,6);
bbData=bbData&0x0FFF;
sum+=bbData;
}
bbData=sum/10;
return (bbData);
}
void LM74_Set(void)
{
unsigned char rc_h, rc_l;
unsigned int bbData;
Start();
Shout( 0x90 ); /* send device address & write command */
if( !TestAck() )
{
Shout( 1 ); /* send byte address to read */
if( !TestAck() )
{
Shout(0x0);
TestAck();
}
}
Stop();
Start();
Shout( 0x91 ); /* send device address & write command */
if( !TestAck() )
{
rc_l=Shin();
TestAck();
}
Stop();
}