我用的是AD7799BRUZ芯片，打算应用于称重。
电路连接参照数据手册(Rev.0) 27页的那个电路，
我只用了AIN1一个通道，其余未用。
出现的问题是：采不出数据。
进行满量程校准后读出的数据全为FF，读状态寄存器有错误标志。把REF_DEC置位后有NOREF错误标志，可是我的参考电压接是是正5V啊，是不是AD7799内部的参考电压电路部分损坏了啊！！
#include <intrins.h> /* use _nop_() function */
/*
AD7799写寄存器函数
WriteData：要写的数据
*/
void WriteByteToAd7799(unsigned char WriteData)
{
unsigned char i;
//AD7799_CS=0;
for(i=0;i<8;i++)
{
AD7799_SCLK=0;
if(WriteData&0x80)AD7799_DIN=1;
else AD7799_DIN=0;
WriteData=WriteData<<1;
AD7799_SCLK=1;
}
//AD7799_CS=1;
}
/*
AD7799读寄存器函数
*/
unsigned char ReadByteFromAd7799(void)
{
unsigned char i;
unsigned char ReadData;
//AD7799_CS=0;
ReadData=0;
for(i=0;i<8;i++)
{
AD7799_SCLK=0;
ReadData=ReadData<<1;
if(AD7799_DOUT)ReadData+=1;
AD7799_SCLK=1;
}
//AD7799_CS=1;
return(ReadData);
}
void WaiteRDY(void)
{
unsigned int iint;
iint=0;
while(AD7799_RDY)
{
iint++;
if(iint>20000)
{
//reset ad7799
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
for(iint=0;iint<1000;iint++)
{
_nop_();
_nop_();
}
Ad7799_Ini(0);
break;
}
}
}
void Ad7799_Ini(unsigned char ChannelNum)
{
WriteByteToAd7799(0x10);//b0000 1000
/* Writes to Communications Register Setting Next Operation as Write to
CONFIGURATION Register*/
WriteByteToAd7799(0x00); //增益为0
WriteByteToAd7799(0x10+ChannelNum); //1通道
/*CONFIGURATION REGISTER[00,BO(0),U/B(0),
0(0),G2(1),G1(1),G0(1),0,0,REF_DET(0),BUF(1),0(0),CH2(0),CH1(0),CH0(0)]*/
WriteByteToAd7799(0x08); //b0000 1000
/* Writes to Communications Register Setting Next Operation as Write to
Mode Register*/
WriteByteToAd7799(0x80);
WriteByteToAd7799(0x0a);
/* Writes to Mode Register Initiating Internal Zero-Scale Calibration*/
WaiteRDY();
/* Wait for RDY pin to go low to indicate end of calibration cycle*/
WriteByteToAd7799(0x08);
/* Writes to Communications Register Setting Next Operation as Write to
Mode Register*/
WriteByteToAd7799(0xa0);
WriteByteToAd7799(0x0a);
/* Writes to Mode Register Initiating Internal Full-Scale Calibration*/
WaiteRDY();
/* Wait for RDY pin to go low to indicate end of calibration cycle*/
WriteByteToAd7799(0x08); //b0000 1000
/* Writes to Communications Register Setting Next Operation as Write to
Mode Register*/
WriteByteToAd7799(0x00);
WriteByteToAd7799(0x0A);
/* Mode Register[MD2(0),MD1(0),MD0(0),PSW(0),0(0),0(0),0(0),0(0),
(0),(0),0(0),0(0),FS3(1),FS2(0),FS1(1),FS0(0)]*/
/*模式0 Continuous-Conversion Mode.，Fadc=16.7HZ;*/
}
long ReadAd7799ConversionData(void)
{
long ConverData;
unsigned char ADSAT;
unsigned int iint;
WaiteRDY();
WriteByteToAd7799(0x40);
ADSAT=ReadByteFromAd7799();
if((ADSAT&0x40)||(ADSAT& 0x08)==0) //出错或者读写异常
{
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
WriteByteToAd7799(0xff);
for(iint=0;iint<3000;iint++)
{
_nop_();
}
Ad7799_Ini(0);
return(0);
}
else
{
WriteByteToAd7799(0x58);
/* Writes to Communications Register Setting Next Operation as Continuous
Read From Data Register*/
WaiteRDY();
/* Wait for RDY pin to go low to indicate end of calibration cycle*/
if(!AD7799_RDY)
{
ConverData=0;
ConverData=ReadByteFromAd7799();
ConverData=ConverData<<8;
ConverData=ReadByteFromAd7799()+ConverData;
ConverData=ConverData<<8;
ConverData=ReadByteFromAd7799()+ConverData;
}
/* Read Conversion Result from AD7730's Data Register*/
return(ConverData);
}
}
#include <reg52.h>
#include "ad7799.h"
idata long addata;
main()
{
Ad7799_Ini(0);
while(1)
{
addata=ReadAd7799ConversionData();
}
}
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