ad7788.c

AD7788 16ｂｉｔ A/D转换程序 AD7788 16ｂｉｔ A/D转换程序

#include "common.h"
#include <iom32v.h>
#include "ad7788.h"
#include "display.h"
#include "wh_4008a.h"



/* 向AD7788写入一个字节 */
void WriteByte7788(unsigned char x)
{
uchar i;
ad7788_sclk_high;
//nop;
//nop;
for (i=0; i<8; i++)
	{
	ad7788_sclk_low;
	//nop;
	//nop;
        if((x&0x80)==0x80)
        	{
		ad7788_din_high;
        	}
	else
		{
		ad7788_din_low;
		}
        //nop;
	 //nop;
	 ad7788_sclk_high;
        //nop;
	 //nop;
	 x <<=1;
	}
}


/* 从AD7788读一个字 节*/
unsigned char ReadByte7788(void)
{
uchar i;
uchar x ;
x=0;
ad7788_sclk_high;
//nop;
//nop;
for (i = 0 ; i < 8 ; i++)
	{
      	 ad7788_sclk_low;
        nop;
      	 nop;
	 nop;
	 nop;
	 nop;
	 nop;
 	 ad7788_sclk_high; 
//	 nop;
//	 nop;
	x<<=1;	
	if(ad7788_dout_high)
		{
		x |= 0x01;
		}		
	}
return  x;
}


/* AD7788通信端口复位 */
void Reset7788(void)
{
uchar i;
for(i=0;i<50;i++)    /* 多于连续32个 DIN=1 使串口复位 */
	{
	ad7788_sclk_low;
       nop;
	nop;
       ad7788_din_high;
	nop;
	nop;
	ad7788_sclk_high;
	nop;
	nop;
       }
}





uchar adc_error_flag;

//const uchar num_tab[17]="0123456789abcdef";
ulong read_ad7788(void)
{

uchar data_high2,data_low,data_high1;
uchar temp_uchar;
ulong temp_long;

ad7788_csn_low;
//nop;
//nop;

//Reset7788();
//delay_1ms(20);



//对filter register Write
WriteByte7788(0x20);
//对filter register 写的内容:clock-Normal Mode,16.6hz 4 1.5 65 dB @ 50 Hz/60 Hz (Default Setting)
//WriteByte7788(0x04);

//对filter register 写的内容:clock-Normal Mode,33.3hz 
WriteByte7788(0x02);

//对filter register 写的内容:clock-Normal Mode,100hz 
//WriteByte7788(0x01);

//对filter register 写的内容:clock-Normal Mode,16.6hz 4 1.5 80 dB @ 50 Hz
//WriteByte7788(0x05);

//对mode register Write
//AIN(+) – AIN(–)
WriteByte7788(0x10);

//对mode register 写的内容:Single-conversion mode,unipolar,unbuffer
WriteByte7788(0x84);

//对mode register 写的内容:Single-conversion mode,unipolar,buffer
//WriteByte7788(0x86);

//对mode register 写的内容:Continuous-conversion mode,unipolar,unbuffer
//WriteByte7788(0x04);
//对mode register 写的内容:Continuous-conversion mode,unipolar,buffer
//WriteByte7788(0x06);

//adc_error_flag=false;

//等待DOUT电平拉低
while(ad7788_dout_high);


/*
while(1)
	{
	WriteByte7788(0x00);
	//nop;
	//nop;
	nop;
	temp_uchar=ReadByte7788();
	if((temp_uchar&0x80)==0x00)
		{
		//
		//putchar_test(0xbb);
		break;
		}
	}

*/
//nop;
//nop;
//nop;


/*
WriteByte7788(0x00);
temp_uchar=ReadByte7788();
if((temp_uchar&0x40)==0x40)
	{
	//putchar_test(0xcc);
	adc_error_flag=true;
	return 0;
	}
*/

WriteByte7788(0x38);

data_high2=ReadByte7788();
data_high1=ReadByte7788();
data_low=ReadByte7788();

ad7788_csn_high;
nop;
nop;


ad7788_din_high;

/*
//第二次
ad7788_csn_low;
nop;
nop;

WriteByte7788(0x10);
WriteByte7788(0x84);
WriteByte7788(0x20);
WriteByte7788(0x02);
nop;
nop;

while(ad7788_dout_high);
nop;
nop;

WriteByte7788(0x38);
nop;
nop;

data_high2=ReadByte7788();
data_high1=ReadByte7788();
data_low=ReadByte7788();


ad7788_din_high;
ad7788_csn_high;
*/
temp_long=(ulong)data_high2*0x10000+(ulong)data_high1*0x100+(ulong)data_low;
//return ((float)temp_long)*vref/16777216.0;
return temp_long;
}




ulong value_buf[AD_N];
uchar count_ad_i=0;

float read_filter_ad(void)
{
	uchar count;
	float sum=0.0;
loop1:
	value_buf[count_ad_i++]=read_ad7788();
	if(adc_error_flag==true)
		{
		adc_error_flag=false;

		//Reset7788();
		goto loop1;
		//led_buffer[14]='b';
		
		}
	else
		{
		//led_buffer[14]='a';
		}
	
	if (count_ad_i >= AD_N) 
		{
		count_ad_i=0;
		}
	for ( count=0;count<AD_N;count++)
		{
		sum =sum+ value_buf[count];
		}
	return (((float)sum)*vref/(AD_N*16777216.0));
}




//tiaoshi
ulong read_filter_ad_test(void)
{
	uchar count;
	ulong sum=0.0;
	
	value_buf[count_ad_i++]=read_ad7788();
	
	if (count_ad_i >= AD_N) 
		{
		count_ad_i=0;
		}
	for ( count=0;count<AD_N;count++)
		{
		sum =sum+ value_buf[count];
		}
	return (sum/AD_N);
}

//tiaoshi end