ad7705初始化.txt

这是AD转换芯片AD7705的初始化程序

#include <reg52.h>
#include <intrins.h>

#include "global_var.h"
#include "my_type.h"
#include "temp_interface.h"
#include "temp_constant.h"
#include "temp_function.h"

/*ad7705初始化*/
void ad7705_init()
{
	AD7705_nRST = 0;
	delay(5);//有效复位AD7705
	AD7705_nRST = 1;
	_nop_();
	
	ad7705_write(time_reg);//写时钟寄存器
	
	ad7705_write(0x44);//自校准，增益为1,单极性，无缓冲模式
}	
	
/*ad7705写状态寄存器*/
void ad7705_write(uchar ad_word)
{
	uchar i;
	AD7705_nCS = 0;
	for(i=0x80;i>=0x01;i>>=1)
	{		
		AD7705_SCK = 0;
		if(0==(ad_word&i))
			AD7705_DIO = 0;
		else
			AD7705_DIO = 1;
		AD7705_SCK = 1;//写脉冲
	}
	AD7705_DIO = 1;//拉高防干扰
	AD7705_nCS = 1;
}

/*ad7705读数据寄存器*/
uint ad7705_read()
{
	uchar i;
	uint ad_data = 0;	
	AD7705_nCS = 0;	
	for(i=0;i<16;i++)
	{
		AD7705_SCK = 0;
		if(1 == AD7705_DIO)
			ad_data++;
		ad_data<<=1;
		AD7705_SCK = 1;//读脉冲			
	}
	AD7705_DIO = 1;//拉高防干扰
	AD7705_nCS = 1;
	return ad_data;
}


void ad7705_int1() interrupt 2
{	
	uint ad_num;//模数转换数字量
	EX1 = 0;//关模数转换中断 
	ad_num = ad7705_read();//读模数转换数字量
	/*XUJIN数字滤波*/
	vt_pt100(ad_num);//得到温度
	EX1 = 1;//开模数转换中断
}