fad.c

电子罗盘fad-dcm-spi的源程序

#include<reg52.h>
#include<absacc.h>
#include<string.h>
#include<intrins.h>
sbit CS=P0^3;		//FAD管脚定义
sbit SI=P0^2;
sbit SO=P0^1;
sbit SCK=P0^0;
unsigned char S_data,t1,t2,t3,t4;
void write_onebyte(unsigned char qq);
unsigned char  read_onebyte(void);
void DelayMs(unsigned int tt);
void main()
{
      CS=0;
      write_onebyte(0x5a);      
      //write_onebyte(0x01);
      SI=0;
      //DelayMs(5);
      t1=read_onebyte();
      DelayMs(5);
      write_onebyte(0x5a);
      t2=read_onebyte();
      DelayMs(5);
      t3=read_onebyte();
      DelayMs(5);
      t4=read_onebyte();
      while(1);
}
void write_onebyte(unsigned char qq)
{
	unsigned char i;
	for(i=0;i<8;i++)
	{
		SCK=0;
		SI=(bit)(qq&0x80);         //发送8位数据，先送最高位
		qq<<= 1;
		SCK=1;
	}
	SCK=0;//SI=0;
}
//====================================================================
//函数原型：unsigned char  read_onebyte(void)
//功    能：从FAD接收一个字节
//====================================================================
unsigned char  read_onebyte(void)
{
        
       	unsigned char  i;
        S_data=0;SI=0;
	for(i=0;i<8;i++)
	{
		S_data <<= 1;               //接收8位数据，先接收最高位
		SCK=0;
		SCK=1;

		if(SO)
		  S_data++;
	}
        return(S_data) ;
}
 void DelayMs(unsigned int tt)
     {
           unsigned int  p,delay0;
           for(p=0;p<tt;p++)
           for(delay0=0;delay0<1000;delay0++);
     }