main.c

这个K型热电偶MAX6675的驱动程序

#include "io430.h"
#include "in430.h"
unsigned int byte,bytee,t;
 
void Delay(unsigned int n)
 {
  unsigned int j;
  for(j=0;j<n;j++)
   {
    ;
   }
  }
void max6675_display(unsigned int x) 
      {       
       unsigned int temp[5]={0,0,0,0,0}; 
       unsigned int n,m,t;
       m=10237.5*x/4095;
       temp[0]=m/10000; 
       n=m-temp[0]*10000; 
       temp[1]=n/1000; 
       n=n-temp[1]*1000; 
       temp[2]=n/100; 
       n=n-temp[2]*100; 
       temp[3]=n/10; 
       n=n-temp[3]*10; 
       temp[4]=n/1;
       t=temp[4];
       
     }

unsigned int read_max6675(void) 
  {    
       byte=0;
       unsigned int i=0; 
       P2OUT &=~BIT6;                    //CS=0,P2.6输出低电平
       P1OUT &=~BIT1;                    //SCK=0    
       //Delay(10); 
        for(i=0;i<16;i++) 
         { 
           Delay(10);
           P1OUT |=BIT1;                 //SCK=1 
            Delay(10);
           if(P1IN&BIT0)
           //byte+=1;
           // byte<<=1;
           byte|=(1<<(15-i));
           P1OUT &=~BIT1;                //SCK=0  
         }
        P2OUT |=BIT6;                    //CS=1 
        P1OUT &=~BIT1;//SCK=0 
        bytee=byte;
        if(bytee&0x8000)byte=0xfe;
        else if(bytee&0x4)byte=0xff;
        else
         {
           byte=byte&0x7ff8;
           byte=byte>>3;
           //byte=byte>>2;
          }
       return byte;
  } 


int main( void )
{  P1DIR &=~BIT0;   // P1.0为输入
   P1DIR |=BIT1;    //P1.1作输出
   P1SEL=0;
   P2DIR |=BIT6;   //P2.6作输出
   P2SEL=0;  
 
 
  while(1)
  {
    Delay(1000);           //延时
    t=read_max6675();      //读取温度
    max6675_display(t);    //显示温度值
    Delay(1000);     
  }
}