我的AVR资料[程序篇] DS18B20驱动代码(源码18)

正点原子

      深夜发帖！这是avr驱动DS18B20的源码，数码管显示温度。源码如下： 
#include <mega16.h>
#include<delay.h>   
#define CLRBIT(x,y) (x&=~(1<<y))//set appoint bit low 
#define SETBIT(x,y) (x|=(1<<y))//set appoint bit high
#define CHKBIT(x,y) (x&(1<<y))//get appoint bit level
#define uchar unsigned char
#define uint unsigned int
//reset ds1820
void res1820 (void)    // Reset TX
{                
 SETBIT(DDRA,0);//SET PA0 OUTPUT
    CLRBIT(PORTA,0);//PA0 0
    delay_us(750);          // Approx 750 uS
    SETBIT(PORTA,0);//PA0 1
    delay_us(15);//15US
}
//wait for presence of 1820
void check1820 (void)    // Wait for Presence RX 'ó?úó|'e
{  
 CLRBIT(DDRA,0);//SET PA0 INPUT
    while (CHKBIT(PINA,0));
    while (!CHKBIT(PINA,0));
    delay_us(40);//??
}
//read bit data from 1820
unsigned char read1820bit (void)     // read one bit
{
    unsigned char dat;
 SETBIT(DDRA,0);//SET PA0 OUTPUT
    CLRBIT(PORTA,0);
 delay_us(1);
    SETBIT(PORTA,0);
 CLRBIT(DDRA,0);//SET PA0 INPUT
 delay_us(2);
    dat=0X01&CHKBIT(PINA,0);
    delay_us(40);          
    return (dat);
}
//read one byte from 1820
unsigned char read1820byte (void)    // read one byte
{       
    unsigned char i,j,dat;
    dat=0;
 for (i=1;i<=8;i++)
 {
        j = read1820bit ();
        dat = (j << 7) | (dat >> 1);
    }
    return (dat);
}
//write one byte to 1820
void write1820byte (unsigned char dat)    // write one byte
 {            
    unsigned char j;
    unsigned char testb;
 SETBIT(DDRA,0);//SET PA0 OUTPUT;
    for (j=1;j<=8;j++) {
        testb=dat&0x01;
        dat=dat>>1;
        if (testb)
        {
            CLRBIT(PORTA,0);                           // Write 1
            delay_us(2);                           
            SETBIT(PORTA,0);
            delay_us(45);            
        }
        else
        {
            CLRBIT(PORTA,0);                          // Write 0
            delay_us(45);            
            SETBIT(PORTA,0);
            delay_us(2);                         
        }
    }
}
//start conver temperature
void start1820 (void)       // ds1820 start convert
{               
    res1820 ();
    check1820 ();
    //delay_ms(1);
    write1820byte (0xcc);                    // skip rom
    write1820byte (0x44);                    // convert
}                           
//read temperature from1820 
//TH,high 4 bit of temperature
//TL,low 8 bit of temperature
void read1820 (unsigned char *TH,unsigned char *TL)     // read temp
{                
    res1820 ();
    check1820 ();
    //delay_ms(1);
    write1820byte (0xcc);                    // skip rom
    write1820byte (0xbe);                    // convert
    *TL=read1820byte();                    // LSB
    *TH=read1820byte();                    // MSB
}
//x^y function,do not beyond the range!
long pow(unsigned char x,unsigned char y)
{
    long ans;
    unsigned char i;
 ans=x;
 if(y==0)return 1;
 for(i=0;i<y-1;i++)ans*=x;
 return ans;
}
//get data from 1820
//p memory the temperature(bin 11 bit) 
void get1820data(unsigned char *p)
{
    unsigned char j,temp;
    unsigned char *TL,*TH;
    start1820 ();                    // ds1820 start convert
    read1820 (TH,TL);                // read temperature 
    for(j=1;j<=8;j++)
    {
        temp=*TL&0x01;
        *TL=*TL>>1;
        p[j-1]=temp;
    }   
    for(j=1;j<=3;j++)
    {
        temp=*TH&0x01;
        *TH=*TH>>1;
        p[j+7]=temp;
    }  
} 
void display(unsigned char number,unsigned char position)//digtial show function
{  
    DDRB=0Xff;//set PORTA output
 ORTB=0XFF;//set PORTB output in high level
    switch(position)//choice the position
 {
  case 1:{PORTB&=0xf8;break;}
  case 2:{PORTB&=0xf9;break;}
  case 3:{PORTB&=0Xfa;break;}
  case 4:{PORTB&=0Xfb;break;}
  case 5:{PORTB&=0Xfc;break;}
  case 6:{PORTB&=0Xfd;break;}
  case 7:{PORTB&=0Xfe;break;}
  case 8:{PORTB&=0Xff;break;}
  } 
    switch(number)//show number
 {
  case 0:{PORTB&=0x87;break;}    //0
  case 1:{PORTB&=0x8f;break;}    //1
  case 2:{PORTB&=0x97;break;}    //2
  case 3:{PORTB&=0x9f;break;}    //3
  case 4:{PORTB&=0xa7;break;}    //4
     case 5:{PORTB&=0xaf;break;}    //5
  case 6:{PORTB&=0xb7;break;}    //6
  case 7:{PORTB&=0xbf;break;}    //7
  case 8:{PORTB&=0xc7;break;}    //8
     case 9:{PORTB&=0xcf;break;}    //9
     default:{PORTB=0xff;break;}    //null
 }       
}

void main()
{
    unsigned char  p[11];
 uchar j;
 long t;
 unsigned char b1,b2,b3,b4,b5,b6,b7,bj;
    while(1)
 {
   b1=t%10;display(b1,8);delay_ms(3);
  b2=(t/10)%10;display(b2,7);delay_ms(3);
  b3=(t/100)%10;display(b3,6);delay_ms(3);
  b4=(t/1000)%10;display(b4,5);delay_ms(3);
  b5=(t/10000)%10;display(b5,4);CLRBIT(PORTB,7);delay_ms(3);SETBIT(PORTB,7);
        b6=(t/100000)%10;display(b6,3);delay_ms(3);
        b7=(t/1000000)%10;display(b7,2);delay_ms(3);
  if(bj<80)delay_ms(3);
  else
  {
             get1820data(p);
   t=0;
   for(j=0;j<11;j++)
   {
       t+=p[j]*pow(2,j); 
   }
   t*=625;
   bj=0;
  } 
  bj++;
    }
}