ds18b20_c51.c

分布式系统中单片机用DS18B20采集温度的程序

      #include <reg51.h>
       #define uchar unsigned char
       uchar bdata write_char;
       uchar bdata read_char;
       sbit read_b=read_char^7;
       sbit write_b=write_char^0;
       uchar ds1820[9];//存放从DS18B20读取的9字节数据
       uchar rom_code[8];//存放DS18B20的64位序列号
       uchar i,crc; 
       uchar dot;
       const uchar led_code[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};//存放LED的显示码
       uchar LED[5]={0x3f,0x3f,0x3f,0x3f,0x3f};
       sbit DQ=P1^0;
       sbit PSW_5=PSW^5;    
        unsigned int ds1820_temp;//存放温度读数   
        uchar *asc2p;
      uchar shift;
	  int kk=0,initnum;
	  sbit p00=P0^1;
void delay15u(int x)
{
        uchar data i=1;

       while(--x){while(i!=0)i--;}
}

void reset_1820()
{
        DQ=0;delay15u(32);DQ=1;
        delay15u(4);PSW_5=0;
        if(DQ==0)PSW_5=1;
}


void LED_write(uchar tem)
{ 
 
 
 P2=tem;//输出
}

void write_1820(uchar x)
{
 uchar i;

 write_char=x;
        for(i=0;i<8;i++){
           DQ=0;delay15u(1);DQ=write_b;
           write_char>>=1;delay15u(1);
           DQ=1;       
           }    
}


void start_convert()
{
        

        initnum=0;PSW_5=0;
        while(!PSW_5&&initnum++<10)reset_1820();if(initnum>10)return;
        delay15u(256);write_1820(0xcc);write_1820(0x44);
}




int read_1820()
{
 uchar i;

       
                for(i=0;i<8;i++){
                        DQ=0;DQ=1;
                        delay15u(1);
                        read_char>>=1;read_b=DQ;DQ=1;
                        }
                
         return read_char;     
               
}
void get_temperature()
{
        int i;

       for(i=0;i<9;i++)ds1820[i]=0x00;
        while(DQ!=1)initnum=0;PSW_5=0;
        while(!PSW_5&&initnum++<10)reset_1820();if(initnum>9)return;
        delay15u(256);write_1820(0xcc);write_1820(0xbe);
		 for (i=0;i<9;i++)
         {
		  ds1820[i]=read_1820();
		 }
        reset_1820();
		
}
 void ds1820_match(unsigned char *p)
  {
   unsigned char i;
   
   reset_1820();
   write_1820(0x55);	 
   for(i=0;i<8;i++)
     write_1820(p[i]);
}                       

unsigned char crccheck(unsigned char *p,unsigned char len)
{
unsigned char bit0,cbit,r,temp,i,j,byte;
temp=0;
for (j=0;j<len;j++)
   {
    byte=p[j];
    for(i=0;i<8;i++)
        {
        cbit=temp&0x01;
        bit0=byte&0x01;
        temp=temp>>1;
        r=cbit^bit0;
        if(r==1)
           temp=temp^0x8c;
        byte=byte>>1;
        }
    }
return temp;	
}

void delay_ms(int time)
 {     
 do
	{
	delay15u(70);time--;
	}	
  while (time>1);
  
	}

void asc2con(unsigned char *p)
{
  unsigned char temp;
  
  temp=p[1]&0xf0;temp=temp>>4;
  LED[1]=led_code[temp];
  temp=p[1]&0x0f;
  LED[2]=led_code[temp];
   temp=p[2]&0xf0;
  temp=temp>>4;
  LED[3]=led_code[temp];
  temp=p[2]&0x0f;
  LED[4]=led_code[temp];
  delay_ms(2000);
  
  temp=p[3]&0xf0;
  temp=temp>>4;
  LED[1]=led_code[temp];
  temp=p[3]&0x0f;
  LED[2]=led_code[temp];
   temp=p[4]&0xf0;
  temp=temp>>4;
  LED[3]=led_code[temp];
  temp=p[4]&0x0f;
  LED[4]=led_code[temp];
  delay_ms(2000);

   
temp=p[5]&0xf0;
  temp=temp>>4;
  LED[1]=led_code[temp];
  temp=p[5]&0x0f;
  LED[2]=led_code[temp];
   temp=p[6]&0xf0;
  temp=temp>>4;
  LED[3]=led_code[temp];
  temp=p[6]&0x0f;
  LED[4]=led_code[temp];
delay_ms(2000);

}
void service2(void) interrupt 3
{kk=kk%5;
shift=(1<<kk);
  P0=0xff-shift;
LED_write(LED[kk]);
kk++;
}
void main(void)
{

TMOD=0x20;
TL1=0x00;   //波特率为9600  
TH1=0x00;
LED[0]=0x3f;
LED[1]=0x06;
LED[2]=0x5b;
LED[3]=0x4f;
LED[4]=0x66;
TR1=1;
IE=0X88;
delay_ms(1000); 
write_1820(0x33);
for (i=0;i<8;i++)
  {
  rom_code[i]=read_1820();//读出64位序列号
  }
asc2p=&rom_code[0];
  crc=crccheck(asc2p,8); //计算CRC校验和
 asc2p=&rom_code[0];
	asc2con(asc2p); 
  delay_ms(4000); //延时
  if (crc==0x00)    //CRC校验正确，显示序列号
     {
   asc2p=&rom_code[0];
	asc2con(asc2p); 
	delay_ms(1000); //延时
     }

start_convert();
get_temperature();

    /* asc2p=&rom_code[0];
     ds1820_match(asc2p);//匹配DS182
     write_1820(0x44); //启动DS1820转换
     delay_ms(1000); //延时ms
     write_1820(0xbe); //读转换后温度