DS18B20 temperature microcontroller control display C program

The c program is as follows:

#include

#define uchar unsigned char
#define uint unsigned int

sbit DQ=P3^7; //ds18b20 and microcontroller connection port
sbit RS=P3^0;
sbit RW=P3^1;
sbit EN=P3^2;

unsigned char code str1[]={"temperature: "};
unsigned char code str2[]={"              "};

uchar data disdata[5];
uint tvalue; //temperature value
uchar tflag; //temperature positive and negative flag

/*************************lcd1602 program******************************/
void delay1ms(unsigned int ms)//Delay 1 millisecond (not precise enough)
{unsigned int i,j;
   for(i=0;i     for(j=0;j<100;j++);
}

void wr_com(unsigned char com)// 写电影//
{ delay1ms(1);
   RS=0;
   RW=0;
   EN=0;
   P2=how;
   delay1ms(1);
   EN=1;
   delay1ms(1);
   EN=0;
}

void wr_dat(unsigned char dat)//写数据//
{ delay1ms(1);;
   RS=1;
   RW=0;
   EN=0;
   P2=dat;
   delay1ms(1);
   EN=1;
   delay1ms(1);
   EN=0;
}

void lcd_init()//initialization settings//
{delay1ms(15);
wr_com(0x38);delay1ms(5);
   wr_com(0x08);delay1ms(5);
    wr_com(0x01);delay1ms(5);
     wr_com(0x06);delay1ms(5);
      wr_com(0x0c);delay1ms(5);
}

void display(unsigned char *p)//显示//
{
while(*p!='\0')
{
wr_dat(*p);
p++;
delay1ms(1);
}
}

init_play()//Initialize display
{ lcd_init();
    wr_com(0x80);
display(str1);
wr_com(0xc0);
display(str2);
   }

/******************************ds1820 program*******************************************/
void delay_18B20(unsigned int i)//delay 1 microsecond
{
   while(i--);
}

void ds1820rst()/*ds1820 reset*/
{ unsigned char x=0;
DQ = 1; //DQ reset
delay_18B20(4); //delay
DQ = 0; //DQ pull low
delay_18B20(100); //accurate delay greater than 480us
DQ = 1; //pull high
delay_18B20(40); 
   } 

   uchar ds1820rd()/*read data*/
{ unsigned char i=0;
unsigned char dat = 0;
for (i=8;i>0;i--)
{ DQ = 0; //give pulse signal
    dat>>=1;
    DQ = 1; //give pulse signal
    if(DQ)
    dat|=0x80;
    delay_18B20(10);
}
   return(dat);
}

void ds1820wr(uchar wdata)/*写数据*/
{unsigned char i=0;
    for (i=8; i>0; i--)
   { DQ = 0;
     DQ = wdata&0x01;
     delay_18B20(10);
     DQ = 1;
     wdata>>=1;
   }
}
 

read_temp()/*read temperature value and convert*/
{uchar a,b;
ds1820rst();    
ds1820wr(0xcc);//*skip reading serial number*/
ds1820wr(0x44);//*start temperature conversion*/
ds1820rst();    
ds1820wr(0xcc);//*skip reading serial number*/ 
ds1820wr(0xbe);//*read temperature*/ 
a=ds1820rd();
b=ds1820rd();
tvalue=b;
tvalue<<=8;
tvalue=tvalue|a;
    if(tvalue<0x0fff)
   tflag=0;
    else
   {tvalue=~tvalue+1;
tflag=1;
   }
tvalue=tvalue*(0.625);//expand temperature value 10 times, accurate to 1 decimal place
return(tvalue);
}

/*******************************************************************/
   void ds1820disp()//temperature value display
{ uchar flagdat;
   disdata[0]=tvalue/1000+0x30;//hundreds digit
     disdata[1]=tvalue%1000/100+0x30;//ten digit
     disdata[2]=tvalue%100/10+0x30;//ones digit
     disdata[3]=tvalue%10+0x30;//decimal digitif
    
     (tflag==0)
     flagdat=0x20;//positive temperature does not display a signelse
     flagdat
       =0x2d;//negative temperature displays a minus sign:-

     if(disdata[0]==0x30)
    {disdata[0]=0x20; //If the hundreds digit is 0, it will not be displayed
   if(disdata[1]==0x30)
    {disdata[1]=0x20; //If the hundreds digit is 0, the tens digit will not be displayed either
    }
   }

    wr_com(0xc0);
   wr_dat(flagdat);//display the sign bit
    wr_com(0xc1);
    wr_dat(disdata[0]);//display the hundreds digit
    wr_com(0xc2);
    wr_dat(disdata[1]);//display the tens digit 
    wr_com(0xc3);
    wr_dat(disdata[2]);//display the ones digit 
    wr_com(0xc4);
    wr_dat(0x2e);//display the decimal point 
    wr_com(0xc5);
    wr_dat(disdata[3]);//display the decimal place
   }
/********************Main program***********************************/
void main()
{ init_play();//initialize the display
   while(1)
{read_temp();//read the temperature
    ds1820disp();//display
}
}