CEPARK 51 MCU DS18B20 test program

/**********************************************************************
* File name: CEPARK 51 V2.0 development board
* Program version: V1.0
* Technical support: http://bbs.cepark.com

*CEPARK 
http://bbs.cepark.com/viewthread.php?tid=34&fromuid=6136

* Cepark summer 51 free online training program---activity registration address:
http://bbs.cepark.com/viewthread.php?tid=14228&fromuid=6136
**********************************************************************/
#include "STC89C51RC_RD_PLUS.H"

#define uchar unsigned char
#define uint unsigned int

uchar code C51BOX2[3] _at_ 0x43; //The emulator uses three bytes of space

uchar code DispTab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,
                      0x88,0x83,0xc6,0xa1,0x86,0x8e}; //Segment code 0-9,af
uchar DispBuf[4];

uchar TempH,TempL;
uint Temp;
bit Presence;

sfr LedPort=0x80; //P0 port segment code
sbit Led0 = P1^0; //LED control pin
sbit Led1 = P1^1;
sbit Led2 = P1^2;
sbit Led3 = P1^3;
sbit DataPort=P1^6; //18B20 data port

void uDelay(uchar DelayTime) //Delay subroutine, each increase of 1 in the entry parameter adds about 2us
{ while(--DelayTime);

}

void Hex2Bcd() //HEX to BCD program
{
    if(Presence==1)
        { //If no existence is detected, display "no"
        DispBuf[0]=0xab;
        DispBuf[1]=0xa3;
        DispBuf[2]=0xff;
        DispBuf[3]=0xff;
        }
    else
        { //After decomposition, look up the table to get the segment code and put it into the display buffer
        Temp=TempH*256+TempL; //Merge the data into a double-byte numberif

        ((Temp>>12)==0xf) //Shift right 12 bits to determine whether it is a negative temperature
            {Temp=0x10000-Temp; //Calculate the negative temperature valueDispBuf
            [0]=0xbf;} //And display the "-" sign on the leftmost digital tubeelse
        DispBuf[0]=0xff; //Otherwise, do not display

        TempH=Temp>>4; //After removing the 4-digit decimal point, get the integer part and put it in TempH
        Temp=(Temp&0x0f)*625; //AND out the 4-digit decimal point, and get the decimal point value by multiplication
        DispBuf[3]=DispTab[Temp/1000]; //Only the highest digit of the decimal point is taken, and the last three digits are not displayed

        DispBuf[2]=DispTab[TempH%10]&0x7f; //Process the ones digit and light up the decimal point
        TempH=TempH/10; //Get the hundreds and tens digits

        if(!TempH) DispBuf[1]=0xff;//If the hundreds and tens digits are both 0, the tens digit will not be displayed.
            else DispBuf[1]=DispTab[TempH%10];

        if(DispBuf[0]==0xff)//Positive temperature condition
            {
            if(TempH/10) DispBuf[0]=DispTab[TempH/10];//Hundreds place has a value displayedelse
            DispBuf[0]=0xff;//No display if it is 0
            }
        }
}

void Display(uchar j) //Display subroutine
{
    for(;j>0;j--)
    {
        LedPort=DispBuf[0];
        Led0=0;
        uDelay(20);
        Led0=1;
        LedPort=DispBuf[1];
        Led1=0;
        uDelay(20);
        Led1=1;
        LedPort=DispBuf[2];
        Led2=0;
        uDelay(20);
        Led2=1;
        LedPort=DispBuf[3];
        Led3=0;
        uDelay(20);
        Led3=1;
    }
}

void Inti()
{
    DataPort=0; //Pull low
    uDelay(180); //Pull high after delay
    DataPort=1;
    uDelay(24); //Read status after delay, if exists, 18B20 will pull port low
    Presence=DataPort; //Save status for later display judgment
    uDelay(230); //Delay completes one cycle time
}

void WriteByte(uchar val) //Byte write
{
 uchar i;
  for (i=8; i>0; i--)
  {
    DataPort = 0;
    uDelay(4);
    DataPort = val&0x01;
    uDelay(20);
    DataPort = 1;
    val=val/2;
  }
  uDelay(50);
}


uchar ReadByte() //Byte read
{
uchar i;
uchar value=0;
    for (i=0;i<8;i++)//Read 8 bytes
    {
        DataPort=0; //Pull low and then high to generate a read gapDataPort
        =1;
        uDelay(4); //Read after delayif
        (DataPort) value|=0x01<         uDelay(20); //Delay completes one cycle time
    }
return (value);
}

void SetStep(uchar Dat) //Entry parameters, 1F-0.5 degree step, 3F-0.25 degree, 5F-0.125 degree, 7F-0.0625 degree
{
    Inti();
    WriteByte(0xcc);
    WriteByte(0x4e);
    WriteByte(0x15); //Write address 2—TH
    WriteByte(0x00); //Write address 3—TL
    WriteByte(Dat); //Address 4, reserved area, used for decimal resolution, 1F, 3F, 5F, 7F values, the larger the value, the higher the resolution
    Inti();
    WriteByte(0xcc);
    WriteByte(0xbe);
    ReadByte();
    Inti();
    WriteByte(0xcc);
    WriteByte(0x48); //Copy instruction, wait 6ms after sending it, wait for 18B20 to write data into EEPROM, reset after writing is completed.
    uDelay(100);
    Inti();
    DataPort=1;
}

void GetTemp() //Temperature acquisition subroutine, return value is in TempH, TempL
{
    Inti(); Display(8); //Add display each time an instruction is executed to eliminate flicker
    WriteByte(0xcc); Display(8);
    WriteByte(0x44); Display(8);
    Inti(); Display(8);
    WriteByte(0xcc); Display(8);
    WriteByte(0xbe); Display(8);
    TempL=ReadByte(); Display(8);
    TempH=ReadByte(); Display(8);
}

void main(void)
{
    uDelay(100);
    Presence=1;
    SetStep(0x7f);
    GetTemp();Display(100); //After sending the first temperature acquisition instruction, it takes a while to wait for the internal conversion. (Solve the problem of 85 degrees display when booting.)
    while(1){GetTemp();Hex2Bcd();Display(50);}

}