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#include <reg52.H>
#include <intrins.H>
#include <math.H>
#define uchar unsigned char
#define uint unsigned int
sbit rw = P3^6;
sbit RS = P3^5;
sbit LCDEN = P3^4;
sbit ds = P1^0; //溫度IO口定義
void delayUs()
{
_nop_();
}
void delayMs(uint a)
{
uint i, j;
for(i = a; i > 0; i--)
for(j = 100; j > 0; j--);
}
void writeComm(uchar comm)
{
RS = 0;
P2 = comm; //將要寫的命令送到數據總線
LCDEN = 1; //使能
delayUs();
LCDEN = 0;
delayMs(1);
}
//寫數據:RS=1, RW=0;
void writeData(uchar dat)
{
RS = 1;
P2 = dat;
LCDEN = 1;
delayUs();
LCDEN = 0;
delayMs(1);
}
void init()
{
rw = 0;
writeComm(0x38);
writeComm(0x0c);
writeComm(0x06);
writeComm(0x01);
}
void writeString(uchar * str, uchar length)
{
uchar i;
for(i = 0; i < length; i++)
{
writeData(str[i]);
}
}
/**//*****************************DS18B20*******************************/
void dsInit() //復位DS18B20初始化函數
{
unsigned int i;
ds = 0;
i = 100;
while(i>0) i--;
ds = 1;
i = 4;
while(i>0) i--;
}
void dsWait()
{
unsigned int i;
while(ds);
while(~ds);
i = 4;
while(i > 0) i--;
}
bit readBit()
{
unsigned int i;
bit b;
ds = 0;
i++;
ds = 1;
i++; i++;
b = ds;
i = 8;
while(i>0) i--;
return b;
}
unsigned char readByte()
{
unsigned int i;
unsigned char j, dat;
dat = 0;
for(i=0; i<8; i++)
{
j = readBit();
dat = (j << 7) | (dat >> 1);
}
return dat;
}
void writeByte(unsigned char dat) //向DS18B20寫一個字節的函數
{
unsigned int i;
unsigned char j;
bit b;
for(j = 0; j < 8; j++)
{
b = dat & 0x01;
dat >>= 1;
if(b) //寫1
{
ds = 0; i++; i++;
ds = 1;
i = 8; while(i>0) i--;
}
else
{
ds = 0; //寫0
i = 8; while(i>0) i--;
ds = 1;
i++; i++;
}
}
}
void sendChangeCmd() //DS18B20開始獲取溫度并轉換
{
dsInit();
dsWait();
delayMs(1);
writeByte(0xcc);
writeByte(0x44);
}
void sendReadCmd()
{
dsInit();
dsWait();
delayMs(1);
writeByte(0xcc);
writeByte(0xbe);
}
int getTmpValue() //讀取寄存器中的溫度數據
{
unsigned int tmpvalue;
int value;
float t;
unsigned char low, high;
sendReadCmd();
low = readByte(); //讀低8位
high = readByte(); //讀高8位
tmpvalue = high;
tmpvalue <<= 8; //兩個字節組合為一個字節
tmpvalue |= low;
value = tmpvalue;
t = value * 0.0625;
value = t * 100 + (value > 0 ? 0.5 : -0.5); //大于0加0.5, 小于0減0.5
return value;
}
void display(int v) //顯示溫度值函數
{
unsigned char count;
unsigned char datas[] = {0, 0, 0, 0, 0};
unsigned int tmp = abs(v);
datas[0] = tmp / 10000;
datas[1] = tmp % 10000 / 1000;
datas[2] = tmp % 1000 / 100;
datas[3] = tmp % 100 / 10;
datas[4] = tmp % 10;
writeComm(0xc0+3);
if(v < 0)
{
writeString("- ", 2);
}
else
{
writeString("+ ", 2);
}
if(datas[0] != 0)
{
writeData('0'+datas[0]);
}
for(count = 1; count != 5; count++)
{
writeData('0'+datas[count]);
if(count == 2)
{
writeData('.');
}
}
}
/**//*****************************DS18B20*******************************/
void main()
{
uchar table[] = " xianzaiwendu: ";
sendChangeCmd();
init();
writeComm(0x80);
writeString(table, 16);
while(1)
{
delayMs(1000); //溫度轉換時間需要750ms以上
writeComm(0xc0);
display(getTmpValue());
sendChangeCmd();
}
}
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