代码如下
#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
sbit DQ=P2^7;
sbit led=P1^0;
sbit rs=P2^0;
sbit rw=P2^1;
sbit e=P2^2;
uchar temp,temp1;
void delay(uint t);
void delay_1ms(uint z);
uchar init_ds18b20();
void write_byte(uchar dat);
uchar read_byte(void);
uchar read_tem(void);
void write_com(uchar com);
void write_dat(uchar dat);
void init();
void main()
{ unsigned char n;
init();
while(1)
{
temp=read_tem(); //温度值的整数部分
n=init_ds18b20();
if(n)
led=0;
write_com(0x80+8);
write_dat(0xdf); //显示温度符号
write_dat(0x43); //显示温度符号
delay_1ms(5);
write_com(0x80+1);
write_dat(0x30+temp/10); //显示温度的十位
write_dat(0x30+temp%10); //显示温度的个位
write_com(0x80+4);
write_dat('.');
write_dat(0x30+temp1); //显示小数部分
}
}
void delay_1ms(uint z) //
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
void delay(uint t)
{
while(t--);
}
uchar init_ds18b20()
{
uchar n;
DQ=1;
delay(8);
DQ=0;
delay(80);//600us
DQ=1;
delay(8);//15us~60us
n=DQ;
delay(4);
return 0;
}
void write_byte(uchar dat)
{
uchar i;
for(i=0;i<8;i++)
{
DQ=0;
DQ=dat&0x01;
delay(4);
DQ=1;
dat=dat>>1;
}
delay(4);
}
uchar read_byte(void)
{
uchar i,value;
for(i=0;i<8;i++)
{
DQ=0;
value>>=1;
DQ=1; //
if(DQ)
value|=0x80;
delay(4);
}
return value;
}
uchar read_tem(void)
{
uchar a,b,temp0;
init_ds18b20();
write_byte(0xcc);//ì?1yROM
write_byte(0x44);//???ˉ???è2aá?
delay(300);
init_ds18b20();
write_byte(0xcc);
write_byte(0xbe);//?á???è
a=read_byte();
b=read_byte();
b<<=4;
temp1=(a&0x0f);
temp1=temp1*0.625+0.5;
a>>=4;
temp0=b|a;
return temp0;
}
void write_com(uchar com)
{
rs=0;
rw=0;
P1=com;
e=1;
delay_1ms(5);//?T?óê±2??ü?y3￡1¤×÷
e=0;
}
void write_dat(uchar dat)
{
rs=1;//????D′êy?Y
rw=0;
P1=dat;
e=1;
delay_1ms(5);//
e=0;
}
void init() //
{
delay_1ms(15);
write_com(0x38);
delay_1ms(6);
write_com(0x38);
delay_1ms(6);
write_com(0x38);
write_com(0x38);
write_com(0x0c);
write_com(0x06);
write_com(0x01);
}
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