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標題: DS18B20溫度傳感器報警 [打印本頁]

作者: wangchengg 時間: 2018-7-27 18:51
標題: DS18B20溫度傳感器報警
#include<reg52.h>
#include<intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit ds = P2^2;
sbit dula = P2^6;
sbit wela = P2^7;
sbit beep = P2^3;
bit flag;
uint temp;
uchar code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,
0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
uchar code table1[]={0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,
0x87,0xff,0xef};
void TempDelay(uchar us)
{
while(us--); //6.51us
}
void delay(int z)
{
uint x,y;
for(x=z;x>0;x--)
  for(y=115;y>0;y--);
}
void display(uint temp)
{
uchar bai,shi,ge;
bai=temp/100;
shi=temp%100/10;
ge=temp%100%10;
dula=1;
P0=table[bai];
dula=0;
P0=0xff;
wela=1;
P0=0xfe;
wela=0;
delay(3);
dula=1;
P0=table1[shi];
dula=0;
P0=0xff;
wela=1;
P0=0xfd;
wela=0;
delay(3);
dula=1;
P0=table[ge];
dula=0;
P0=0xff;
wela=1;
P0=0xfb;
wela=0;
delay(3);
}
void ds_reset()
{
ds=1;
_nop_();
ds=0;
TempDelay(80);//520us
ds=1;
TempDelay(5);
if(ds==0)
  flag=1;
else
  flag=0;
TempDelay(20);
ds=1;
}
bit ds_read_bit()
{
bit dat;
ds=0;
_nop_();
_nop_();
ds=1;
_nop_();
dat=ds;
TempDelay(12);
return dat;
}
uchar ds_read_byte()
{
uchar i,j,value;
for(i=0;i<8;i++)
{
  j=ds_read_bit();
  value=(j<<7)|(value>>1);
}
return value;
}
void ds_write_byte(uchar dat)
{
uchar i,onebit;
for(i=0;i<8;i++)
{
  onebit=dat&0x01;
  if(onebit) //寫1
  {
ds=0;
TempDelay(1);
ds=1;
_nop_();
  }
  else  //寫0
  {
ds=0;
TempDelay(11);
ds=1;
_nop_();
  }
  dat>>=1;
}
}
void ds_change()
{
ds_reset();
ds_write_byte(0xcc);
ds_write_byte(0x44);
}
uint get_temperature()
{
uchar a,b;
float temperature;
ds_reset();
ds_write_byte(0xcc);
ds_write_byte(0xbe);
a=ds_read_byte();
b=ds_read_byte();
temp=b;
temp<<=8;
temp|=a;
temperature=temp*0.0625;
temp=temperature*10+0.5;
return temp;
}
void main()
{
ds_change();
delay(1000);
while(1)
{
  display(get_temperature());
  ds_change();
  if(get_temperature()>350)//35度蜂鳴器發聲
beep=0;
  else
beep=1;
}
}

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