DS18B20测负温度程序
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//main.c
#include
#include
#include "18B20.h"
#include"disp.h"
#define uint unsigned int
#define uchar unsigned char
const uchar shu[10]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,
0x82,0xF8,0x80,0x90};
const uchar bshu[3]={0xff,0xf9,0xbf};
//延时函数在4M时延时1ms
void s_1ms(unsigned int ms)
{
unsigned int aa;
for(;ms>=1;ms--)
{
for(aa=0;aa<=800;aa++)
{;}
}
}
void main()
{
uint wendu,xiao,ge,shi,bai;
uchar fh;
DDRA = 0xff;
PORTA = 0xff;
s_1ms(200); //延时200ms
ds1820_reset(); //DS18B20复位
while (1)
{
ds1820_start();
wendu = ds1820_read_temp(); //读取温度数值
fh=ds1820_fh();
if(fh)
{
wendu=~(wendu)+1;
wendu = (wendu * 10)/ 16; //数值处理
wendu = wendu % 1000;
shi= wendu / 100; //显示第2位
wendu = wendu % 100;
ge= wendu / 10; //显示ge位
xiao=wendu % 10; // 显示小数位
display(0,shu[xiao]); //小数位
display(1,shu[ge]&0x7f); //个位
display(2,shu[shi]); //shi
display(3,bshu[2]); //bai位,0不显示
}
else
{
wendu = (wendu * 10) / 16; //数值处理
bai = wendu / 1000; //bai位
wendu = wendu % 1000;
shi= wendu / 100; //显示第2位
wendu = wendu % 100;
ge= wendu / 10; //显示ge位
xiao=wendu % 10; // 显示小数位
display(0,shu[xiao]); //小数位
display(1,shu[ge]&0x7f); //个位
display(2,shu[shi]); //shi
display(3,bshu[bai]); //bai位,0不显示
}
}
}
//18B20.h
#define uchar unsigned char
#define uint unsigned int
//设置成输入
#define DQ_INPUT DDRC &= ~BIT(7)
//设置成输出
#define DQ_OUT DDRC |= BIT(7)
//设置成低电平
#define DQ_LO PORTC &= ~BIT(7)
//设置成高电平
#define DQ_HI PORTC |= BIT(7)
//读出
#define DQ_R PINC & BIT(7)
//中断标志
uchar init_f;
//延时函数
void delay_us(uint ms)
{
uchar tm;
while(ms--)
{
for(tm=0;tm<2;tm++);
}
}
//DS18B20复位
void ds1820_reset(void)
{
uchar i;
//中断保护
init_f = SREG;
//关中断
CLI();
DQ_OUT;
DQ_LO;
delay_us(80); //延时500us
DQ_HI;
DQ_INPUT;
delay_us(10); //延时80us
i = DQ_R;
delay_us(80); //延时500us
if (init_f & 0x80) //恢复中断状态
{
SEI();
}
}
//DS18B20字节读取
uchar ds1820_read_byte(void)
{
uchar i;
uchar value = 0;
//中断保护
init_f = SREG;
//关中断
CLI();
for (i = 8; i != 0; i--) {
value >>= 1;
DQ_OUT;
DQ_LO;
delay_us(2);
DQ_HI;
DQ_INPUT;
if (DQ_R)
{
value|=0x80;
}
delay_us(10); //延时60us
}
if (init_f&&0x80) //恢复中断状态
{
SEI();
}
return(value);
}
//DS18B20字节写入
void ds1820_write_byte(unsigned char value)
{
uchar i;
init_f = SREG;
CLI();
for (i = 8; i > 0; i--)
{
DQ_OUT;
DQ_LO;
if (value & 0x01)
{
DQ_HI;
}
delay_us(10); //延时80us
DQ_HI;
value >>= 1;
}
if (init_f & 0x80)//恢复中断状态
{
SEI();
}
}
//启动ds1820转换
void ds1820_start(void)
{
ds1820_reset();
ds1820_write_byte(0xCC); //勿略ROM
ds1820_write_byte(0x44); //启动转换
}
//读温度
uint ds1820_read_temp(void)
{
uint i,wendu;
uchar buf[2];
ds1820_reset();
ds1820_write_byte(0xCC); //勿略ROM
ds1820_write_byte(0xBE); //读温度
for (i = 0; i < 2; i++)
{
buf[i] = ds1820_read_byte();
}
wendu = (buf[1]<<8)|buf[0];
return wendu;
}
uint ds1820_fh(void) //读正负温度符号
{
uint i,bb;
uchar buf[2];
ds1820_reset();
ds1820_write_byte(0xCC); //勿略ROM
ds1820_write_byte(0xBE); //读温度
for (i = 0; i < 2; i++)
{
buf[i] = ds1820_read_byte();
}
bb=buf[1]&0xf0;
return bb;
}
//disp.h
#define uchar unsigned char
#define uint unsigned int
#define SHCP_0 PORTA&=~BIT(1)
#define SHCP_1 PORTA|=BIT(1)
#define DS_0 PORTA&=~BIT(3)
#define DS_1 PORTA|=BIT(3)
#define STCP_0 PORTA&=~BIT(2)
#define STCP_1 PORTA|=BIT(2)
void CKin()
{
SHCP_0;
NOP();
SHCP_1;
}
void Dataout() //并行输出
{
STCP_0;
NOP();
STCP_1;
}
void Datein( uchar date ) //数据串行输入
{
uchar i,mod;
DDRA=0xff;
for(i=0;i<8;i++)
{
mod=date&0x80;
if(mod==0x80)
{DS_1;}
else
{DS_0;}
CKin();
date<<=1;
}
Dataout(); //并行输出
}
void weihao(uchar add)
{
DDRA=0xff;
switch(add)
{
case 0:PORTA=0x1f;break;
case 1:PORTA=0x1f|0x80;break;
case 2:PORTA=0x1f|0x40;break;
case 3:PORTA=0x1f|0xc0;break;
case 4:PORTA=0x1f|0x20;break;
case 5:PORTA=0x1f|0xA0;break;
case 6:PORTA=0x1f|0x60;break;
case 7:PORTA=0x1f|0xE0;break;
default:break;
}
}
void DELAY(uint tt)
{
uint mm;
while(tt--)
{
for(mm=30;mm>0;mm--);
}
}
void display(uchar wei,uchar data)
{
weihao(wei);
Datein(data);
DELAY(20);
weihao(wei);
Datein(0xff);
}
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