#include <avr/io.h>
#include <util/delay.h>
#define uchar unsigned char
#define uint unsigned int
#define BUS PORTC
// Low level port/pin definitions 低级端口/引脚定义
#define sbit(x,PORT) (PORT) |= (1<<x)
#define cbit(x,PORT) (PORT) &= ~(1<<x)
#define pin(x,PIN) (PIN) & (1<<x)
// Pins definition 引脚定义
#define s_digit1 sbit(5,PORTC)
#define c_digit1 cbit(5,PORTC)
#define s_digit2 sbit(4,PORTC)
#define c_digit2 cbit(4,PORTC)
#define out PORTC
#define DQ_IN DDRA&=~(1<<7)
#define DQ_OUT DDRA|=(1<<7)
#define S_DQ sbit(7,PORTA)
#define C_DQ cbit(7,PORTA)
#define DQ pin(7,PINA)
// Function Prototypes 函数原型
void init_ds18b20(void);
uchar readbyte(void);
void writecommand(uchar);
uchar readtemp(void);
uchar a, b, tt;
// Main program 主函数
int main(void)
{ uchar i=0, temp;
// Initialize Stack Pointer 初始化堆栈指针
SPL=0x54;
SPH=0x04;
// Configure port pins 配置端口引脚
DDRC = 0xff;
DDRA = 0xff;
while(1)
{ temp = readtemp();
for(i=0; i<10; i++) // 10 measures
{ // output the units 输出的单位
out = (temp/10) & 0x0f;
s_digit1;
c_digit2;
_delay_ms(5);
// output the tens 输出十
out = (temp%10) & 0x0f;
c_digit1;
s_digit2;
_delay_ms(5);
}
}
}
// Start transaction with 1-wire line. 用单线启动事务
void init_ds18b20(void)
{ DQ_OUT;
C_DQ ;
_delay_us(600);
S_DQ;
_delay_us(50);
DQ_IN;
while(DQ);
_delay_us(240);
DQ_OUT;
S_DQ;
_delay_us(300);
}
// Read a byte from the sensor 从传感器读取一个字节
uchar readbyte(void)
{ uchar i = 0,data = 0;
DQ_OUT;
for (i=0; i<8; i++)
{ C_DQ ;
data >>= 1;
_delay_us(3);
S_DQ;
DQ_IN;
_delay_us(12);
if(DQ)
data |= 0x80;
DQ_OUT;
S_DQ;
_delay_us(45);
_delay_us(5);
}
return(data);
}
// Write a command to the sensor 向传感器写入命令
void writecommand(uchar data)
{ uchar i;
for(i=0; i<8; i++)
{ C_DQ;
_delay_us(15);
if(data & 0x01)
S_DQ;
else
C_DQ;
_delay_us(45);
data >>= 1;
S_DQ;
_delay_us(2);
}
}
// Read value from the sensor 从传感器读取值
uchar readtemp(void)
{ uint t;
init_ds18b20();
// Convert 转换
writecommand(0xCC);
writecommand(0x44);
init_ds18b20();
// Read Scratch memory area 读暂存区
writecommand(0xCC);
writecommand(0xBE);
a = readbyte();
b = readbyte();
t = b;
t <<= 8;
t = t|a;
tt = t*0.0625;
return(tt);
} |
QQ好友和群
QQ空间
腾讯微博
腾讯朋友
收藏
淘帖
顶
踩
