77 lines
1.3 KiB
C
77 lines
1.3 KiB
C
|
#include "onewire.h"
|
|||
|
|
#include "reg52.h"
|
|||
|
|
|
|||
|
|
sbit DQ = P1 ^ 4;
|
|||
|
|
|
|||
|
|
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><DAB2><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>
|
|||
|
|
void Delay_OneWire(unsigned int t)
|
|||
|
|
{
|
|||
|
|
t *= 12;
|
|||
|
|
while (t--)
|
|||
|
|
;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><D0B4><EFBFBD><EFBFBD>
|
|||
|
|
void Write_DS18B20(unsigned char dat)
|
|||
|
|
{
|
|||
|
|
unsigned char i;
|
|||
|
|
for (i = 0; i < 8; i++)
|
|||
|
|
{
|
|||
|
|
DQ = 0;
|
|||
|
|
DQ = dat & 0x01;
|
|||
|
|
Delay_OneWire(5);
|
|||
|
|
DQ = 1;
|
|||
|
|
dat >>= 1; // һ<><D2BB>һ<EFBFBD><D2BB>д<EFBFBD><D0B4>
|
|||
|
|
}
|
|||
|
|
Delay_OneWire(5);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// <20><><EFBFBD><EFBFBD><EFBFBD>߶<EFBFBD><DFB6><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
|
unsigned char Read_DS18B20(void)
|
|||
|
|
{
|
|||
|
|
unsigned char i;
|
|||
|
|
unsigned char dat;
|
|||
|
|
|
|||
|
|
for (i = 0; i < 8; i++)
|
|||
|
|
{
|
|||
|
|
DQ = 0;
|
|||
|
|
dat >>= 1;
|
|||
|
|
DQ = 1;
|
|||
|
|
if (DQ)
|
|||
|
|
{
|
|||
|
|
dat |= 0x80; // һ<><D2BB>һ<EFBFBD><D2BB><EFBFBD><EFBFBD>ȡ
|
|||
|
|
}
|
|||
|
|
Delay_OneWire(5);
|
|||
|
|
}
|
|||
|
|
return dat;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// DS18B20<32><30>ʼ<EFBFBD><CABC>
|
|||
|
|
bit init_ds18b20(void)
|
|||
|
|
{
|
|||
|
|
bit initflag = 0;
|
|||
|
|
|
|||
|
|
DQ = 1;
|
|||
|
|
Delay_OneWire(12);
|
|||
|
|
DQ = 0;
|
|||
|
|
Delay_OneWire(80);
|
|||
|
|
DQ = 1;
|
|||
|
|
Delay_OneWire(10);
|
|||
|
|
initflag = DQ;
|
|||
|
|
Delay_OneWire(5);
|
|||
|
|
|
|||
|
|
return initflag;
|
|||
|
|
}
|
|||
|
|
float rd_temperature()
|
|||
|
|
{
|
|||
|
|
unsigned char low, high;
|
|||
|
|
init_ds18b20(); // <20><>ʼ<EFBFBD><CABC>
|
|||
|
|
Write_DS18B20(0xcc); // <20><><EFBFBD><EFBFBD>ROM
|
|||
|
|
Write_DS18B20(0x44); // <20><><EFBFBD><EFBFBD><EFBFBD>¶<EFBFBD>ת<EFBFBD><D7AA>
|
|||
|
|
init_ds18b20(); // <20><>ʼ<EFBFBD><CABC>
|
|||
|
|
Write_DS18B20(0xcc); // <20><><EFBFBD><EFBFBD>ROM
|
|||
|
|
Write_DS18B20(0xbe); // <20><>ȡ<EFBFBD>¶<EFBFBD>
|
|||
|
|
low = Read_DS18B20(); // <20><>λ
|
|||
|
|
high = Read_DS18B20(); // <20><>λ
|
|||
|
|
return ((high << 8) | low) / 16.0;
|
|||
|
|
}
|