返回的值,已经是温度的16进制形式
假如 返回值为 0x1504 那么温度即 21.4。 0x15=16+5=21 0x04=4 21.4 ℃。
程序调用方法:
int main(void)
{
unsigned int value;
ds18b20_init();
while(1)
{
value = ds18b20_read();
}
}
下载链接:http://download.csdn.net/detail/u014357799/8900409
DS18B20.h:
#ifndef __DS18B20_H__
#define __DS18B20_H__
#include "stm32f4xx_hal.h"
#define SkipROM 0xCC //
#define SearchROM 0xF0 //
#define ReadROM 0x33 //
#define MatchROM 0x55 //
#define AlarmROM 0xEC //
#define StartConvert 0x44 //
#define ReadScratchpad 0xBE //
#define WriteScratchpad 0x4E //
#define CopyScratchpad 0x48 //
#define RecallEEPROM 0xB8 //
#define ReadPower 0xB4 //
void ds18b20_init(void);
unsigned short ds18b20_read(void);
#endif
DS18B20.c:
#include "ds18b20.h"
#define EnableINT()
#define DisableINT()
#define DS_PORT GPIOA
#define DS_DQIO GPIO_PIN_1
#define DS_RCC_PORT RCC_APB2Periph_GPIOA
#define DS_PRECISION 0x7f //??????? 1f=9?; 3f=10?; 5f=11?; 7f=12?;
#define DS_AlarmTH 0x64
#define DS_AlarmTL 0x8a
#define DS_CONVERT_TICK 1000
#define ResetDQ() HAL_GPIO_WritePin(DS_PORT,DS_DQIO,GPIO_PIN_RESET)
#define SetDQ() HAL_GPIO_WritePin(DS_PORT,DS_DQIO,GPIO_PIN_SET)
#define GetDQ() HAL_GPIO_ReadPin(DS_PORT,DS_DQIO)
static unsigned char TempX_TAB[16]={0x00,0x01,0x01,0x02,0x03,0x03,0x04,0x04,0x05,0x06,0x06,0x07,0x08,0x08,0x09,0x09};
void Delay_us(uint32_t Nus)
{
uint32_t i;
i = Nus * 168;
while(i--);
}
unsigned char ResetDS18B20(void)
{
unsigned char resport;
SetDQ();
Delay_us(50);
ResetDQ();
Delay_us(500); //500us (???????????480?960??)
SetDQ();
Delay_us(40); //40us
//resport = GetDQ();
while(GetDQ());
Delay_us(500); //500us
SetDQ();
return resport;
}
void DS18B20WriteByte(unsigned char Dat)
{
unsigned char i;
for(i=8;i>0;i--)
{
ResetDQ(); //?15u????????,DS18B20?15-60u??
Delay_us(5); //5us
if(Dat & 0x01)
SetDQ();
else
ResetDQ();
Delay_us(65); //65us
SetDQ();
Delay_us(2); //????????1us
Dat >>= 1;
}
}
unsigned char DS18B20ReadByte(void)
{
unsigned char i,Dat;
SetDQ();
Delay_us(5);
for(i=8;i>0;i--)
{
Dat >>= 1;
ResetDQ(); //???????????????15u?,????????15u???
Delay_us(5); //5us
SetDQ();
Delay_us(5); //5us
if(GetDQ())
Dat|=0x80;
else
Dat&=0x7f;
Delay_us(65); //65us
SetDQ();
}
return Dat;
}
void ReadRom(unsigned char *Read_Addr)
{
unsigned char i;
DS18B20WriteByte(ReadROM);
for(i=8;i>0;i--)
{
*Read_Addr=DS18B20ReadByte();
Read_Addr++;
}
}
void DS18B20Init(unsigned char Precision,unsigned char AlarmTH,unsigned char AlarmTL)
{
DisableINT();
ResetDS18B20();
DS18B20WriteByte(SkipROM);
DS18B20WriteByte(WriteScratchpad);
DS18B20WriteByte(AlarmTL);
DS18B20WriteByte(AlarmTH);
DS18B20WriteByte(Precision);
ResetDS18B20();
DS18B20WriteByte(SkipROM);
DS18B20WriteByte(CopyScratchpad);
EnableINT();
while(!GetDQ()); //?????? ///
}
void DS18B20StartConvert(void)
{
DisableINT();
ResetDS18B20();
DS18B20WriteByte(SkipROM);
DS18B20WriteByte(StartConvert);
EnableINT();
}
void DS18B20_Configuration(void)
{
// GPIO_InitTypeDef GPIO_InitStructure;
//
// RCC_APB2PeriphClockCmd(DS_RCC_PORT, ENABLE);
// GPIO_InitStructure.GPIO_Pin = DS_DQIO;
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //¿ªÂ©Êä³ö
// GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //2MʱÖÓËÙ¶È
// GPIO_Init(DS_PORT, &GPIO_InitStructure);
}
void ds18b20_init(void)
{
DS18B20_Configuration();
DS18B20Init(DS_PRECISION, DS_AlarmTH, DS_AlarmTL);
DS18B20StartConvert();
}
unsigned short ds18b20_read(void)
{
unsigned char TemperatureL,TemperatureH;
unsigned int Temperature;
DisableINT();
ResetDS18B20();
DS18B20WriteByte(SkipROM);
DS18B20WriteByte(ReadScratchpad);
TemperatureL=DS18B20ReadByte();
TemperatureH=DS18B20ReadByte();
ResetDS18B20();
EnableINT();
if(TemperatureH & 0x80)
{
TemperatureH=(~TemperatureH) | 0x08;
TemperatureL=~TemperatureL+1;
if(TemperatureL==0)
TemperatureH+=1;
}
TemperatureH=(TemperatureH<<4)+((TemperatureL&0xf0)>>4);
TemperatureL=TempX_TAB[TemperatureL&0x0f];
//bit0-bit7????,bit8-bit14????,bit15????
Temperature=TemperatureH;
Temperature=(Temperature<<8) | TemperatureL;
DS18B20StartConvert();
return Temperature;
//??16??? bit0-bit7????,bit8-bit14????,bit15????
}