基于51单片机和Labview的多路温度采集系统

原理图

外接USB转TTL线

最小系统

传感器

程序

/*************************此部分为18B20的驱动程序

*************************************/

#include

#include

sbit D18B20=P3^7;

#define NOP() _nop_() /* 定义空指令 */

#define _Nop() _nop_() /*定义空指令*/

void TempDelay (unsigned char idata us);

void Init18b20 (void);

void WriteByte (unsigned char idata wr); //单字节写入

void read_bytes (unsigned char idata j);

unsigned char CRC (unsigned char j);

void GemTemp (void);

void Config18b20 (void);

void ReadID (void);

void TemperatuerResult(void);

bit flag;

unsigned int idata Temperature;

unsigned char idata temp_buff[9]; //存储读取的字节，read scratchpad为9字节，read rom ID为8字节

unsigned char idata id_buff[8];

unsigned char idata *p,TIM;

unsigned char idata crc_data;

unsigned char code CrcTable [256]={

0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,

157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,

35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,

190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,

70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,

219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,

101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,

248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,

140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,

17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,

175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,

50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,

202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,

87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,

233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,

116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53};

//

/************************************************************

*Function:延时处理

*parameter:

*Return:

*Modify:

*************************************************************/

void TempDelay (unsigned char idata us)

{

while(us--);

}

/************************************************************

*Function:18B20初始化

*parameter:

*Return:

*Modify:

*************************************************************/

void Init18b20 (void)

{

D18B20=1;

_nop_();

D18B20=0;

TempDelay(75); //delay 530 uS//80

_nop_();

D18B20=1;

TempDelay(12); //delay 100 uS//14

_nop_();

_nop_();

_nop_();

if(D18B20==0)

flag = 1; //detect 1820 success!

else

flag = 0; //detect 1820 fail!

TempDelay(18); //20

_nop_();

_nop_();

D18B20 = 1;

}

/************************************************************

*Function:向18B20写入一个字节

*parameter:

*Return:

*Modify:

*************************************************************/

void WriteByte (unsigned char idata wr) //单字节写入

{

unsigned char idata i;

for (i=0;i<8;i++)

{

D18B20 = 0;

_nop_();

D18B20=wr&0x01;

TempDelay(2); //delay 45 uS //3

_nop_();

_nop_();

D18B20=1;

wr >>= 1;

}

}

/************************************************************

*Function:读18B20的一个字节

*parameter:

*Return:

*Modify:

*************************************************************/

unsigned char ReadByte (void) //读取单字节

{

unsigned char idata i,u=0;

for(i=0;i<8;i++)

{

D18B20 = 0;

u >>= 1;

D18B20 = 1;

if(D18B20==1)

u |= 0x80;

TempDelay (2);

_nop_();

}

return(u);

}

/************************************************************

*Function:读18B20

*parameter:

*Return:

*Modify:

*************************************************************/

void read_bytes (unsigned char idata j)

{

unsigned char idata i;

for(i=0;i{

*p = ReadByte();

p++;

}

}

/************************************************************

*Function:CRC校验

*parameter:

*Return:

*Modify:

*************************************************************/

unsigned char CRC (unsigned char j)

{

unsigned char idata i,crc_data=0;

for(i=0;icrc_data = CrcTable[crc_data^temp_buff[i]];

return (crc_data);

}

/************************************************************

*Function:读取温度

*parameter:

*Return:

*Modify:

*************************************************************/

void GemTemp (void)

{

read_bytes (9);

if (CRC(9)==0) //校验正确

{

Temperature = temp_buff[1]*0x100 + temp_buff[0];

// Temperature *= 0.625;

Temperature /= 16;

TempDelay(1);

}

}

/************************************************************

*Function:内部配置

*parameter:

*Return:

*Modify:

*************************************************************/

void Config18b20 (void) //重新配置报警限定值和分辨率

{

Init18b20();

WriteByte(0xcc); //skip rom

WriteByte(0x4e); //write scratchpad

WriteByte(0x19); //上限

WriteByte(0x1a); //下限

WriteByte(0x7f); //set 11 bit (0.125)

Init18b20();

WriteByte(0xcc); //skip rom

WriteByte(0x48); //保存设定值

Init18b20();

WriteByte(0xcc); //skip rom

WriteByte(0xb8); //回调设定值

}

/************************************************************

*Function:读18B20ID

*parameter:

*Return:

*Modify:

*************************************************************/

void ReadID (void)//读取器件 id

{

Init18b20();

WriteByte(0x33); //read rom

read_bytes(8);

}

/************************************************************

*Function:18B20ID全处理

*parameter:

*Return:

*Modify:

*************************************************************/

void TemperatuerResult(void)

{

p = id_buff;

ReadID();

Config18b20();

Init18b20 ();

WriteByte(0xcc); //skip rom

WriteByte(0x44);

Init18b20 ();

WriteByte(0xcc); WriteByte(0xbe); p = temp_buff;

GemTemp();

}

//Temperature convert

//skip rom

//read Temperature

void GetTemp()

{

if(TIM==100) //每隔 1000ms 读取温度

{ TIM=0;

TemperatuerResult();

}

}

/*************************************

[ t1 (10ms)中断] 中断

*************************************/

void timer1() interrupt 1

{

TH0=(65536-10000)/256;

TL0=(65536-10000)%256;

TIM++;

}

}

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