本帖最后由 51控 于 2015-9-4 08:16 編輯
/*************************此部分為18B20的驅(qū)動程序*************************************/ #include <reg52.H> #include <intrins.h> sbit D18B20=P3^7; #define NOP() _nop_() /* 定義空指令 */ #define _Nop() _nop_() /*定義空指令*/ void TempDelay (unsigned char idata us); void Init18b20 (void); void WriteByte (unsigned char idata wr); //單字節(jié)寫入 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]; //存儲讀取的字節(jié),read scratchpad為9字節(jié),read rom ID為8字節(jié) 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:延時(shí)處理 *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(80); //delay 530 uS//80
_nop_();
D18B20=1;
TempDelay(14); //delay 100 uS//14
_nop_();
_nop_();
_nop_();
if(D18B20==0)
flag = 1; //detect 1820 success!
else
flag = 0; //detect 1820 fail!
TempDelay(20); //20
_nop_();
_nop_();
D18B20 = 1; } /************************************************************ *Function:向18B20寫入一個(gè)字節(jié) *parameter: *Return: *Modify: *************************************************************/
void WriteByte (unsigned char idata wr) //單字節(jié)寫入
{
unsigned char idata i;
for (i=0;i<8;i++)
{
D18B20 = 0;
_nop_();
D18B20=wr&0x01;
TempDelay(3); //delay 45 uS //5
_nop_();
_nop_();
D18B20=1;
wr >>= 1;
}
} /************************************************************ *Function:讀18B20的一個(gè)字節(jié) *parameter: *Return: *Modify: *************************************************************/
unsigned char ReadByte (void) //讀取單字節(jié)
{
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:讀18B20 *parameter: *Return: *Modify: *************************************************************/
void read_bytes (unsigned char idata j) {
unsigned char idata i;
for(i=0;i<j;i++)
{
*p = ReadByte();
p++;
}
} /************************************************************ *Function:CRC校驗(yàn) *parameter: *Return: *Modify: *************************************************************/
unsigned char CRC (unsigned char j)
{
unsigned char idata i,crc_data=0;
for(i=0;i<j;i++) //查表校驗(yàn)
crc_data = CrcTable[crc_data^temp_buff];
return (crc_data);
} /************************************************************ *Function:讀取溫度 *parameter: *Return: *Modify: *************************************************************/
void GemTemp (void) { read_bytes (9);
if (CRC(9)==0) //校驗(yàn)正確
{
Temperature = temp_buff[1]*0x100 + temp_buff[0]; //
Temperature *= 0.625;
Temperature /= 16;
TempDelay(1);
}
} /************************************************************ *Function:內(nèi)部配置 *parameter: *Return: *Modify: *************************************************************/
void Config18b20 (void) //重新配置報(bào)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 12 bit (0.125)
Init18b20();
WriteByte(0xcc); //skip rom
WriteByte(0x48); //保存設(shè)定值
Init18b20(); WriteByte(0xcc); //skip rom
WriteByte(0xb8); //回調(diào)設(shè)定值 } /************************************************************ *Function:讀18B20ID *parameter: *Return: *Modify: *************************************************************/
void ReadID (void)//讀取器件 id
{
Init18b20();
WriteByte(0x33); //read rom
read_bytes(8);
} /************************************************************ *Function:18B20ID全處理 *parameter: *Return: *Modify: *************************************************************/
void TemperatuerResult(void)
{
p = id_buff;
ReadID();
Config18b20();
Init18b20 ();
WriteByte(0xcc); //skip rom
WriteByte(0x44); //Temperature convert
Init18b20 ();
WriteByte(0xcc); //skip rom
WriteByte(0xbe); //read Temperature
p = temp_buff;
GemTemp();
}
void GetTemp()
{
if(TIM==100) //每隔 1000ms 讀取溫度
{
TIM=0;
TemperatuerResult();
}
} /************************************* [ t1 (10ms)中斷] 中斷 *************************************/
void T1zd(void) interrupt 3
{
TH1 = 0xD8; //10
TL1 = 0xF0;
TIM++;
}
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