溫度傳感器DS18B20驅動程序

1、精選文檔#include "ds18b20.h"#include <intrins.h>#if 0/*FUNCTION NAME: InitDS18b20 *CREATE DATE: 2009/11/12 *CREATED BY: XS *FUNCTION: 復位DS18B20和檢測存在脈沖 *MODIFY DATE: 2009/11/12 *INPUT: 無 *RETURN: 初始化成功，返回1，否則返回0 */ BOOL InitDs18b20(void) BOOL flag = FALSE;BIT bt;bt = ET0;ET0 = 0;DQ = 1; D

2、elay70us(1); /稍作延時DQ = 0; / 復位 Delay70us(8); /精確延時大于480usDQ = 1; /拉高總線,等待存在脈沖Delay70us(1);/ 60-75us之間if(0=DQ)flag = TRUE; Delay70us(8);/ 復位后大于480us延時ET0 = bt;return flag;/*FUNCTION NAME: ReadByte *CREATE DATE: 2009/11/12 *CREATED BY: XS *FUNCTION: 從DS18B20中讀取一個字節(jié)的數(shù)據(jù) *MODIFY DATE: 2009/11/12 *INPUT:

3、無 *RETURN: 讀取的數(shù)據(jù) */ UCHAR ReadByte(void)UCHAR i;UCHAR dat = 0;BIT bt;bt = ET0;ET0 = 0;for (i=0;i<8;i+)dat >>= 1;DQ = 0; Delay5us(); DQ = 1; Delay5us();if(1=DQ)dat |=0x80;Delay70us(1);ET0 = bt; return(dat);/*FUNCTION NAME: WriteByte *CREATE DATE: 2009/11/12 *CREATED BY: XS *FUNCTION: 向DS18B2

4、0中寫入一個字節(jié)的數(shù)據(jù) *MODIFY DATE: 2009/11/12 *INPUT: 寫入的數(shù)據(jù) *RETURN: 無 */ void WriteByte(UCHAR wDat)UCHAR i;BIT bt;bt = ET0;ET0 = 0; for (i=0; i<8; i+) DQ = 0;Delay5us(); if(wDat & 0x01)!=0)DQ = 1;elseDQ = 0; Delay70us(1); DQ = 1;Delay5us(); wDat >>= 1; ET0 = bt;/*FUNCTION NAME: ReadDs18b20 *CRE

5、ATE DATE: 2009/11/12 *CREATED BY: XS *FUNCTION: 從DS18B20儲存器中讀取多字節(jié)數(shù)據(jù) *MODIFY DATE: 2009/11/12 *INPUT: 讀取數(shù)據(jù)存入的地址和需要讀取數(shù)據(jù)的數(shù)量 *RETURN: 無 */ void ReadScrat(UCHAR *prDat,UCHAR num)UCHAR i;for(i=0;i<num;i+)*prDat = ReadByte();prDat+;/*FUNCTION NAME: ReadTemp *CREATE DATE: 2009/11/12 *CREATED BY: XS *FUNC

6、TION: 讀取溫度 *MODIFY DATE: 2009/11/12 *INPUT: 讀取的溫度存入的地址 *RETURN: 成功返回1，否則返回0 */ BOOL ReadTemp(float *prTemperature)UCHAR counter = 0;UCHAR tempBuff9;float tempDat = 0;ClrWDT();while(1)if(InitDs18b20()counter = 0;break;elsecounter+;if(counter>=ERR_COUNTER)/ 連續(xù)3次初始化失敗，即認為DS18B20出現(xiàn)故障return 0;WriteByt

7、e(SKIP_ROM); / 跳過讀序號列號的操作WriteByte(CONVERT_T); / 啟動溫度轉換Delay70us(20); / 延時至少500us，以供溫度轉換while(1)if(InitDs18b20()counter = 0;break;elsecounter+;if(counter>=ERR_COUNTER)/ 連續(xù)3次初始化失敗，即認為DS18B20出現(xiàn)故障return 0;WriteByte(SKIP_ROM); /跳過讀序號列號的操作WriteByte(READ_SCRAT); /讀取溫度寄存器等（共可讀9個寄存器）ReadScrat(tempBuff, 9

8、);if(0=CRC8(tempBuff,9)if(0=(tempBuff1&0x80)/為正溫度tempDat = (tempBuff1&0x07)*0x100 + tempBuff0;elsetempDat = (0xFF-tempBuff1)&0x07)*0x100 + (0x100-tempBuff0);tempDat = -tempDat;*prTemperature = tempDat * 0.0625;return TRUE;return FALSE;/*FUNCTION NAME: GetDS18B20Temperature *CREATE DATE:

9、2009/8/17 *CREATED BY: XS *FUNCTION: 采樣3次求均值作為溫度值 *MODIFY DATE: 2009/8/17 *INPUT: 溫度儲存的地址 *RETURN: 正常為1，故障為0 */ BOOL GetDS18B20Temperature(float *pgTemperature)UCHAR i;UCHAR counter = 0;float tempDat = 0;float tempVal = 0;for(i=0;i<3;)if(ReadTemp(&tempDat)tempVal += tempDat;counter = 0;i+;els

10、ecounter+;if(counter>=ERR_COUNTER)/連續(xù)10次溫度采樣錯誤，則判斷為故障，并返回return FALSE;*pgTemperature = tempVal / 3;/SendStr("boxTemp:");/print(*pgTemperature ,1);/SendChar('n');return TRUE;/*FUNCTION NAME: CRC8 *CREATE DATE: 2009/8/17 *CREATED BY: XS *FUNCTION: CRC效驗 *MODIFY DATE: 2009/8/17 *IN

11、PUT: 需要效驗的數(shù)據(jù)地址和個數(shù) *RETURN: 效驗結果 */ UCHAR CRC8(UCHAR *point,UCHAR CRClen) /效驗成功則crc返回0 UCHAR i,j,crc_8,crcbuff; crc_8 = 0; for(i=0; i<CRClen; i+) crcbuff=*point+; for(j=0;j<8; j+) if(crc_8 crcbuff)&0x01)=0) crc_8 >>= 1; else crc_8 = 0x18; crc_8 >>= 1; crc_8 |= 0x80; crcbuff >>= 1; return crc_8; /*FUNCTION NAME: Delay5us *CREATE DATE: 2009/8/17 *CREATED BY: XS *FUNCTION: 延時5us *MODIFY DATE: 2009/8/17 *INPUT: 無 *RETURN: 無 */ void Delay5us(void)/UCHAR i; /for(i=0;i<7;i+);_nop_();_nop_();#endif/*FUNCTION NAME: Delay70us *CREATE DATE: 2009/8/17 *CREATED BY: XS