温度传感器18B20驱动程序(C语言).doc

温度传感器18B20驱动程序(C语言)

温度传感器18B20驱动程序(C语言)

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

*18B20驱动程序，DQ数据口，接P2.1

*11.0592M晶振，上拉4.7k电阻

*Author:fyb

*2005-3-25 11:23，OK!

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

＃i nclude

＃i nclude

#define uchar unsigned char

#define uint unsigned int

sbit dq = P1^7;

bit flag;

uint Temperature;

uchar temp_buff[9]; //存储读取的字节，read scratchpad为9字节，read rom

ID为8字节

uchar id_buff[8];

uchar *p;

uchar crc_data;

uchar 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, 2