Rev Author Line No. Line
2751 kaklik 1 #include "1wire.c"
2  
2834 kaklik 3 // compute CRC
4 // *sn - pointer to the byte array
5 // num - length of array
2913 kaklik 6  
7 int8 TM_check_CRC(unsigned int8 *sn, unsigned int8 num)
2834 kaklik 8 {
9 // CRC table
10 const int8 TouchCRC[256]= {
11 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
12 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
13 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
14 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
15 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
16 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
17 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
18 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
19 140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,
20 17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,
21 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,
22 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
23 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
24 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
25 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
26 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53};
27  
28 int8 CRC;
29 int8 i;
30  
31 CRC=0;
32 for(i=0;i<num;i++) CRC=TouchCRC[CRC ^ *(sn+i)];
33 return(CRC);
34 }
35  
36  
2751 kaklik 37 float ds1820_read()
38 {
2836 kaklik 39 unsigned int1 ready=0;
2834 kaklik 40 int8 SN[10];
41 unsigned int8 n;
2751 kaklik 42 float result;
43  
44 onewire_reset();
45 onewire_write(0xCC);
46 onewire_write(0x44);
47  
2836 kaklik 48 for(n=0;n<200;n++) // wait until sensor is busy or timeout will be over
49 {
50 ready = onewire_read();
51 if(ready == TRUE) break;
52 delay_ms(1);
53 }
2751 kaklik 54  
55 onewire_reset();
56 onewire_write(0xCC);
57 onewire_write(0xBE);
58  
2834 kaklik 59 for(n=0;n<9;n++) SN[n]=onewire_read();
2913 kaklik 60 // if ((SN[8]==TM_check_CRC(SN,8))&&(SN[7]==0x10)) // Check CRC and family code to prevent O's error
61 if ((SN[7]==0x10)) // Check CRC and family code to prevent O's error
2834 kaklik 62 {
63 result=make16(SN[1],SN[0]);
64 result=result*6+result/4; // 1bit = 0,0625gradC recalculate to 1/100gradC
65 }
66 else
67 {
2836 kaklik 68 result=-27315;
2834 kaklik 69 }
2751 kaklik 70 return(result);
71 }