18b20.c

通过车载终端采集GPS数据

#include "1wire.h"
#include "18B20.h"
#include <stdio.h>
#include "16c554.h"
#include <string.h>

extern char debug_msg[1024];
void T18B20Debug(char* pVal)
{
/*    if (1 == value)
    {
        sprintf(debug_msg, "有温度传感器");
        siob_send(debug_msg, strlen(debug_msg));
    }
    else
    {
        sprintf(debug_msg, "无温度传感器");
        siob_send(debug_msg, strlen(debug_msg));
    }*/
    sprintf(debug_msg, "%02bX:%02bX,%02bX:%02bX:%02bX:%02bX,%02bX:%02bX:%02bX,\r\n ", \
                pVal[0], pVal[1], pVal[2], pVal[3], pVal[4], pVal[5], pVal[6], pVal[7], pVal[8]);
    siob_send(debug_msg, strlen(debug_msg));
}

char ggggdebug[9];
long gTemperature;//值：实际温度*10000
unsigned char g18b20Point=0;
void T18B20process()
{
    unsigned char i;
    unsigned char val1, val2;
    unsigned char crc;
    
/*    i = wire1_reset();
//    T18B20Debug(i);
    wire1_writebyte(T18B20_READROM);  //read rom
    for (i=0; i<8; i++)
        ggggdebug[i] = wire1_readbyte();
    T18B20Debug(ggggdebug);*/

    if (0 == g18b20Point)
    {
        g18b20Point = 1;
        wire1_reset();
        wire1_writebyte(T18B20_SKIPROM);
        wire1_writebyte(T18B20_CONVERTT);
    }
    else
    {
        g18b20Point = 0;
        wire1_reset();
        wire1_writebyte(T18B20_SKIPROM);
        wire1_writebyte(T18B20_READSCRATCHPAD);
        for (i=0; i<9; i++)
            ggggdebug[i] = wire1_readbyte();
 //       T18B20Debug(ggggdebug);
    }
/*    i = wire1_reset();
    if (1 == i)
    {
        //有温度传感器
        wire1_writebyte(T18B20_SKIPROM);
        wire1_writebyte(T18B20_CONVERTT);
    
        wire1_reset();
        wire1_writebyte(T18B20_SKIPROM);
        wire1_writebyte(T18B20_READSCRATCHPAD);
        val1 = wire1_readbyte();
        val2 = wire1_readbyte();
        for (i=0; i<7; i++)
            crc = wire1_readbyte();
        
        for (i=0; i<9; i++)
            debug[i] = wire1_readbyte();
        T18B20Debug(debug);
        //chech crc
        //compute temperature
        gTemperature = ((val2&0x7)*256+val1)*625;
        if (val2 > 0xf0)
            gTemperature = -gTemperature;
    }
    else
    {
        //无温度传感器
    }*/
    
}

static code const unsigned char  dscrc_table[] = {
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
};

/***********************************
*校验和是否吻合
*num：输入长度
*Src：最后一个字节为校验和，其余为内容
*返回值：1：是；0：否
***********************************/
unsigned char Ds18b20_crc(unsigned char num,unsigned char *Src)
{
    unsigned char i;
    unsigned char crcdata = 0;
    for ( i = 0; i < num-1; i++ )
    {
        crcdata = crcdata ^ (*Src); Src++;
        crcdata = dscrc_table[crcdata];
    }
    if (crcdata==*Src) 
        return 1;
    else 
        return 0;
}