easydemo_6244s/app/crc8.c

#include "crc8.h"

/**
 * @funtion:crc8多项式冗余校验
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:initialValue,crc结果初值
 * @param 4:polynomial,多项式
 * 
 * @return :校验结果
*/
unsigned char crc8( unsigned char *pData, 
                    unsigned int dataLen,
                    unsigned char initialValue, 
                    unsigned char polynomial )
{
    unsigned char i;
    unsigned char crc;

    crc = initialValue;
    while (dataLen --)
    {
        crc ^= *pData ++;
        for( i = 0; i < 8; i++ )
        {
            if(crc & 0x80)
            {
                crc <<= 1; // shift left once
                crc ^= polynomial; // XOR with polynomial
            }
            else
            { 
                crc <<= 1; // shift left once
            }
        }
    }

    return crc;
}
/**
 * @funtion :针对温湿度传感器sht3X系列的crc8校验
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:targetCRC,对比结果CRC
 * 
 * @return :对比校验结果，=1校验成功，=0校验失败
*/
unsigned char crc8_ger( unsigned char *pData, 
                 unsigned int dataLen)
{
    return crc8(pData, dataLen, 0xff, 0x31);
}
/**
 * @funtion :针对温湿度传感器sht3X系列的crc8校验
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:targetCRC,对比结果CRC
 * 
 * @return :对比校验结果，=1校验成功，=0校验失败
*/
int crc8_gernCheckT( unsigned char *pData, 
                 unsigned int dataLen,
                 unsigned char targetCRC)
{
    if (crc8(pData, dataLen, 0xff, 0x31) == targetCRC)
    {
        return 1;
    }
    return 0;
}
/**
 * @funtion :针对温湿度传感器sht3X系列的crc8校验
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:targetCRC,对比结果CRC
 * 
 * @return :对比校验结果，=1校验成功，=0校验失败
*/
int crc8_sht3x( unsigned char *pData, 
                 unsigned int dataLen,
                 unsigned char targetCRC)
{
    if (crc8(pData, dataLen, 0xff, 0x31) == targetCRC)
    {
        return 1;
    }
    return 0;
}
/**
 * @funtion :针对温湿度传感器sht2X系列的crc8校验
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:targetCRC,对比结果CRC
 * 
 * @return :对比校验结果，=1校验成功，=0校验失败
*/
int crc8_sht2x( unsigned char *pData, 
                 unsigned int dataLen,
                 unsigned char targetCRC)
{
    if (crc8(pData, dataLen, 0x00, 0x31) == targetCRC)
    {
        return 1;
    }
    return 0;
}
/**
 * @funtion :\
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * @param 3:targetCRC,对比结果CRC
 * 
 * @return :对比校验结果，=1校验成功，=0校验失败
*/
int cmp_crc8( uint8_t *pData, 
                 uint16_t dataLen,
                 uint8_t targetCRC)
{
    if (crc8(pData, dataLen, 0x55, 0x07) == targetCRC)
    {
        return 1;
    }
    return 0;
}
/**
 * @funtion :\
 * @param 1:pData,计算数据源地址
 * @param 2:dataLen,计算数据源长度
 * 
 * @return :返回CRC结果
*/
int get_crc8( uint8_t *pData, 
                 uint16_t dataLen)
{
    return crc8(pData, dataLen, 0x55, 0x07);
}
bool checkFramLegal(uint8_t *srcBuffer, uint8_t srcLen)
{
    bool ret = false;
    uint8_t len;
    uint8_t cmd;
    uint8_t crc1;
    // uint8_t crc2;
    len = srcBuffer[0];
    cmd = srcBuffer[1];
    crc1 = srcBuffer[len];
    // crc2 = srcBuffer[len];

    if (len == (srcLen - 1))
    {
        if ((cmd & 0x80) == 0)
        {
            if (cmp_crc8(srcBuffer, srcLen - 1, crc1))
            {
                ret = true;
                // ret = cmp_crc8(srcBuffer, srcLen - 1, crc2);
            }
        }
        else
        {
            ret = true;
        }
    }

    return ret;
}

void completFramParams(uint8_t *srcBuffer, uint8_t srcLen)
{
    uint8_t *head;
    uint8_t *len;
    uint8_t *crc1;
    // uint8_t *crc2;
    uint8_t *end;
    len = &srcBuffer[0];
    crc1 = &srcBuffer[srcLen - 1];
    // crc2 = &srcBuffer[srcLen - 1];

    *len = srcLen - 1;
    *crc1 = get_crc8(srcBuffer, srcLen - 1);
    // *crc2 = get_crc8(srcBuffer, srcLen - 1);
}