数字十六进制数转字符数

/*

  帮助转换十六进制数据到格式字符串

*/

#define MAX_HEX_STR         4
#define MAX_HEX_STR_LENGTH  128
char hexStr[MAX_HEX_STR][MAX_HEX_STR_LENGTH];

uint8_t hexStrIdx = 0;

/**
  *****************************************************************************
  * @brief  helper to convert hex data into formated string
  *
    * @param[in]    data : pointer to buffer to be dumped.
    * @param[in]    dataLen : buffer length
  *
  * @return pointer to converted data
  *****************************************************************************
  */
char* hex2Str(unsigned char * data, size_t dataLen)
{
    unsigned char * pin = data;
    const char * hex = "0123456789ABCDEF";
    char * pout = hexStr[hexStrIdx];
    uint8_t i = 0;
    uint8_t idx = hexStrIdx;
    if(dataLen == 0)
    {
      pout[0] = 0;     
    } 
    else     
    {
      for(; i < dataLen - 1; ++i)
      {
          *pout++ = hex[(*pin>>4)&0xF];
          *pout++ = hex[(*pin++)&0xF];
      }
      *pout++ = hex[(*pin>>4)&0xF];
      *pout++ = hex[(*pin)&0xF];
      *pout = 0;
    }    
    
    hexStrIdx++;
    hexStrIdx %= MAX_HEX_STR;
    
    return hexStr[idx];
}