十六进制转字符串接口

static uint8_t hex_to_str(char *src, char *dst)
{
    char str[8];
    int index = 0;	

	if(NULL == src || NULL == dst)
		return ERROR;
	
    for(index = 0; index < 4; index++)
    {
        str[2*index] = src[index]>>4;
        str[2*index+1] = src[index]&0xf;
    }

    for(index = 0; index < 8; index++)
    {
	    if (str[index] < 10){
	        dst[index] = str[index] + '0';
	    }else{
	        dst[index] = str[index] -10 +'A';
	    }
    }
	
	return OK;
}