utils.c

 /*  the radian_trx SW shall not be distributed  nor used for commercial product*/
 /*  it is exposed just to demonstrate CC1101 capability to reader water meter indexes */
 /*  there is no Warranty on radian_trx SW */
 
void show_in_hex(uint8_t* buffer, size_t len)
{
  int i=0;
	for (i=0 ; i<len ; i++) {
		if (!(i % 16))
			puts("");

		printf("%02X ", buffer[i]);
	}
	printf("\n");
}

void show_in_hex_array(uint8_t* buffer, size_t len)
{
  int i=0;
	for (i=0 ; i<len ; i++) {
		if (!(i % 16))printf("\r\n");
		printf("0x%02X,", buffer[i]);
	}
	printf("\n");
}

void show_in_hex_one_line(uint8_t* buffer, size_t len)
{
  int i=0;
	for (i=0 ; i<len ; i++) {
		printf("%02X ", buffer[i]);
	}
}

void show_in_hex_one_line_GET(uint8_t* buffer, size_t len)
{
  int i=0;
	for (i=0 ; i<len ; i++) {
		printf("%02XS", buffer[i]);
	}
}

void show_in_bin(uint8_t* buffer, size_t len)
{
	const uint8_t *ptr;
	uint8_t mask;
	for ( ptr = buffer; len--; ptr++ )
	{		
		for ( mask = 0x80 ; mask ; mask >>= 1 )
		{
			(mask & *ptr) > 0 ?  printf("1") : printf("0");
		}
		printf(" ");
	}
	printf("\n");
}

void echo_debug(T_BOOL l_flag,char *fmt, ...)
{
 if (l_flag)
 {
    va_list args;
    va_start (args, fmt);
    vprintf (fmt, args);
    fflush(stdout);
 }

}

void print_time(void)
{/*
	time_t mytime;
    mytime = time(NULL);
    printf(ctime(&mytime));*/
	
	
  time_t rawtime;
  struct tm * timeinfo;
  char buffer [80];

  time (&rawtime);
  timeinfo = localtime (&rawtime);

  strftime (buffer,80,"%d/%m/%Y %X",timeinfo);
  printf("%s",buffer);

}



/*----------------------------------------------------------------------------*/
#define		CRC_START_KERMIT	0x0000
#define		CRC_POLY_KERMIT		0x8408
static uint8_t		crc_tab_init		= 0;
static uint16_t		crc_tab[256];
/*----------------------------------------------------------------------------*/
/* https://www.libcrc.org/
 * static void init_crc_tab( void );
 *
 * For optimal performance, the  CRC Kermit routine uses a lookup table with
 * values that can be used directly in the XOR arithmetic in the algorithm.
 * This lookup table is calculated by the init_crc_tab() routine, the first
 * time the CRC function is called.
 */

static void init_crc_tab( void ) {

	uint16_t i;
	uint16_t j;
	uint16_t crc;
	uint16_t c;

	for (i=0; i<256; i++) {

		crc = 0;
		c   = i;

		for (j=0; j<8; j++) {

			if ( (crc ^ c) & 0x0001 ) crc = ( crc >> 1 ) ^ CRC_POLY_KERMIT;
			else                      crc =   crc >> 1;

			c = c >> 1;
		}

		crc_tab[i] = crc;
	}

	crc_tab_init = 1;

}  /* init_crc_tab */


/* https://www.libcrc.org/
 * uint16_t crc_kermit( const unsigned char *input_str, size_t num_bytes );
 *
 * The function crc_kermit() calculates the 16 bits Kermit CRC in one pass for
 * a byte string of which the beginning has been passed to the function. The
 * number of bytes to check is also a parameter.
 */

uint16_t crc_kermit( const unsigned char *input_ptr, size_t num_bytes ) {

	uint16_t crc;
	uint16_t tmp;
	uint16_t short_c;
	uint16_t low_byte;
	uint16_t high_byte;
	const unsigned char *ptr;
	size_t a;

	if ( ! crc_tab_init ) init_crc_tab();

	crc = CRC_START_KERMIT;
	ptr = input_ptr;

	for (a=0; a<num_bytes; a++) {

		short_c = 0x00ff & (uint16_t) *ptr;
		tmp     =  crc       ^ short_c;
		crc     = (crc >> 8) ^ crc_tab[ tmp & 0xff ];

		ptr++;
	}

	low_byte  = (crc & 0xff00) >> 8;
	high_byte = (crc & 0x00ff) << 8;
	crc       = low_byte | high_byte;

	return crc;

}  /* crc_kermit */

/*----------------------------------------------------------------------------*/
/**
 * Reverses the bit order of the input data and adds a start bit before and a stop bit
 * after each byte.
 *
 * @param inputBuffer Points to the unencoded data.
 * @param inputBufferLen Number of bytes of unencoded data.
 * @param outputBuffer Points to the encoded data.
 * @param outputBufferLen Number of bytes of encoded data.
 */
int encode2serial_1_3(uint8_t *inputBuffer, int inputBufferLen, uint8_t *outputBuffer) {

	// Adds a start and stop bit and reverses the bit order.
	// 76543210 76543210 76543210 76543210
	// is encoded to:
	// #0123456 7###0123 4567###0 1234567# ##012345 6s7# (# -> Start/Stop bit)

	int bytepos;
	int bitpos;
	int i;
	int j = 0;
	
   for (i=0 ; i < (inputBufferLen * 8) ; i++) {
//printf("\r\ni=%u",i);
		if (i % 8 == 0) {
		   if (i > 0) {
//printf(" j=%u stopBIT",j);
			  // Insert stop bit (3)
			  bytepos = j / 8;
			  bitpos = j % 8;
			  outputBuffer[bytepos] |= 1 << (7 - bitpos);
			  j++;
			
			  bytepos = j / 8;
			  bitpos = j % 8;
			  outputBuffer[bytepos] |= 1 << (7 - bitpos);
			  j++;
			
			  bytepos = j / 8;
			  bitpos = j % 8;
			  outputBuffer[bytepos] |= 1 << (7 - bitpos);
			  j++;
		    } //stop bit
		
			// Insert start bit (0)
			bytepos = j / 8;
			bitpos = j % 8;
//printf(" j=%u startBIT",j);
			outputBuffer[bytepos] &= ~(1 << (7 - bitpos));
			j++;
		}// start stop bit

		bytepos = i / 8;
		bitpos = i % 8;
		uint8_t mask = 1 << bitpos;
		if ((inputBuffer[bytepos] & mask) > 0) {
			bytepos = j / 8;
			bitpos = 7 - (j % 8);
			outputBuffer[bytepos] |= 1 << bitpos;

		} else {
			bytepos = j / 8;
			bitpos = 7 - (j % 8);
			outputBuffer[bytepos] &= ~(1 << bitpos);
		}

		j++;
	}//for
	
	//insert additional stop bit until end of byte
    while (j%8 > 0)
	{
	   	bytepos = j / 8;
		bitpos = 7 - (j % 8);
		outputBuffer[bytepos] |= 1 << bitpos;
		j++;
	}
	outputBuffer[bytepos+1] = 0xFF;
	return bytepos+2;
}

int Make_Radian_Master_req(uint8_t *outputBuffer,uint8_t year,uint32_t serial)
{ 
  uint16_t crc;
  uint8_t to_encode[] ={0x13,0x10,0x00,0x45,0xFF,0xFF,0xFF,0xFF,0x00,0x45,0x20,0x0A,0x50,0x14,0x00,0x0A,0x40,0xFF,0xFF}; //les 2 derniers octet sont en reserve pour le CKS ainsi que le serial number
  uint8_t synch_pattern[] ={0x50,0x00,0x00,0x00,0x03,0xFF,0xFF,0xFF,0xFF};
  uint8_t TS_len_u8;
  
  to_encode[4] = year;
  to_encode[5] = (uint8_t)((serial&0x00FF0000)>>16);
  to_encode[6] = (uint8_t)((serial&0x0000FF00)>>8);
  to_encode[7] = (uint8_t) (serial&0x000000FF);
  crc = crc_kermit(to_encode,sizeof(to_encode)-2);
  //printf("crc:%x\r\n",crc);
  to_encode[sizeof(to_encode)-2]=(uint8_t)((crc&0xFF00)>>8);
  to_encode[sizeof(to_encode)-1]=(uint8_t)(crc&0x00FF);
  //show_in_hex_one_line(to_encode,sizeof(to_encode));
  memcpy(outputBuffer,synch_pattern,sizeof(synch_pattern));
  TS_len_u8=encode2serial_1_3(to_encode,sizeof(to_encode),&outputBuffer[sizeof(synch_pattern)]);
  return TS_len_u8+sizeof(synch_pattern);
}