File syn_nmea.h¶

FileList > proto > syn_nmea.h

NMEA 0183 / GNSS sentence parser and encoder. More...

#include "../common/syn_defs.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_NMEA_GGA Parsed NMEA GGA (Fix Data) Structure.
struct	SYN_NMEA_GSA Parsed NMEA GSA (DOP & Active Satellites) Structure.
struct	SYN_NMEA_Parser Streaming NMEA Parser State Machine.
struct	SYN_NMEA_RMC Parsed NMEA RMC (Recommended Minimum Data) Structure.
struct	SYN_NMEA_VTG Parsed NMEA VTG (Velocity & Course) Structure.
struct	SYN_NMEA_ZDA Parsed NMEA ZDA (UTC Date & Time) Structure.

Public Types¶

Type	Name
enum	SYN_NMEA_FixQuality GPS Fix Quality Enum (from GGA)
enum	SYN_NMEA_SentenceType NMEA Sentence Type Enum.

Public Functions¶

Type	Name
uint8_t	syn_nmea_checksum (const char * sentence) Calculate XOR checksum of an NMEA sentence payload (between '$' and '').*
SYN_NMEA_SentenceType	syn_nmea_get_type (const char * sentence) Identify sentence type from NMEA string.
double	syn_nmea_parse_coord (const char * nmea_coord, char dir) Parse NMEA DDMM.MMMM coordinate string and direction indicator.
bool	syn_nmea_parse_gga (const char * sentence, SYN_NMEA_GGA * gga) Parse a $GPGGA / $GNGGA sentence.
bool	syn_nmea_parse_gsa (const char * sentence, SYN_NMEA_GSA * gsa) Parse a $GPGSA / $GNGSA sentence.
bool	syn_nmea_parse_rmc (const char * sentence, SYN_NMEA_RMC * rmc) Parse a $GPRMC / $GNRMC sentence.
bool	syn_nmea_parse_vtg (const char * sentence, SYN_NMEA_VTG * vtg) Parse a $GPVTG / $GNVTG sentence.
bool	syn_nmea_parse_zda (const char * sentence, SYN_NMEA_ZDA * zda) Parse a $GPZDA / $GNZDA sentence.
bool	syn_nmea_parser_feed (SYN_NMEA_Parser * parser, char byte, char * out_sentence) Feed a byte into the NMEA streaming parser.
void	syn_nmea_parser_init (SYN_NMEA_Parser * parser) Initialize an NMEA streaming parser.
bool	syn_nmea_validate (const char * sentence) Validate an NMEA sentence string (checks start '$', 'XX' checksum, and CRLF).*

Macros¶

Type	Name
define	SYN_NMEA_MAX_SENTENCE_LEN `82`

Detailed Description¶

Provides a zero-allocation, streaming byte-at-a-time NMEA 0183 parser, sentence checksum verification, and structured data decoders for standard GNSS sentences: * GGA: Global Positioning System Fix Data * RMC: Recommended Minimum Specific GNSS Data * VTG: Course Over Ground & Ground Speed * GSA: GNSS DOP & Active Satellites * ZDA: UTC Time & Date

Public Types Documentation¶

enum SYN_NMEA_FixQuality¶

GPS Fix Quality Enum (from GGA)

enum SYN_NMEA_FixQuality {
    SYN_NMEA_FIX_INVALID = 0,
    SYN_NMEA_FIX_GPS = 1,
    SYN_NMEA_FIX_DGPS = 2,
    SYN_NMEA_FIX_PPS = 3,
    SYN_NMEA_FIX_RTK = 4,
    SYN_NMEA_FIX_FLOAT_RTK = 5,
    SYN_NMEA_FIX_ESTIMATED = 6
};

enum SYN_NMEA_SentenceType¶

NMEA Sentence Type Enum.

enum SYN_NMEA_SentenceType {
    SYN_NMEA_SENTENCE_UNKNOWN = 0,
    SYN_NMEA_SENTENCE_GGA,
    SYN_NMEA_SENTENCE_RMC,
    SYN_NMEA_SENTENCE_VTG,
    SYN_NMEA_SENTENCE_GSA,
    SYN_NMEA_SENTENCE_ZDA
};

Public Functions Documentation¶

function syn_nmea_checksum¶

Calculate XOR checksum of an NMEA sentence payload (between '$' and '*').

uint8_t syn_nmea_checksum (
    const char * sentence
)

Parameters:

sentence NMEA sentence string.

Returns:

8-bit XOR checksum value.

function syn_nmea_get_type¶

Identify sentence type from NMEA string.

SYN_NMEA_SentenceType syn_nmea_get_type (
    const char * sentence
)

Parameters:

sentence NMEA sentence string.

Returns:

SYN_NMEA_SentenceType enum.

function syn_nmea_parse_coord¶

Parse NMEA DDMM.MMMM coordinate string and direction indicator.

double syn_nmea_parse_coord (
    const char * nmea_coord,
    char dir
)

Parameters:

nmea_coord Coordinate string (e.g. "4807.038").
dir Direction char ('N', 'S', 'E', 'W').

Returns:

Decimal degrees (+N/+E, -S/-W).

function syn_nmea_parse_gga¶

Parse a $GPGGA / $GNGGA sentence.

bool syn_nmea_parse_gga (
    const char * sentence,
    SYN_NMEA_GGA * gga
)

Parameters:

sentence NMEA sentence string.
gga Pointer to destination GGA struct.

Returns:

true on success.

function syn_nmea_parse_gsa¶

Parse a $GPGSA / $GNGSA sentence.

bool syn_nmea_parse_gsa (
    const char * sentence,
    SYN_NMEA_GSA * gsa
)

Parameters:

sentence NMEA sentence string.
gsa Pointer to destination GSA struct.

Returns:

true on success.

function syn_nmea_parse_rmc¶

Parse a $GPRMC / $GNRMC sentence.

bool syn_nmea_parse_rmc (
    const char * sentence,
    SYN_NMEA_RMC * rmc
)

Parameters:

sentence NMEA sentence string.
rmc Pointer to destination RMC struct.

Returns:

true on success.

function syn_nmea_parse_vtg¶

Parse a $GPVTG / $GNVTG sentence.

bool syn_nmea_parse_vtg (
    const char * sentence,
    SYN_NMEA_VTG * vtg
)

Parameters:

sentence NMEA sentence string.
vtg Pointer to destination VTG struct.

Returns:

true on success.

function syn_nmea_parse_zda¶

Parse a $GPZDA / $GNZDA sentence.

bool syn_nmea_parse_zda (
    const char * sentence,
    SYN_NMEA_ZDA * zda
)

Parameters:

sentence NMEA sentence string.
zda Pointer to destination ZDA struct.

Returns:

true on success.

function syn_nmea_parser_feed¶

Feed a byte into the NMEA streaming parser.

bool syn_nmea_parser_feed (
    SYN_NMEA_Parser * parser,
    char byte,
    char * out_sentence
)

Parameters:

parser Pointer to parser instance.
byte Received character.
out_sentence Output buffer for completed NMEA sentence string (if returns true).

Returns:

true if a complete, valid NMEA sentence was received.

function syn_nmea_parser_init¶

Initialize an NMEA streaming parser.

void syn_nmea_parser_init (
    SYN_NMEA_Parser * parser
)

Parameters:

parser Pointer to parser state machine.

function syn_nmea_validate¶

Validate an NMEA sentence string (checks start '$', '*XX' checksum, and CRLF).

bool syn_nmea_validate (
    const char * sentence
)

Parameters:

sentence NMEA sentence string.

Returns:

true if valid sentence and matching checksum.

Macro Definition Documentation¶

define SYN_NMEA_MAX_SENTENCE_LEN¶

#define SYN_NMEA_MAX_SENTENCE_LEN `82`

Max NMEA 0183 sentence length

The documentation for this class was generated from the following file src/syntropic/proto/syn_nmea.h