Crate nmea0183

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NMEA 0183 parser. Implemented most used sentences like RMC, VTG, GGA, GLL. Parser do not use heap memory and relies only on core.

You should instantiate Parser with new and than use methods like parse_from_byte or parse_from_bytes. If parser accumulates enough data it will return ParseResult on success or &str that describing an error.

You do not need to do any preprocessing such as split data to strings or NMEA sentences.

§Examples

If you could read a one byte at a time from the receiver you may use parse_from_byte:

use nmea0183::{Parser, ParseResult};

let nmea = b"$GPGGA,145659.00,5956.695396,N,03022.454999,E,2,07,0.6,9.0,M,18.0,M,,*62\r\n$GPGGA,,,,,,,,,,,,,,*00\r\n";
let mut parser = Parser::new();
for b in &nmea[..] {
    if let Some(result) = parser.parse_from_byte(*b) {
        match result {
            Ok(ParseResult::GGA(Some(gga))) => { }, // Got GGA sentence
            Ok(ParseResult::GGA(None)) => { }, // Got GGA sentence without valid data, receiver ok but has no solution
            Ok(_) => {}, // Some other sentences..
            Err(e) => { } // Got parse error
        }
    }
}

If you read many bytes from receiver at once or want to parse NMEA log from text file you could use Iterator-style:

use nmea0183::{Parser, ParseResult};

let nmea = b"$GPGGA,,,,,,,,,,,,,,*00\r\n$GPRMC,125504.049,A,5542.2389,N,03741.6063,E,0.06,25.82,200906,,,A*56\r\n";
let mut parser = Parser::new();

for result in parser.parse_from_bytes(&nmea[..]) {
    match result {
        Ok(ParseResult::RMC(Some(rmc))) => { }, // Got RMC sentence
        Ok(ParseResult::GGA(None)) => { }, // Got GGA sentence without valid data, receiver ok but has no solution
        Ok(_) => {}, // Some other sentences..
        Err(e) => { } // Got parse error
    }
}

It is possible to ignore some sentences or sources. You can set filter on Parser like so:

use nmea0183::{Parser, ParseResult, Sentence, Source};

let parser_only_gps_gallileo = Parser::new()
    .source_filter(Source::GPS | Source::Gallileo);
let parser_only_rmc_gga_gps = Parser::new()
    .source_only(Source::GPS)
    .sentence_filter(Sentence::RMC | Sentence::GGA);

§Panics

Should not panic. If so please report issue on project page.

§Errors

Unsupported sentence type. - Got currently not supported sentence.

Checksum error! - Sentence has wrong checksum, possible data corruption.

Source is not supported! - Unknown source, new sattelite system is launched? :)

NMEA format error! - Possible data corruption. Parser drops all accumulated data and starts seek new sentences.

It’s possible to got other very rare error messages that relates to protocol errors. Receivers nowadays mostly do not violate NMEA specs.

§Planned features

GSA and GSV parsing.

Modules§

coords: Structures that describes coordinates that may be parsed from NMEA sentences.
datetime: NMEA date and time structures.
satellite: Structures that describe satellites in views .

Structs§

GGA: Geographic coordinates including altitude, GPS solution quality, DGPS usage information.
GLL: Geographic latitude ang longitude sentence with time of fix and receiver state.
GSA: GPS DOP and active satellites
GSV: Satellites in views including the number of SVs in view, the PRN numbers, elevations, azimuths, and SNR values.
Parser: Parses NMEA sentences and stores intermediate parsing state. Parser is tolerant for errors so you should not reinitialize it after errors.
RMC: Recommended Minimum Sentence for any GNSS source.
SentenceMask: Mask for Sentence filter in Parser.
SourceMask: Mask for Source filter in Parser.
VTG: The actual course and speed relative to the ground.

Enums§

FixType: Receiver mode of positioning.
GPSQuality: Quality of GPS solution
Mode: Receiver mode of operation.
ParseResult: The NMEA sentence parsing result. Sentences with many null fields or sentences without valid data is also parsed and returned as None. None ParseResult may be interpreted as working receiver but without valid data.
Sentence: Various kinds of NMEA sentence like RMC, VTG or other. Used for filter by sentence type in Parser.
Source: Source of NMEA sentence like GPS, GLONASS or other.

Constants§

MAX_SENTENCE_LENGTH: Maximum allowed sentence length, according to NMEA 183 docs should be not more than 79 chars. Disable strict feature to parse up to 120 chars.

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