bmsvieira/nmea.js

Javascript NMEA Parser

◼️ NMEA 0183:

NMEA 0183 is a combined electrical and data specification for communication between marine electronics such as echo sounder, sonars, anemometer, gyrocompass, autopilot, GPS receivers and many other types of instruments

A sample file produced by a Tripmate 850 GPS logger. This file was produced in Leixlip, County Kildare, Ireland. The record lasts two seconds.

$GPGGA,092750.000,5321.6802,N,00630.3372,W,1,8,1.03,61.7,M,55.2,M,,*76
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,19,13,28,070,17,26,23,252,,04,14,186,14*79
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092750.000,A,5321.6802,N,00630.3372,W,0.02,31.66,280511,,,A*43
$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,16,13,28,070,17,26,23,252,,04,14,186,15*77
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092751.000,A,5321.6802,N,00630.3371,W,0.06,31.66,280511,,,A*45

For more detailed info: https://en.wikipedia.org/wiki/NMEA_0183 and https://w3.cs.jmu.edu/bernstdh/web/common/help/nmea-sentences.php

◼️ Currently Supported Formats:

• GPGGA
• GPRMC

◼️ Demo:

https://bmsvieira.github.io/nmea.js

◼️ Installation (Browser):

1 - Include JavaScript Source.

<script src="path/to/nmea.js"></script>

2 - Initilize.

document.addEventListener("DOMContentLoaded", function() {
   const demo = new Nmea();
});

◼️ Extract Information:

There are specific fields you can use for each type of NMEA Sentence, because they provide different types of information, below is a list of available fields for the currently supported NMEA sentences.

GPGGA

Field	Response Type
altitude	float
altitudeUnits	string
checksum	int
coordinates	Object: latitude, latitudeDirection, longitude, longitudeDirection
fixType	int
hdop	float
satellites	int
sentenceType	string
time	Object: hours, minutes, seconds

GPRMC

Field	Response Type
checksum	float
coordinates	Object: latitude, latitudeDirection, longitude, longitudeDirection
date	string
time	Object: hours, minutes, seconds
heading	int
magneticVariation	float
magneticVariationDirection	string
positionStatus	string
sentenceType	string
speed	float

◼️ Usage:

There are two ways of extract information, either send the NMEA sentence in the constructor or pass it as paremeter, for example:

Constructor:

demo = new Nmea("$GPRMC,001225,A,2832.1834,N,08101.0536,W,12,25,251211,1.2,E,A*03");

// Now you can explore this NMEA sentence without having to pass it as a paremeter when using the method, for example:

demo.getInfo("speed"); // 12
demo.getInfo("heading"); // 25
demo.getInfo("magneticVariation"); // 1.2
...

// You can also use Getters and Setters, for example:

API > Get

demo.altitude
demo.altitudeUnits
demo.checksum
demo.coordinates
demo.fixType
demo.hdop
demo.satellites
demo.sentenceType
demo.time
demo.date
demo.heading
demo.magneticVariation
demo.magneticVariationDirection
demo.positionStatus
demo.speed 

API > Set

// Define a new sentence in the constructor
demo.set = "$GPRMC,001225,A,2832.1834,N,08101.0536,W,12,25,251211,1.2,E,A*03";

As a paremeter:

demo = new Nmea();

// Now you have nmea.js library ready to extract information from multiple and different nmea sentences, as long as you pass it as parameter, for example:

demo.getInfo("speed", "$GPRMC,001225,A,2832.1834,N,08101.0536,W,12,25,251211,1.2,E,A*03"); // 12
demo.getInfo("heading", "$GPRMC,001225,A,2832.1834,N,08101.0536,W,12,25,251211,1.2,E,A*03"); // 25
demo.getInfo("magneticVariation", "$GPRMC,001225,A,2832.1834,N,08101.0536,W,12,25,251211,1.2,E,A*03"); // 1.2
demo.getInfo("altitudeUnits", "$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75"); // M
demo.getInfo("hdop", "$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75"); // 1.03
...