This library parses and encodes some NMEA 0183 sentences. These are typically used by GPS recievers to send information on position, heading, speed and acuracy. The official standard can be found here and is described in clear terms here.

Typically, you will get NMEA sentences via the serial port from a GPS module. You can use the serialport NPM package to read the lines (and the @serialport/parser-readline parser to separate the input by "\r\n"). Each line can then be passed into parseNmeaSentence to get the decoded packet.

const SerialPort = require("serialport");
const Readline = require("@serialport/parser-readline")
const nmea = require("nmea-simple");

const port = new SerialPort(
    "/dev/ttyUSB0",
    {
        baudRate: 9600
    }
);

const parser = port.pipe(new Readline({ delimiter: '\r\n' }))

parser.on("data", line => {
    try {
        const packet = nmea.parseNmeaSentence(line);

        if (packet.sentenceId === "RMC" && packet.status === "valid") {
            console.log("Got location via RMC packet:", packet.latitude, packet.longitude);
        }

        if (packet.sentenceId === "GGA" && packet.fixType !== "none") {
            console.log("Got location via GGA packet:", packet.latitude, packet.longitude);
        }

        if (packet.sentenceId === "GSA") {
            console.log("There are " + packet.satellites.length + " satellites in view.");
        }
    } catch (error) {
        console.error("Got bad packet:", line, error);
    }
});

This project is written in TypeScript. The library can be used by plain JavaScript as shown above, and the typing information is also included with the library so that anyone wishing to use TypeScript will gain the benefits of the type information.

The following sentence types can be parsed by this library:

• APB
• BWC
• DBT
• DTM
• GGA
• GLL
• GNS
• GSA
• GST
• GSV
• HDG
• HDM
• HDT
• MTK
• MWV
• RDID
• RMC
• VHW
• VTG
• ZDA

The following sentence types can be encoded by this library:

• DBT
• GGA
• GLL
• GNS
• HDM
• HDT
• MTK
• MWV
• VTG

This is a fork of the nmea package with all dependencies removed and TypeScript typing information added.

This module was based on the NPM nmea and nmea-0183 packages (with date decoding borrowed from GPS) and the documentation was expanded based on the excellent analysis and descriptions by Eric S. Raymond.