NMEA

Introduction

NMEA.jl is a package for parsing NMEA GPS protocol sentences

N.B. I've just "adopted" this package from the original author. If you have any thoughts about improving the design, or if you'd like to contribute, please let me know.

Simple Example

example = NMEA.parse(raw"$GPGGA,134740.000,5540.3248,N,01231.2992,E,1,09,0.9,20.2,M,41.5,M,,0000*61")
println(example.latitude)

Old Synopsis

Types

NMEAData

stores data for last parsed sentence of all NMEA message types

GGA

Global Positioning System Fix Data

GSA

GNSS DOP and Active Satellites

ZDA

Time and Date

GBS

RAIM GNSS Satellite Fault Detection

GLL

Geographic Position - Latitude/Longitude

GSV

GNSS Satellites in View

RMC

Recommended Minimum Specific GNSS Data

VTG

Course over Ground and Ground Speed

DTM

Datum

PASHR (proprietary)

Inertial attitude data - source

Methods

parse_msg!

parses NMEA line/sentence and stores data in NMEAData; returns message type

Example

The following example reads and parses a file of NMEA data line by line and displays GGA and GSV data

NMEA

function display_GGA(m::GGA)
    println("==================================================")
    println("=============== ESSENTIAL FIX DATA ===============")
    println("System: $(get(m.system))")
    println("Time Of Day (UTC): $(get(m.time)) secs")
    println("Latitude: $(get(m.latitude))")
    println("Longitude: $(get(m.longitude))")
    println("Fix Quality: $(get(m.fix_quality))")
    println("Tracked Satellites: $(get(m.num_sats))")
    println("HDOP: $(get(m.HDOP))")
    println("Altitude (MSL): $(get(m.altitude)) m")
    println("Geoidal Seperation: $(get(m.geoidal_seperation)) m")
    println("==================================================\n")
end # function display_GGA

# initialize/construct
nmea = NMEAData()

# read file line by line
fh = open("testdata.txt", "r")
for line = readlines(fh)
    # parse each line (sentence) in NMEA file and return message type
    mtype = parse_msg!(nmea, line)

    # display GGA and GSV data
    if (mtype == "GGA")
        display_GGA(nmea.last_GGA)
    else
        continue
    end
end

Output

==================================================
=============== ESSENTIAL FIX DATA ===============
System: GPS
Time Of Day (UTC): 50632.0 secs
Latitude: 55.675155555555556
Longitude: 12.519430555555557
Fix Quality: GPS (SPS)
Tracked Satellites: 9
HDOP: 0.9
Altitude (MSL): 5.6 m
Geoidal Seperation: 41.5 m
==================================================
...