National Marine Electronics Association (NMEA)
NMEA Stands For 'National Marine Electronics Association', an organization started to help produce a wiring and data standard between different manufactures' products in the U.S. marine electronics industry. Today NMEA includes the world markets; bringing together all aspects of the global industry for the betterment of selling product to consumers.
NMEA 0183 Interface Standard
The 'NMEA 0183 Interface Standard' defines electrical signal requirements; data transmission protocol and time; and specific data-sentence formats for a 4800-baud serial data bus. Each bus may have only one sender but many receivers.
The Latest Version Of This Standard Is Version 3.01 (released Jan. 2002).
There is also a high-speed addendum, NMEA 0183-HS Version 1.0, to Version 3.01 of NMEA 0183. This standard operates at a 38.4K-baud rate. Specific sentence formats are common to both NMEA 0183 and NMEA 0183-HS and are defined in the NMEA 0183.
GPS Devices And The NMEA 0183 Interface Standard
The Two Original GPS Consumer Product Developers In The United States First Chose To Add The NMEA 0183 Interface Standard Data Format To Their GPS Models, So The Systems Could Provide Position Information To Marine Autopilot Systems. Since Then, Garmin International And Various Other GPS System Manufactures, Now Provide The NMEA 0183 Interface As A Standard Option On Various GPS Models.
Because The NMEA 0183 Interface Standard Has Been Adopted And Available On GPS Systems, Most Program Developers Now Use This Interface Standard As The Universal GPS-Enabling Standard For Their Application Programs. This Means, A GPS System With The NMEA 0183 Interface Standard Will Be Supported By The Widest Range Of GPS-Enabled Software.
For A GPS To Use The NMEA 0183 Interface Standard, The GPS System Must Have A Serial Port. The NMEA 0183 Interface Standard Is Serial With A Baud Data Rate Of 4,800bps. Note A USB Interface Port Cannot Support This Standard! If GPS-Enabled Mapping Programs Are To Be Used, The Best Choice Is To Obtain A Serial Interfaced GPS System. A GPS System With A Serial Port And NMEA Support Will Provide The Most Universally Acceptable System. Out Of All The Manufactures And Brand Marketed Products, Garmin International's 'GARMIN' data interface format is the next best supported format in the field of GPS technology.
GPS User Benefits
Since The NMEA 0183 Interface Standard Is Now Made Available On Many GPS Models, Software Developers Have Now Adopted The 'NMEA 0183 Interface Standard' As The Universal Standard For Enabling Their Software To Work With Most Any GPS System. A Well Written GPS-Enabled Program Will Support The NMEA 0183 Interface Standard.
With A NMEA 0183 Or Newer Interface, A GPS Systems Can Send Detailed Data To Other Devices And Software Applications. A User Can Purchase A GPS-Enabled Mapping Program Or Navigation Program And Reap The Added Benefits Of Live Real-Time Moving Map Position Viewing, Navigation And Other Various Position Awareness Data; If Made Available In The Specific Application. There Are Many Applications Being Developed Today, With GPS-Enabled Features And Capabilities. For Example, The Exciting New Google Earth Online Earth Viewing Application. We Can Provide You With An Excellent Garmin GPS System Along With A Tool That Makes It Free To View Waypoints, Routes And Your Traveled Path On The Free Version Of Google Earth!
GPS Data Available
The NMEA 0183 Interface Standard Offers Several Different Data-Sentence Structure Options. Each Sentence Structure Offers Data Is A Different Order Or Types Of Data Sent. Some GPS-Enabled Mapping Programs Offers The User The Ability To Choose What NMEA Sentences To Use. One Of The Best Implementations Of This Technology Is In The 'ALL TOPO MAPS: GPS' Tool; Part Of A U.S.G.S. Mapping Application Suite With U.S. State Map Sets; Available Here.
With The 'All Topo Maps: GPS' Tool, NMEA Message Tracking May Be Turned 'On' And 'Off' For Each Individual NMEA Data Sentence.
'ALL TOPO MAPS: GPS' Features
> NMEA Sentence Selection For Real Time Tracking
The Commonly Supported NMEA Sentence Messages Are:
GGA ($GPGGA) GPS Position, Time And Fix
GLL ($GPGLL) Geographic Position - Latitude / Longitude
RMB ($GPRMB) Recommended Minimum Generic Navigation Information
RMC ($GPRMC) Transit Specific Output
> Typically Selecting 'RMC' Or 'RMB' Will Be Sufficient For Real-Time Position Tracking.
> 'Require Checksum on NMEA Sentences' - Use to perform a error-test on the incoming NMEA messages.
NMEA GPS Data Support Samples
Commonly Used NMEA Data-Sentences In Various GPS Brands/Models
$GPGGA Global positioning system fixed data
$GPGLL Geographic position - latitude / longitude
$GPGSA GNSS DOP and active satellites
$GPGSV GNSS satellites in view
$GPRMC Recommended minimum specific GNSS data
$GPVTG Course over ground and ground speed
Other NMEA Data-Sentences Used By Some Less Popular GPS Brands/Models
$GPALM GPS almanac data
$GPGRS GPS range residuals
$GPGST GPS pseudorange noise statistics
$GPMSS Beacon receiver status
$GPZDA UTC and local date/time data
GPS-Brand/Model-Specific Data-Sentences
Eagle AccuNav
Garmin 12XL, NMEA-0183 V 1.5
Garmin 12XL, NMEA-0183 V 2.0
Garmin GPS-38, NMEA-0183 V. 1.5 mode
Garmin GPS-38, NMEA-0183 V. 2.0 mode
Garmin GPS-45 (and probably GPS-40 and GPS-90)
Lowrance Global Map 100
Magellan Trailblazer
Trimble Ensign XL
Trimble Flightmate Pro and Scoutmaster
AutohelmSeatalk
GARMIN
NMEA 1083 Standard And USB
The NMEA 1083 Interface Standards Do Not Support USB. However, There Is A Solution To The Problem, If And Only If, The GPS Device Has The NMEA Serial Port! The Solution Can Be As Simple As Ordering One Of Our Three Tested GPS-SERIAL-To-USB Microcomputer Interfaces. A Special Interface In Required To Not Only Translate The Data Format But Also The Voltage Format! This Is Not A Simple Software Fix, And Cannot be Done With Just Software. The NMEA1083 Interface Standards Define The Use Of A Computer Industry Standard For A Serial Interface. This Standard Defines Voltage Levels, Cable Construction And Data Format; All OF Which Must Be Translated By Any Solution Offered. We Not Only Have The Simple Solution, But Three! Our Three Solutions Work Seamlessly With Microsoft Windows Desktop Based Application Software. The NMEA 1083 Was Defined Well Before The USB Standard Was Established And Today There Are Millions Of Devices In Use Using The NMEA 1083 Standards. A USB Port On The GPS Or On The Connecting Device Are Not Compatible With The NMEA 1083 Serial Interface Standard.
If A Modern Consumer Laptop/Notebook Computer Is Used, Most Models Today Will Require The Use Of One Of Our GPS-Serial-To-USB-Interface Microcomputer Interfaces. Our Microcomputer Based Interfaces Have Been Extensively Tested In Our Computer Technology Laboratory Over The Past 5 Years With Various GPS Systems, And Are Certified To Work With GPS Systems In The Field Or At The Desktop. These Microcomputer Interfaces Have A Tiny Microcomputer Along With An Automatic Loading Program, Which Translates The Incoming NMEA 0183 Interface Standard Sentences From The GPS-Serial Port, Into A Standard USB Protocol Format. Additionally, A Special Program (Called A Driver) Is Included. This Driver Program Constructs A Standard Windows Desktop Serial Port, So That All Programs Loaded In The PC System Can Access This Serial Port As If It Was A Real Physical Serial Port. Now With A GPS Connected Through Our Interface, The Windows Running Application Software Works As Normal, Connecting To The New Available 'Com' Port And Using The Incoming NMEA Data Sentences As Normal. Sweet!