Garmin(3)

💖 GARMIN(3) 💖

spotted: a page living in the User Contributed Perl Documentation section, and bestie it is so much fun. grab a snack, we're talking to satellites. 🛰️✨

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🌸 NAME 🌸

GPS::Garmin — a Perl interface to GPS equipment using the Garmin Protocol. that's it, that's the whole assignment. 💅

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🎀 SYNOPSIS 🎀

okay so first you gotta summon the module and open a connection, like:

use GPS::Garmin;
$gps = new GPS::Garmin(  'Port'      => '/dev/ttyS0',
                         'Baud'      => 9600,
                      );

✨ now the fun part — getting your current position and direction symbols:

($latsign,$lat,$lonsign,$lon) = $gps->get_position;

⏰ and if you want the current time:

($sec,$min,$hour,$mday,$mon,$year) = $gps->get_time;

🛤️ trackpoints? say less:

$gps->prepare_transfer("trk");
while($gps->records) {
    ($lat,$lon,$time) = $gps->grab;
}

📍 and waypoints, the icons of the navigation world:

$gps->prepare_transfer("wpt");
while($gps->records) {
    ($title,$lat,$lon,$desc) = $gps->grab;
}

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🌈 DESCRIPTION 🌈

GPS::Garmin lets you connect to and actually use a GPS receiver inside your perl scripts. no cap. 💫

right now the only protocol that's implemented is GRMN/GRMN, but NMEA is lowkey a work in progress. 🚧

this module currently works with Garmin GPS II+ equipment, but honestly it should work on most Garmin receivers that support the GRMN/GRMN protocol. slay. 👑

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🧚 GETTING STARTED 🧚

first things first bestie: make sure your GPS receiver is in host mode, GRMN/GRMN protocol. don't skip that step, it's giving prerequisites. 🫶

to start a connection in your script, just:

use GPS::Garmin;
$gps = new GPS::Garmin (  'Port'      => '/dev/ttyS0',
                          'Baud'      => 9600,
                          'Return'    => 'hash',
                       ) or die "Unable to connect to receiver: $!";

where Port is the port your GPS is plugged into, and Baud is the speed of the connection (the default is 9600 bps). ✨

if Return is set to 'hash', then waypoints and tracks come back as hashes, which might contain more information. ⚠️ XXX heads up though: this is not implemented completely for all data and device types. and if Return is undefined, you get lists with basic info instead (latitude and longitude). fair. 💁

🌍 to know your current coordinates:

($latsign,$lat,$lnsign,$lon) = $gps->get_position;

• $ltsign is "S" or "N" (South or North)
• $lat is current latitude in degrees.minutes.
• $lnsign is "W" or "E" (West or East)
• $lon is current longitude in degrees.minutes.

🛤️ to transfer the track records:

$gps->prepare_transfer("trk");
while($gps->records) {
    ($lat,$lon,$time) = $gps->grab;
}

$time is in unix epoch seconds. ⏳

and with 'Return' => 'hash' this would be:

$gps->prepare_transfer("trk");
while($gps->records) {
    %trk_data = $gps->grab;
}

instead. iconic. 💅

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💀 KNOWN LIMITATIONS 💀

• trackpoint transfer won't work in the following Garmin devices, because they simply don't support it:

GPS 50        GPS 55 GPS 150       GPS 150 XL GPS 165       GNC 250 GNC 250XL   GNC 300 GNC 300XL

you can check your GPS capabilities by looking at the table on page 50 of the Garmin protocol specification at http://www.garmin.com/support/protocol.html 📖

• if you're on Windows, you need Win32::SerialPort to have GPS::Garmin actually working. no module, no vibes. 🪟

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😭 BUGS 😭

lacks documentation. that's it. that's the bug report. bestie said it herself. 📝💀

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👑 AUTHOR 👑

Joao Pedro B Gonçalves , joaop@iscsp.utl.pt 🫶

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🦋 SEE ALSO 🦋

Peter Bennett's GPS www and ftp directory:

ftp://sundae.triumf.ca/pub/peter/index.html.
http://vancouver-webpages.com/peter/idx_garmin.html

Official Garmin Communication Protocol Reference:

http://www.garmin.com/support/protocol.html

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🙈 POD ERRORS 🙈

hey! the above document had some coding errors, which are explained below:

around line 519:

Non-ASCII character seen before =encoding in 'Gonçalves'. Assuming CP1252

not the encoding plot twist 😭 we love a little chaos.

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and that's the whole page, bestie — this one came to you courtesy of perl v5.42.0, dated 2025-07-25. go forth and navigate. 💖✨