### Install NetBSD Build Tools

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs pkgin, sets up the package repository, and installs Python 3.7, curses, and scons on NetBSD 8.1.

```bash
# export PKG_PATH=\"http://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/amd64/8.1/All\"
# pkg_add -v pkgin
# echo http://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/amd64/8.1/All > \
   /usr/pkg/etc/pkgin/repositories.conf
# pkgin update
# pkgin install python37 py37-curses
# ln -s /usr/pkg/bin/python3.7 /usr/pkg/bin/python
# ln -s /usr/pkg/bin/python3.7 /usr/pkg/bin/python3
# pkgin install py37-scons
# pkgin install ncurses
```

--------------------------------

### Install Homebrew and Dependencies (macOS)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs Homebrew package manager and then installs scons and asciidoctor using brew.

```bash
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
brew install scons asciidoctor
```

--------------------------------

### Get CFG-SIGNAL Configuration Items

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/ubxtool-examples.adoc

This example retrieves the current configuration for CFG-SIGNAL items in the RAM layer. It helps in understanding which signals are currently enabled or disabled.

```shell
$ ubxtool -g CFG-SIGNAL,0
[...] 
UBX-CFG-VALGET:
 version 1 layer 0 position 0
  layers (ram)
    item CFG-SIGNAL-GPS_L1CA_ENA/0x10310001 val 1
    item CFG-SIGNAL-GPS_L2C_ENA/0x10310003 val 1
    item CFG-SIGNAL-GAL_E1_ENA/0x10310007 val 1
    item CFG-SIGNAL-GAL_E5B_ENA/0x1031000a val 1
    item CFG-SIGNAL-BDS_B1_ENA/0x1031000d val 1
    item CFG-SIGNAL-BDS_B2_ENA/0x1031000e val 0
    item CFG-SIGNAL-QZSS_L1CA_ENA/0x10310012 val 1
    item CFG-SIGNAL-QZSS_L2C_ENA/0x10310015 val 1
    item CFG-SIGNAL-GLO_L1_ENA/0x10310018 val 1
    item CFG-SIGNAL-GLO_L2_ENA/0x1031001a val 1
    item CFG-SIGNAL-GPS_ENA/0x1031001f val 1
    item CFG-SIGNAL-GAL_ENA/0x10310021 val 1
    item CFG-SIGNAL-BDS_ENA/0x10310022 val 1
    item CFG-SIGNAL-QZSS_ENA/0x10310024 val 1
    item CFG-SIGNAL-GLO_ENA/0x10310025 val 1
    item CFG-SIGNAL-39/0x10310027 val 1
[...]

```

--------------------------------

### Minimal C client example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/libgps.adoc

A basic, fully functional C client example for interacting with gpsd. Refer to other gpsd client sources for more complex examples.

```c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <gps.h>

int main() {
    struct gps_data_t gps_data;
    int rc;

    // Open a connection to the GPSD daemon
    if (gps_open("localhost", "2947", &gps_data) == -1) {
        fprintf(stderr, "Failed to open GPSD connection: %s\n", gps_errstr(errno));
        return 1;
    }

    // Enable JSON reporting
    gps_stream(&gps_data, WATCH_JSON, NULL);

    printf("Waiting for GPS data...\n");

    // Loop to receive and process data
    while (1) {
        // Wait for data, with a timeout of 1 second
        if (gps_waiting(&gps_data, 1000000)) {
            // Read data from GPSD
            if (gps_read(&gps_data, NULL, NULL) == -1) {
                fprintf(stderr, "Error reading GPS data: %s\n", gps_errstr(errno));
                break; // Exit loop on error
            }

            // Check if we have a valid fix
            if (gps_data.set.gps_fix != 0) {
                printf("Time: %f, Latitude: %f, Longitude: %f, Altitude: %f\n",
                       gps_data.fix.time,
                       gps_data.fix.latitude,
                       gps_data.fix.longitude,
                       gps_data.fix.altitude);
            }
        } else {
            // Timeout occurred, no data received
            printf("No data received, continuing to wait...\n");
        }
    }

    // Close the connection to GPSD
    gps_close(&gps_data);
    return 0;
}

```

--------------------------------

### Install Git Core

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs git-core, which is required to build from a git repository.

```bash
# apt-get install git-core
```

--------------------------------

### Run gpsd with scons install

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Example of how to run gpsd after a minimal installation using 'scons install'. Use your GPS receiver's device file.

```bash
gpsd -n /dev/ttyACM0
```

--------------------------------

### Install Git, Build Tools, and Man Pages

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs essential tools for building from source and accessing man pages.

```bash
# apt-get install git-core
# apt-get install build-essential manpages-dev pkg-config
```

--------------------------------

### Clone, Build, and Install gpsd from Source

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Clones the gpsd repository, builds the software, runs checks, and installs it.

```bash
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons -c && scons && scons check && scons install
```

--------------------------------

### Build and Install GPSD (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Compiles the GPSD project using scons and then installs it.

```bash
scons
scons install
```

--------------------------------

### Install Qt Core and Network (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs Qt core and network modules for building a Qt compatible library.

```bash
emerge --noreplace dev-qt/qtcore dev-qt/qtnetwork
```

--------------------------------

### Install Optional PPS Tools (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs pps-tools for improved timing support, if needed.

```bash
emerge --noreplace net-misc/pps-tools
```

--------------------------------

### Install Optional Bluez (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs bluez for Bluetooth GPS device support.

```bash
emerge --noreplace net-wireless/bluez
```

--------------------------------

### Install Dependencies and Build gpsd on OpenBSD (Alternative)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs scons and git, creates a python link, and then proceeds with cloning and building gpsd.

```bash
# syspatch -c
# syspatch
# pkg_add -u
# pkg_add scons
# pkg_add git
# ln -s /usr/local/bin/python2 /usr/local/bin/python
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons --config=force && scons install
```

--------------------------------

### Install D-Bus Support (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs D-Bus support, a prerequisite for certain functionalities.

```bash
emerge --noreplace sys-apps/dbus
```

--------------------------------

### Install BC for Scons Check (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs the 'bc' utility, which is required by 'scons check'.

```bash
emerge --noreplace sys-devel/bc
```

--------------------------------

### Install GTK3 Development Files

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs development files for GTK3, required for running xgps and xgpsspeed.

```bash
# apt-get install python-gi-dev
# apt-get install libgtk-3-dev
```

--------------------------------

### Install Jessie Dependencies

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs necessary packages for building gpsd on Jessie.

```bash
# apt-get install scons libncurses5-dev python3 pps-tools
# apt-get install git-core
```

--------------------------------

### DEVICES Object Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsd_json.adoc

Example of a DEVICES object, listing available GPS devices and their drivers.

```json
{"class"="DEVICES","devices":[
    {"class":"DEVICE","path":"/dev/pts/1","flags":1,"driver":"SiRF binary"},
    {"class":"DEVICE","path":"/dev/pts/3","flags":4,"driver":"AIVDM"}]}
```

--------------------------------

### Install Optional Asciidoctor (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs asciidoctor for building man pages and HTML documentation.

```bash
emerge --noreplace dev-ruby/asciidoctor
```

--------------------------------

### Install Asciidoctor for Documentation

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs asciidoctor, a tool required for building gpsd documentation.

```bash
apt-get install asciidoctor
```

--------------------------------

### Build and Install gpsd from Source (Buster)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Builds and installs gpsd from source, forcing configuration if necessary.

```bash
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons --config=force && scons install
```

--------------------------------

### Install D-Bus Development Files

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs development files for D-Bus, enabling optional D-Bus connectivity for gpsd.

```bash
# apt-get install libdbus-1-dev
```

--------------------------------

### Install Optional Ncurses (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs ncurses for cgps and gpsmon utilities.

```bash
emerge --noreplace sys-libs/ncurses
```

--------------------------------

### Install Optional LibUSB (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs libusb for Garmin USB device support.

```bash
emerge --noreplace virtual/libusb
```

--------------------------------

### Install Core Build Tools (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs essential build tools like scons and git using the emerge package manager.

```bash
emerge --noreplace dev-build/scons dev-vcs/git
```

--------------------------------

### Install Debian Archive Keyring

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs the debian-archive-keyring package to resolve GPG key errors when adding backports repositories.

```bash
# apt-get install debian-archive-keyring
```

--------------------------------

### Install Optional PyGObject and PyCairo (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs pygobject and pycairo for xgps and xgpsspeed utilities on desktop systems.

```bash
emerge --noreplace dev-python/pygobject dev-python/pycairo
```

--------------------------------

### VERSION Object Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsd_json.adoc

Example of a VERSION object, reporting the gpsd daemon's release and API version.

```json
{"class":"VERSION","version":"2.40dev",
    "rev":"06f62e14eae9886cde907dae61c124c53eb1101f",
    "proto_major":3,"proto_minor":1
}
```

--------------------------------

### Install Documentation Build Tool

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs asciidoctor, a tool required for building gpsd documentation, which is a prerequisite for generating website HTML and source tarballs.

```bash
apt install asciidoctor
```

--------------------------------

### GPGSP Command Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/replacing-nmea.adoc

Example of a $GPGSP command to direct the receiver to emit specific sentences or return to NMEA-classic mode.

```nmea
$GPGSP,1*4E
```

--------------------------------

### Install libusb for Garmin Devices

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs libusb development files, required for some older Garmin USB devices.

```bash
# apt-get install libusb-1.0-0-dev
```

--------------------------------

### TOFF Object Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsd_json.adoc

Example of a TOFF (Timestamp Offset) object, reporting the difference between GPS time and system clock time at the start of a reporting cycle. Useful for understanding time synchronization.

```json
{"class":"TOFF","device":"/dev/ttyUSB0",
     "real_sec":1330212592, "real_nsec":343182,
     "clock_sec":1330212592,"clock_nsec":343184,
     "precision":-2}
```

--------------------------------

### Quick Start Build Commands

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

These commands are for building GPSD on Linux assuming all prerequisites are met. Run these as root.

```bash
su -
tar -xzf gpsd-X.YY.tar.gz
cd gpsd-X.YY
scons && scons check
```

```bash
# if that passes, and you want udev support, not recommended:
scons udev-install
```

--------------------------------

### Compile and Run gpsd Client

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/gpsd-client-example-code.adoc

Demonstrates how to download, compile, and run a basic C client for gpsd. This example connects to localhost on the default port and prints fix data. Use Ctrl+C to exit.

```bash
$ wget -o example1.c https://gpsd.io/example1.c.txt
$ gcc example1.c -o example1 -lgps -lm
$ ./example1
Fix mode: 3D (3) Time: 1615325173.000000000 Lat 44.068861 Lon -121.314085
Fix mode: 3D (3) Time: 1615325174.000000000 Lat 44.068861 Lon -121.314085
Fix mode: 3D (3) Time: 1615325175.000000000 Lat 44.068861 Lon -121.314085
^C
```

--------------------------------

### Start gpsd and ntpd

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/gpsd-time-service-howto.adoc

Sequence to start gpsd and ntpd for time synchronization. Ensure gpsd starts before ntpd for optimal clock resynchronization.

```bash
# killall -9 gpsd ntpd
# gpsd -n /dev/ttyXX
# sleep 2
# ntpd -gN
# sleep 2
# cgps
```

--------------------------------

### DPT Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/NMEA.adoc

Example of a Depth of Water sentence.

```nmea
$INDPT,2.3,0.0*46
```

--------------------------------

### Display gpsinit help message

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsinit.adoc

Shows a brief help text outlining the available options for the gpsinit command.

```bash
gpsinit -h
```

--------------------------------

### Check for gpsd packages on Debian Bullseye

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Command to query installed gpsd and libgps packages. Used to ensure no conflicting gpsd installations exist before installing from source.

```bash
# dpkg-query -l libgps* gpsd*
```

--------------------------------

### Prepare Source Directory and Build GPSD (macOS)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Creates a source directory, clones GPSD, and builds/installs it using scons.

```bash
# mkdir -p /usr/local/src/GPS
# cd /usr/local/src/GPS
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons && scons install
```

--------------------------------

### Build and Install gpsd on Debian Trixie

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

A comprehensive script to install prerequisites, clone, compile, and check gpsd on Debian Trixie. It assumes a fresh netinst installation.

```bash
#! /bin/bash

# A script to pull in the prerequisites for gpsd, pull it in, compile
# and exercise it. This script works on Debian Trixie as of May 12,
# 2025. As Trixie has not been released, it is a moving target.

# One thing this script does not do is check for and/or purge any
# Debian packages. We assume this is a freshly built system. Run
# "dpkg-query -l libgps* gpsd*" to see if there are any installed, and
# "apt purge" them.

# The location of the build directory. We will cd to this directory, 
# pull in the gpsd git repo, and then cd to the repo.
devel=~/versioned

apt update
apt upgrade                     # expect to be asked for approval.

# We take a kitchen sink approach to installing tools. If you want to
# pare down the installation, you can remove packages from this
# list.

# Gtk3 is only required to run xgps and xgpsspeed. You do not need a
# local X11 server installed, but it still pulls in a lot of packages.

# Ubxtool and zerk may optionally use the pyserial module for direct
# connection to the GNSS receiver.

# gpsplot uses matplotlib, which is in the package python3-matplotlib.

# pps-tools is for PPS timing.

# The documentation, including the web site, requires ascidoctor.

# manpages-dev is required for the man pages.

# Not included here: libusb-1.0-0-dev, for some very old Garmin USB devices.

# Everything else is required for a minimal build.

apt install -y asciidoctor build-essential gcc git libgtk-3-dev libncurses-dev \
   manpages-dev pkg-config pps-tools python-is-python3 python-gi-dev \
   python3-cairo-dev python3-gi-cairo python3-matplotlib python3-serial scons

mkdir -p $devel

# shellcheck disable=SC3044
cd $devel || { printf "Cd to %s failed.\n" $devel; exit 1;}

if [ ! -d gpsd ] ; then
    git clone https://gitlab.com/gpsd/gpsd.git
    cd gpsd || { printf "cd to %s failed.\n" $devel/gpsd; exit 1;}
else
    cd gpsd || { printf "cd to %s failed.\n" $devel/gpsd; exit 1;}
    git pull
fi

PYTHONPATH="$PYTHONPATH:/usr/local/lib/python3.13/dist-packages/"

scons -c && scons && scons check

# && scons install && scons udev-install

echo "\$PYTHONPATH" is "$PYTHONPATH"

if [ -d /etc/default ] && [ ! -e /etc/default/gpsd ] ; then

    cat > /etc/default/gpsd << DEFAULT
# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
DEVICES=""

# Other options you want to pass to gpsd
# GPSD_OPTIONS=""
GPSD_OPTIONS="--listenany"

# Automatically hot add/remove USB GPS devices via gpsdctl
USBAUTO="true"
DEFAULT
fi

printf "Enable listening on all interfaces in gpsd.socket if you want.\n";
```

--------------------------------

### Main Program Entry Point

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/internals.adoc

Initializes mutexes if 1PPS is compiled in, processes command-line options, and sets up the program for execution. Reads options to control internal variables and program behavior.

```c
int main(int argc, char *argv[])
```

--------------------------------

### Install Matplotlib for gpsplot

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs matplotlib, a dependency for the gpsplot program.

```bash
# apt install python3-matplotlib
```

--------------------------------

### Install Optional Matplotlib (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs matplotlib for the gpsplot utility.

```bash
emerge --noreplace dev-python/matplotlib
```

--------------------------------

### ntpshmmon Sample Report Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/ntpshmmon.adoc

This is an example of the beginning of a report file generated by ntpshmmon. It shows the version header followed by sample lines with various time synchronization data.

```text
ntpshmmon version 3.18
#      Name   Seen@                Clock                Real               L Pre
sample NTP2 1424926256.443030206 1424926256.115869233 1424926256.000000000 0  -1
sample NTP3 1424926256.443060517 1424926255.995430821 1424926256.000000000 0 -20
sample NTP3 1424926256.995747347 1424926256.995422728 1424926257.000000000 0 -20
sample NTP2 1424926257.112433572 1424926257.111936726 1424926257.000000000 0  -1
sample NTP3 1424926257.996221153 1424926257.995410232 1424926258.000000000 0 -20
sample NTP2 1424926258.107769409 1424926258.107451006 1424926258.000000000 0  -1
sample NTP3 1424926258.995647636 1424926258.995406476 1424926259.000000000 0 -20
```

--------------------------------

### GBS Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/NMEA.adoc

Example of a GPS Satellite Fault Detection sentence.

```nmea
$GPGBS,125027,23.43,M,13.91,M,34.01,M*07
```

--------------------------------

### Remove Existing gpsd Installation

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Stop the gpsd socket, disable it, and purge existing gpsd packages to ensure a clean installation. Some commands may report errors if gpsd is not installed.

```bash
$ sudo su -
# systemctl stop gpsd.socket
# systemctl disable gpsd.socket
# apt purge gpsd gpsd-clients gpsd-tools
```

--------------------------------

### Prepare Source Directory (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Creates a directory and navigates into it to store the GPSD source code.

```bash
mkdir -p /usr/local/src/GPSD
cd /usr/local/src/GPSD
```

--------------------------------

### xgps Help Option

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/xgps.adoc

Displays a summary of available options and exits.

```bash
xgps -? or xgps -h or xgps --help
```

--------------------------------

### GGA Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/NMEA.adoc

Example of a Global Positioning System Fix Data sentence.

```nmea
$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47
```

--------------------------------

### DTM Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/NMEA.adoc

Example of a Datum Reference sentence using the WGS84 datum.

```nmea
$GPDTM,W84,C*52
```

--------------------------------

### Install FreeBSD Build Tools

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs scons and git using the FreeBSD pkg command. Also includes commands to create Python symbolic links required by PEP394.

```bash
# pkg install scons
# pkg install git
# ln -s /usr/local/bin/python2.7 /usr/local/bin/python
# ln -s /usr/local/bin/python2.7 /usr/local/bin/python2
# ln -s /usr/local/bin/python3.6 /usr/local/bin/python3
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons --config=force && scons install
```

--------------------------------

### Display gpsinit version

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsinit.adoc

Prints the version information for the gpsinit utility.

```bash
gpsinit -v
```

--------------------------------

### Install Optional PySerial (Linux)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs pyserial for ubxtool and serial port support.

```bash
emerge --noreplace dev-python/pyserial
```

--------------------------------

### Install Dependencies and Build gpsd on OpenBSD

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs necessary packages like openssl, mozilla-rootcerts, and git, then clones and builds the gpsd project using scons.

```bash
# pkgin install openssl mozilla-rootcerts
# mozilla-rootcerts install
# pkgin install git
# git clone https://gitlab.com/gpsd/gpsd.git
# cd gpsd
# scons --config=force && scons install
```

--------------------------------

### Example ?WATCH Command with JSON

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/protocol-evolution.adoc

This command illustrates the new JSON-based protocol, allowing clients to specify message classes and receive reports from all devices. It demonstrates streaming all reports, setting raw mode, and dumping as pseudo-NMEA.

```text
?WATCH={"raw":true, nmea:true}
```

--------------------------------

### Install scons from Backports

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs the scons build tool version 2.3.0 or higher from the wheezy-backports repository.

```bash
apt-get -t wheezy-backports install scons
```

--------------------------------

### Install Python 2 GTK3 and Cairo Development Files (Buster)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs development files for Python 2 GTK3 and Cairo, required for xgps and xgpsspeed.

```bash
# apt-get install python-gi-dev python-cairo-dev
# apt-get install python-gobject-2-dev libgtk-3-dev
```

--------------------------------

### Start gpsd and chrony services

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/www/gpsd-time-service-howto.adoc

Preferred startup procedure when running as root. Ensures chronyd is running before gpsd and includes a brief sleep to allow services to initialize.

```shell
$ su -
# killall -9 gpsd chronyd
# chronyd -f /etc/chrony/chrony.conf
# sleep 2
# gpsd -n /dev/ttyXX
# sleep 2
# cgps
```

--------------------------------

### Install Python Serial Module (Buster)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs the pyserial module for direct connection to GNSS receivers.

```bash
# apt-get install python-serial
```

--------------------------------

### Install MacPorts Dependencies (macOS)

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/build.adoc

Installs scons, git, and asciidoctor using the MacPorts package manager.

```bash
# port install scons
# port install git
# port install asciidoctor
```

--------------------------------

### OSC Object Example

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsd_json.adoc

Example of an OSC (Oscillator) object, indicating the status of a disciplined local oscillator.

```json
{"class":"OSC","running":true,"device":"/dev/ttyUSB0",
    "reference":true,"disciplined":true,"delta":67}
```

--------------------------------

### gpxlogger command-line options

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpxlogger.adoc

Displays help information and exits. Use this to see all available options and their descriptions.

```bash
gpxlogger -h
```

--------------------------------

### Start gpsd for a specific serial device

Source: https://gitlab.com/gpsd/gpsd/-/blob/master/man/gpsd.adoc

Use this command as root to start the gpsd daemon, specifying the serial port device (e.g., /dev/ttyUSB0) to which the GPS receiver is connected. This is a common quick start method for Linux systems.

```bash
# gpsd /dev/ttyUSB0
```