Getting started

Getting started may be the most challenging part of every new library. This guide is describing how to start with the library quickly and effectively

Download library

Library is primarly hosted on Github.

You can get it by:

  • Downloading latest release from releases area on Github

  • Cloning main branch for latest stable version

  • Cloning develop branch for latest development

Download from releases

All releases are available on Github releases area.

Clone from Github

First-time clone

This is used when you do not have yet local copy on your machine.

  • Make sure git is installed.

  • Open console and navigate to path in the system to clone repository to. Use command cd your_path

  • Clone repository with one of available options below

    • Run git clone --recurse-submodules https://github.com/MaJerle/lwgps command to clone entire repository, including submodules

    • Run git clone --recurse-submodules --branch develop https://github.com/MaJerle/lwgps to clone development branch, including submodules

    • Run git clone --recurse-submodules --branch main https://github.com/MaJerle/lwgps to clone latest stable branch, including submodules

  • Navigate to examples directory and run favourite example

Update cloned to latest version

  • Open console and navigate to path in the system where your repository is located. Use command cd your_path

  • Run git pull origin main command to get latest changes on main branch

  • Run git pull origin develop command to get latest changes on develop branch

  • Run git submodule update --init --remote to update submodules to latest version

Note

This is preferred option to use when you want to evaluate library and run prepared examples. Repository consists of multiple submodules which can be automatically downloaded when cloning and pulling changes from root repository.

Add library to project

At this point it is assumed that you have successfully download library, either cloned it or from releases page. Next step is to add the library to the project, by means of source files to compiler inputs and header files in search path

  • Copy lwgps folder to your project, it contains library files

  • Add lwgps/src/include folder to include path of your toolchain. This is where C/C++ compiler can find the files during compilation process. Usually using -I flag

  • Add source files from lwgps/src/ folder to toolchain build. These files are built by C/C++ compiler. CMake configuration comes with the library, allows users to include library in the project as subdirectory and library.

  • Copy lwgps/src/include/lwgps/lwgps_opts_template.h to project folder and rename it to lwgps_opts.h

  • Build the project

Tip

If you are using CMake build system, you can add the library to the project by adding the library’s folder directory with add_directory() CMake command, followed by linking the target with target_link_libraries()

Configuration file

Configuration file is used to overwrite default settings defined for the essential use case. Library comes with template config file, which can be modified according to the application needs. and it should be copied (or simply renamed in-place) and named lwgps_opts.h

Note

Default configuration template file location: lwgps/src/include/lwgps/lwgps_opts_template.h. File must be renamed to lwgps_opts.h first and then copied to the project directory where compiler include paths have access to it by using #include "lwgps_opts.h".

Tip

If you are using CMake build system, define the variable LWGPS_OPTS_DIR before adding library’s directory to the CMake project. Variable must set the output directory path. CMake will copy the template file there, and name it as required.

Configuration options list is available available in the Configuration section. If any option is about to be modified, it should be done in configuration file

Template configuration file
 1/**
 2 * \file            lwgps_opts_template.h
 3 * \brief           LwGPS configuration file
 4 */
 5
 6/*
 7 * Copyright (c) 2023 Tilen MAJERLE
 8 *
 9 * Permission is hereby granted, free of charge, to any person
10 * obtaining a copy of this software and associated documentation
11 * files (the "Software"), to deal in the Software without restriction,
12 * including without limitation the rights to use, copy, modify, merge,
13 * publish, distribute, sublicense, and/or sell copies of the Software,
14 * and to permit persons to whom the Software is furnished to do so,
15 * subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
22 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
23 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
24 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
25 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
26 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27 * OTHER DEALINGS IN THE SOFTWARE.
28 *
29 * This file is part of LwGPS - Lightweight GPS NMEA parser library.
30 *
31 * Author:          Tilen MAJERLE <tilen@majerle.eu>
32 * Version:         v2.2.0
33 */
34#ifndef LWGPS_OPTS_HDR_H
35#define LWGPS_OPTS_HDR_H
36
37/* Rename this file to "lwgps_opts.h" for your application */
38
39/*
40 * Open "include/lwgps/lwgps_opt.h" and
41 * copy & replace here settings you want to change values
42 */
43
44#endif /* LWGPS_OPTS_HDR_H */

Note

If you prefer to avoid using configuration file, application must define a global symbol LWGPS_IGNORE_USER_OPTS, visible across entire application. This can be achieved with -D compiler option.

Minimal example code

To verify proper library setup, minimal example has been prepared. Run it in your main application file to verify its proper execution

Absolute minimum example
 1/**
 2 * This example uses direct processing function
 3 * to process dummy NMEA data from GPS receiver
 4 */
 5#include <string.h>
 6#include <stdio.h>
 7#include "lwgps/lwgps.h"
 8
 9/* GPS handle */
10lwgps_t hgps;
11
12/**
13 * \brief           Dummy data from GPS receiver
14 */
15const char gps_rx_data[] = ""
16                           "$GPRMC,183729,A,3907.356,N,12102.482,W,000.0,360.0,080301,015.5,E*6F\r\n"
17                           "$GPRMB,A,,,,,,,,,,,,V*71\r\n"
18                           "$GPGGA,183730,3907.356,N,12102.482,W,1,05,1.6,646.4,M,-24.1,M,,*75\r\n"
19                           "$GPGSA,A,3,02,,,07,,09,24,26,,,,,1.6,1.6,1.0*3D\r\n"
20                           "$GPGSV,2,1,08,02,43,088,38,04,42,145,00,05,11,291,00,07,60,043,35*71\r\n"
21                           "$GPGSV,2,2,08,08,02,145,00,09,46,303,47,24,16,178,32,26,18,231,43*77\r\n"
22                           "$PGRME,22.0,M,52.9,M,51.0,M*14\r\n"
23                           "$GPGLL,3907.360,N,12102.481,W,183730,A*33\r\n"
24                           "$PGRMZ,2062,f,3*2D\r\n"
25                           "$PGRMM,WGS84*06\r\n"
26                           "$GPBOD,,T,,M,,*47\r\n"
27                           "$GPRTE,1,1,c,0*07\r\n"
28                           "$GPRMC,183731,A,3907.482,N,12102.436,W,000.0,360.0,080301,015.5,E*67\r\n"
29                           "$GPRMB,A,,,,,,,,,,,,V*71\r\n";
30
31int
32main() {
33    /* Init GPS */
34    lwgps_init(&hgps);
35
36    /* Process all input data */
37    lwgps_process(&hgps, gps_rx_data, strlen(gps_rx_data));
38
39    /* Print messages */
40    printf("Valid status: %d\r\n", hgps.is_valid);
41    printf("Latitude: %f degrees\r\n", hgps.latitude);
42    printf("Longitude: %f degrees\r\n", hgps.longitude);
43    printf("Altitude: %f meters\r\n", hgps.altitude);
44
45    return 0;
46}