gpsd2ecal

1. About

• Gps car trajectory
• gpsd2ecal messages

2. Getting started

• Install the dependencies
• How to build
• How to use it
• Program settings

About

Gpsd2ecal is a tool which collects GPS information on Linux based systems and sends it to eCAL via Google protobuf messages.

The project does not provide any driver, but instead it uses the Linux opensource tool gpsd (gps-daemon) which contains drivers for any GPS device like for e.g Ublox or built-in GPS cards. Here you can find a list of compatible receivers.

Given the fact that gpsd is widespread, the gpsd2ecal will have the same "coverage", with no other dependencies involved.

Also, gpsd2ecal is designed in a way that provides a lot of flexibility to extend it and adapt it to the user needs.
This means that one could implement custom messages within gpsd2ecal just by:

• adding a new proto file
• and a new C++ class that maps the information for eCAL.

If the user wants to collect data from a different driver, then the one provided by the gpsd, this is also possible by a separate implementation of Idevice interface within gpsd2ecal, without changing the project structure.

Gps car trajectory

The below trajectory was displayed using a kml viewer. Data acquisition was done with an U-blox 6 receiver and eCAL Recorder to record the sent data.

gpsd2ecal messages

After you have created the measurements, you can replay the data using the eCAL Player and view it with eCAL Monitor.

Getting started

Install the dependencies for Ubuntu 18.04:

1. Install eCAL and follow the setup steps
2. Run the below commands:

---

sudo apt-get update
sudo apt-get install cmake libprotobuf-dev protobuf-compiler libprotoc-dev libprotoc10  
sudo apt-get install gpsd-clients gpsd libgps-dev

Install the dependencies for Ubuntu 20.04:

1. Install eCAL and follow the setup steps
2. Run the below commands:

---

sudo apt-get update
sudo apt-get install cmake libprotobuf-dev protobuf-compiler libprotoc-dev build-essential
sudo apt-get install gpsd-clients gpsd libgps-dev

How to build:

• to also initialize, fetch and checkout any nested submodules, run in a terminal git submodule update --init --recursive
• run make_all.sh from the build_scripts folder.

How to use it:

Simply run the gpsd2ecal application.

You can see the menu information by running the following command ./gpsd2ecal --h :

Parameters: 
--h            --help           Display this help 
--i PATH       --ini PATH       Use the path to an ini file to load the settings. 

To see sent messages to eCAL just type in a terminal ecal_mon_gui to open eCAL Monitor.

How to initialize the program settings:

You can edit the gps2ecal.ini file to change the settings of the program. There are two sections:

• general: refers to the eCAL message settings
• gpsd : refers to the gpsd port and address

[general]

Here it is possible to change the gps source and the frequency of the sent out messages, but also possible to set the already existing publishers you want to use and add new ones. But keep in mind that if new publisher are added the gpsd2ecal code must be extended.

; ecal publishers
gps2ecal_full = true
gps2ecal_reduced = true 

In the following section the user can set the topic name:

; ecal messages
gps2ecal_full_name = Gpsd2eCalFull
gps2ecal_reduced_name = Gpsd2eCalReduced

[gpsd]

The GPS receivers are attached to a host computer through serial or USB ports and this makes the data available on TCP port 2947. The user can change this settings, if required, in the below code block:

; address: 127.0.0.1
; address: localhost
; address on which gpsd can be reached
address = 127.0.0.1

; port:
; port on which gpsd can be reached
port = 2947