Pacpus tutorials

Foreword

Before reading these tutorials, please have a look at the GettingStarted page in order to install the framework.

Don't forget to check that the environment variable PACPUS_ROOT is well defined in your setup.

The repository containing the tutorials is accessible through the URL in this command:

cd ~
mkdir dev && mkdir pacpus
cd dev/pacpus
svn co https://devel.hds.utc.fr/svn/pacpustutorials

The repository contains several folders:

• template: you will find here some source codes (CMakeLists.txt, .cpp and .h) useful for the exercises.
• exercises: the wording of each tutorial. The wordings are available below too.
• solutions: the solutions of the exercises (coming soon)

Basic Concepts

Tutorial n°1: Creating your first PAPCUS project

The objective of this exercise is to understand the build process of a PACPUS project. The utility 'cmake' is used to create the Makefile of the project, and finally we use the GNU Compiler Collection to build the plugins.

Goal of this exercise:
Thanks to the different source codes (.cpp, .h and CMakeLists.txt) in the folder 'template', create a new PACPUS project containing just 1 component.
This component may generate a message in the terminal at a user selectable frequency.

Once you have built your plugin, run it in /opt/pacpus/x.y.z/bin folder with the PacpusSensor executable.

Indications:

• You can use QTimer to generate the timer.
• A component can be parametrized in a XML file, it might be useful to change the message display frequency.
• The tree of your project may be something like that:

pacpustutorials
   |
   |--> project_exercises
           |
           |--> plugin_exercise_1
                    |
                    |--> CMakeLists.txt
                    |--> MessageComponent.h
                    |--> MessageComponent.cpp
           |
           |--> build
                    |
                    |--> build_linux.sh
           |
           |--> CMakeLists.txt

Tutorial n°2: Managing the communication of components

Exercise 2.1: communication between components

In this exercise we will develop a new component with one input and one output. The component should add a specific number defined as a parameter to the input value and provide the result as output. Before sending the result on the output it must wait for 1 second. The component will print to the terminal the result of the addition too.

Write the code of this component in a new plugin but use the same pacpus project as the exercise 1. Build and install the plugin in the PACPUS_ROOT/bin folder and execute the plugin with the PacpusSensor application.

Indication:

• Now, the tree of your project may be something like that:

pacpustutorials
   |
   |--> project_exercises
           |
           |--> plugin_exercise_1
                    |
                    |--> CMakeLists.txt
                    |--> MessageComponent.h
                    |--> MessageComponent.cpp
           |
           |--> plugin_exercise_2
                    |
                    |--> CMakeLists.txt
                    |--> AdditionComponent.h
                    |--> AdditionComponent.cpp
           |
           |--> build
                    |
                    |--> build_linux.sh
           |
           |--> CMakeLists.txt

Exercise 2.2: communication of variable size data

Create a new component in the same plugin as the previous one (exercise 2.1). It will have the same functionnality with the difference that it can do an addition on a vector of input values.

Build, install and run this new component.

Indication :

• you can use the QVector class as input/output type.

Exercise 2.3: Threaded component

From the component written in exercise 2.2 create a new component with the same interface. The addition must be done in a separate thread.

Build, install and run this new component.

Indication :

• Your component must inherit from the QThread class.
• Take care of the protection of the data to guarantee a thread safe execution.

Advanced concepts

Soon available...