vahid8/ros2-tuturial

Ros2-tuturial

Installation

1- Install ROS2-Humble & colcon(to build the packages) 2- Add it to enviromental variables

gedit ~/.bashrc
source /opt/ros/humble/setup.bash
source /usr/share/colcon_argcomplete/hook/colcon-argcomplete.bash

test it using 3 terminals

ros2 run demo_nodes_cpp talker
ros2 run demo_nodes_cpp listener
rqt_graph

creating working space and add it ot enviromental variables

mkdir ros2_ws
cd ros2_ws
mkdir src
colcon build # it will craete all necessary files and folders including setup.bash so you can run it using 
source ~/dev/ros2_ws/install/setup.bash

create ROS2 python package

cd src
ros2 pkg create my_robot_controler --build-type ament_python  (youc n also use ament_cmake)  --dependencies rclpy
cd ..
colcon build

add code to your package and run it

cd my_robot_controler/my_robot_controler
touch my_first_node.py
chmod +x my_first_node.py

#write your code inside my_first_node (check the example in this repo) first send second line should be #!/usr/bin/env python3 & import rclpy import Node class and inherit from that

run the code itself using ./myfirstnode To be able to run it on your ros2 run you need to add it to setup.py in section"entry_points" e.g sudo vim src/my_robotcontroler/setup.py entry_points={'console_scripts': ["test_node= my_robot_controler.my_first_node:main"],}

cd ~/dev/ros2_ws
colcon build
source ~./bashrc
ros2 run my_robot_controler test_node

if you dont want to type "colcon build" each time you make changes to your code you can type "colcon build --symlink-install" once

command list

Feature/Component	Description
ros2 node list	list of nodes
ros2 node info	get info
ros2 topic list	list of topics
ros2 topic info	get info
ros2 topic echo	see output of a publisher
ros2 topic hz	see frequency of publisher outputs
ros2 interface show	see data structure of input or output for the topic aftergetting the topic info
ros2 service list	list of services
ros2 service type	type of service
ros2 interface show	show data
rqt_qrt	show the gragh
colcon build	build project
colcon build --packages-up-to time_controler	build a specific package only
ros2 run time_controler nmea_subscriber
ros2 launch fixposition_driver_ros2 tcp.launch
create client. service, publisher, subsriber	different type of constructors

PTP

use installation here:// https://tsn.readthedocs.io/timesync.html#introduction//

1- check ethernets
ip link show
2- use ethtool to check if an eth send the ptp
ethtool -T <name from list above>
3- use this command
sudo ptp4l -i eno1 -f configs/gPTP.cfg --step_threshold=1 -m
4- get check_clocks.c and compile it (check if your pc clock is synchronized)
gcc -o check_clocks check_clocks.c
sudo ./check_clocks -d <name from list above>
Clocks on this system are synchronized :)