My_beginner_Tutorials

Overview

This Project contains a beginners tutorial of ROS2 Humble, specifically publishing and subscribibg to a topic.

Author

Keyur Borad (keyurborad5@gmail.com)

Prerequisites

• Ubuntu 22.04
• ROS2 Humble
• C++17 compatible compiler
• colcon build tool
• clang-format
• cpp-lint
• clang-tidy

Installation

1. Create a colon workspace

# After installing the ROS2 Humble Open terminal and source the ROS2 underlay
source /opt/ros/humble/setup.bash
# Create new directory
mkdir -p ~/ros2_ws/src
cd ~/ros2_ws/src

2. Clone the repository

#Clone the repository
git clone https://github.com/keyurborad5/my_beginner_tutorials.git

3. Check for missing dependencies and installing it

#go to ros2_ws directory
cd ..
rosdep install -i --from-path src --rosdistro humble -y

4. Build the workspace with colcon bubild

colcon build

5. Source Overlay

source install/setup.bash

Running the Package Nodes

1. Run the Publisher Node of the beginner_tutorials Package

ros2 run beginner_tutorials talker

2. Open another terminal and run the subcriber node

#source underlay
source /opt/ros/humble/setup.bash
# Got to the workspace directory
cd ~/ros2_ws
#source the overlay
source install/setup.bash
#Run the Subscriber node
ros2 run beginner_tutorials listener

Service Call To modify the string

ros2 service call /change_string beginner_tutorials/srv/ChangeString "{input: 'Lena'}"

Changing Parameters

Here we are changing the rate of publishing the custom message using the parameter

# Changinh the rate of publishing while starting the node using ros run
ros2 run beginner_tutorials talker --ros-args -p freq:=10.0
# Checking the parameter value
ros2 param get /my_publisher freq
# Set the parameter value
ros2 param set /my_publisher freq 1.0 

Launch file

ros2 launch beginner_tutorial pub_sub_launch.launch.py
#if want to start launcher with publisher rate
ros2 launch beginner_tutorial pub_sub_launch.launch.py freq:=2.0

Run TF Static Transform

# run the talker node
ros2 run beginner_tutorials talker
# Verify TF frames using
ros2 run tf2_ros tf2_echo world talk
# To create the TF tree PDF
ros2 run tf2_tools view_frames

To run level 2 integration test

cd ~/ros2_ws
# build the package
colcon build --packages-select beginner_tutorials
# ctest
colcon test --packages-select beginner_tutorials
# See the output results
cat log/latest_test/beginner_tutorials/stdout_stderr.log

To Record and play a bag for 15 sec

# run the launch file with ros bag enabled
ros2 launch beginner_tutorials pub_sub_launch.launch.py enable_bag_record:=true
# A ros bag will be generated in the results/recorded_bag directory
cd ~/ros_ws/src/my_beginner_tutorial/results/recorded_bag
ros2 bag play <name of the bag folder w/o brackets>
# to verify the recorded message (execute in another terminal)
ros2 run beginner_tutorials listerner
# execute in third terminal
ros2 topic echo /tf_static

Clang-Formating

cd ~/ros2_ws
#Clang-format 
clang-format -i --style=Google $(find . -name *.cpp -o -name *.hpp | grep -v "/build/")

Cpp-Lint

# go to your ros2 workspace directory
cd ~/ros2_ws/src
#Cpp Lint
cpplint --filter=-legal/copyright,-build/c++11,+build/c++17,-build/namespaces,-build/include_order $(find . -name *.cpp | grep -v "/build/")

Clang-tidy

cd ~/ros2_ws
# Build the workspace again with the camake args to generate compile_commands.jason file for Clang-tidy to work
colcon build --cmake-args -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
#Clang-tidy command
clang-tidy -p build/beginner_tutorials --extra-arg=-std=c++17 src/my_beginner_tutorials/src/*.cpp

Acknowledgement

• Open Source Robotics Foundation, Inc.
• ROS2 Community