A homemade mecanum wheels based robot car, running Robot OS on a Raspberry Pi, with an additional STM32 board, dedicated to motors & making possible to drive the car with a PS2 controller.

This repository gathers the Raspberry Pi files, a.k.a. the ROS car application (RCAP).

Install Ubuntu Mate 20.04.3 LTS (a.k.a. Focal Fossa)

Update Ubuntu & add some regular tools

• sudo apt-get update
• sudo apt-get upgrade
• sudo apt-get install vim pyyaml
• sudo apt-get install libssl-dev
• sudo apt-get install i2c-tools libi2c-dev smbus
• sudo apt-get install curl gnupg2 lsb-release
• sudo apt-get install libpython3-dev python3-pip
• sudo pip3 install transforms3d

Setup a local network between the robot car and local Windows PC

• sudo ufw disable
• sudo ifconfig enp0s8 192.168.1.45
• sudo route add default gw 192.168.1.254 enp0s8
• sudo /etc/init.d/networking restart

Setup SSH

• sudo apt-get openssh-server

Setup VNC

• sudo apt-get install tightvncserver

• tightvncserver

Enter and confirm password Enter no view-only password

• sudo vim /etc/systemd/system/tightvncserver.service

[Unit] Description=TightVNC remote desktop server
After=sshd.service

[Service] Type=dbus ExecStart=/usr/bin/tightvncserver :1 User=pi Type=forking

[Install] WantedBy=multi-user.target

• sudo chown root:root /etc/systemd/system/tightvncserver.service
• sudo chmod 755 /etc/systemd/system/tightvncserver.service
• sudo systemctl start tightvncserver.service
• sudo systemctl status tightvncserver.service
• sudo systemctl enable tightvncserver.service

Setup serial port

• sudo systemctl disable hciuart

• sudo systemctl disable hciuart.service

• sudo systemctl disable bluetooth.service

• sudo systemctl stop serial-getty@ttyS0.service

• sudo systemctl disable serial-getty@ttyS0.service

• sudo systemctl mask serial-getty@ttyS0.service

• sudo usermod -a -G dialout pi

• sudo usermod -a -G tty pi

• sudo vim /boot/firmware/usercfg.txt

enable_uart=1 dtoverlay=disable-bt

• sudo vim /boot/firmware/cmdline.txt

Remove any "console=ttyAMA0,115200", if found

Install ROS2

• sudo apt-get install locales

• sudo locale-gen en_US en_US.UTF-8

• sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8

• export LANG=en_US.UTF-8

• locale

• sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

• echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/ros2.list > /dev/null

• sudo apt-get update

• sudo apt-get install python3-rospkg

• sudo apt-get install ros-galactic-desktop

• sudo apt-get install ros-galactic-teleop-twist-keyboard

• sudo apt-get install ros-galactic-tf2-tools ros-galactic-tf-transformations

• echo "source /opt/ros/galactic/setup.bash" >> ~/.bashrc

• source ~/.bashrc

• rosversion --distro

• ros2 doctor --report

• ros2 run demo_nodes_cpp talker &

• ros2 run demo_nodes_cpp listener &

• killall talker listener

Setup & try LIDAR

• ls -l /dev | grep ttyUSB

• sudo chmod 666 /dev/ttyUSB0

• git clone https://github.com/Slamtec/rplidar_ros.git

• cd rplidar_ros

• git checkout ros2

• colcon build --symlink-install

• source install/setup.bash

• ros2 run tf2_ros static_transform_publisher 0 0 0 0 0 0 map laser &

• ros2 launch rplidar_ros view_rplidar.launch.py &

• rviz2 -d rviz/rplidar_ros2.rviz

Try & calibrate MPU9250 IMU

• i2cdetect -y 1

• cd tools

• python3 calibrate_imu.py

Install Navigation2 (Nav2)

• sudo apt-get install ros-galactic-navigation2

• sudo apt-get install ros-galactic-nav2-bringup

• sudo apt-get install ros-galactic-slam-toolbox

• sudo apt-get install ros-galactic-robot-localization

• sudo apt-get install ros-galactic-joint-state-publisher-gui

• sudo apt-get install ros-galactic-rqt-robot-steering

• sudo apt-get install ros-galactic-xacro

• ros2 launch rcap rcap.vm.display.launch.py

• rviz2 -d config.simulation.rviz

• ros2 launch slam_toolbox online_async_launch.py

• ros2 launch nav2_bringup navigation_launch.py

• ros2 launch nav2_bringup navigation_launch.py params_file:=/home/stef/RCAP/robot_car/config/nav2.simulation.yaml

• ros2 run nav2_costmap_2d nav2_costmap_2d_markers voxel_grid:=/local_costmap/voxel_grid visualization_marker:=/my_marker

• rqt_robot_steering --force-discover

• ros2 run teleop_twist_keyboard teleop_twist_keyboard

• ros2 topic pub /goal_pose geometry_msgs/PoseStamped '{header: {stamp: {sec: 0, nanosec: 0}, frame_id: "map"}, pose: {position: {x: 1.0, y: 0.0, z: 0.0}, orientation: {w: 1.0}}}' -1

• ros2 topic echo /goal_pose

Commands found usefull while learning/testing

• ros2 run joint_state_publisher_gui joint_state_publisher_gui description/robot_car.urdf

• ros2 run tf2_ros static_transform_publisher 0 0 0 3.14 0 0 base_link lidar_link

• ros2 run teleop_twist_keyboard teleop_twist_keyboard

• rqt_graph

• ros2 run tf2_tools view_frames

• xdg-open frames.pdf

• sudo service apport stop