cps_rmp220_support/description/ros2_control.xacro

<?xml version="1.0"?>
<robot xmlns:xacro="http://www.ros.org/wiki/xacro">

    <xacro:unless value="$(arg sim_mode)">
        <ros2_control name="RealRobot" type="system">
            <hardware>
                <plugin>diffdrive_arduino/DiffDriveArduino</plugin>
                <param name="left_wheel_name">left_wheel_joint</param>
                <param name="right_wheel_name">right_wheel_joint</param>
                <param name="loop_rate">30</param>
                <param name="device">/dev/ttyUSB0</param>
                <param name="baud_rate">57600</param>
                <param name="timeout">1000</param>
                <param name="enc_counts_per_rev">3436</param>
            </hardware>
            <joint name="left_wheel_joint">
                <command_interface name="velocity">
                    <param name="min">-10</param>
                    <param name="max">10</param>
                </command_interface>
                <state_interface name="velocity"/>
                <state_interface name="position"/>
            </joint>
            <joint name="right_wheel_joint">
                <command_interface name="velocity">
                    <param name="min">-10</param>
                    <param name="max">10</param>
                </command_interface>
                <state_interface name="velocity"/>
                <state_interface name="position"/>
            </joint>
        </ros2_control>
    </xacro:unless>

    <xacro:if value="$(arg sim_mode)">
        <ros2_control name="GazeboSystem" type="system">
            <hardware>
                <plugin>gazebo_ros2_control/GazeboSystem</plugin>
            </hardware>
            <joint name="left_wheel_joint">
                <command_interface name="velocity">
                    <param name="min">-10</param>
                    <param name="max">10</param>
                </command_interface>
                <state_interface name="velocity"/>
                <state_interface name="position"/>
            </joint>
            <joint name="right_wheel_joint">
                <command_interface name="velocity">
                    <param name="min">-10</param>
                    <param name="max">10</param>
                </command_interface>
                <state_interface name="velocity"/>
                <state_interface name="position"/>
            </joint>
        </ros2_control>
    </xacro:if>

    <gazebo>
        <plugin name="gazebo_ros2_control" filename="libgazebo_ros2_control.so">
            <parameters>$(find cps_rmp220_support)/config/my_controllers.yaml</parameters>
            <parameters>$(find cps_rmp220_support)/config/gaz_ros2_ctl_use_sim.yaml</parameters>
        </plugin>
    </gazebo>

</robot>