Apply suggestions from code review

Author: destogl

ros2_control_demo_hardware/ros2_control_demo_hardware.xml

@@ -17,7 +17,7 @@
          type="ros2_control_demo_hardware::DiffBotSystemHardware"
          base_class_type="hardware_interface::SystemInterface">
     <description>
-      The ROS2 Control minimal robot protocol. This is example for start porting the robot from ROS 1.
+      The ros2_control DiffBot example using a system hardware interface-type. It uses velocity command and position state interface. The example is the starting point to implement a hardware interface for differential-drive mobile robots.
     </description>
   </class>
 </library>

ros2_control_demo_hardware/src/diffbot_system.cpp

@@ -1,4 +1,4 @@
-// Copyright 2020 ros2_control Development Team
+// Copyright 2021 ros2_control Development Team
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -118,7 +118,6 @@ DiffBotSystemHardware::export_command_interfaces()
   return command_interfaces;
 }
 
-
 return_type DiffBotSystemHardware::start()
 {
   RCLCPP_INFO(
@@ -215,7 +214,6 @@ hardware_interface::return_type ros2_control_demo_hardware::DiffBotSystemHardwar
 }  // namespace ros2_control_demo_hardware
 
 #include "pluginlib/class_list_macros.hpp"
-
 PLUGINLIB_EXPORT_CLASS(
   ros2_control_demo_hardware::DiffBotSystemHardware,
   hardware_interface::SystemInterface

ros2_control_demo_robot/controllers/diffbot_diff_drive_controller.yaml

@@ -4,14 +4,14 @@ controller_manager:
 
     joint_state_controller:
       type: joint_state_controller/JointStateController
+
     diffbot_base_controller:
       type: diff_drive_controller/DiffDriveController
 
 diffbot_base_controller:
   ros__parameters:
     left_wheel_names: ["left_wheel_joint"]
     right_wheel_names: ["right_wheel_joint"]
-    #write_op_modes: ["motor_controller"]
 
     wheel_separation: 0.10
     #wheels_per_side: 1  # actually 2, but both are controlled by 1 signal
@@ -63,4 +63,5 @@ diffbot_base_controller:
     angular.z.max_acceleration: 1.0
     angular.z.min_acceleration: -1.0
     angular.z.max_jerk: 0.0
-    angular.z.min_jerk: 0.0
+    angular.z.min_jerk: 0.0
+