Method parameter_event_callback

turtlebot3_node/src/turtlebot3.cpp:271–329

}

void TurtleBot3::parameter_event_callback()
{
  priv_parameters_client_ = std::make_shared<rclcpp::AsyncParametersClient>(this);
  while (!priv_parameters_client_->wait_for_service(std::chrono::seconds(1))) {
    if (!rclcpp::ok()) {
      RCLCPP_ERROR(this->get_logger(), "Interrupted while waiting for the service. Exiting.");
      return;
    }

    RCLCPP_WARN(this->get_logger(), "service not available, waiting again...");
  }

  auto param_event_callback =
    [this](const rcl_interfaces::msg::ParameterEvent::SharedPtr event) -> void
    {
      for (const auto & changed_parameter : event->changed_parameters) {
        RCLCPP_DEBUG(
          this->get_logger(),
          "changed parameter name : %s",
          changed_parameter.name.c_str());

        if (changed_parameter.name == "motors.profile_acceleration") {
          std::string sdk_msg;

          motors_.profile_acceleration =
            rclcpp::Parameter::from_parameter_msg(changed_parameter).as_double();

          motors_.profile_acceleration =
            motors_.profile_acceleration / motors_.profile_acceleration_constant;

          union Data {
            int32_t dword[2];
            uint8_t byte[4 * 2];
          } data;

          data.dword[0] = static_cast<int32_t>(motors_.profile_acceleration);
          data.dword[1] = static_cast<int32_t>(motors_.profile_acceleration);

          uint16_t start_addr = extern_control_table.profile_acceleration_left.addr;
          uint16_t addr_length =
            (extern_control_table.profile_acceleration_right.addr -
            extern_control_table.profile_acceleration_left.addr) +
            extern_control_table.profile_acceleration_right.length;

          uint8_t * p_data = &data.byte[0];

          dxl_sdk_wrapper_->set_data_to_device(start_addr, addr_length, p_data, &sdk_msg);

          RCLCPP_INFO(
            this->get_logger(),
            "changed parameter value : %f [rev/min2] sdk_msg : %s",
            motors_.profile_acceleration,
            sdk_msg.c_str());
        }
      }
    };

  parameter_event_sub_ = priv_parameters_client_->on_parameter_event(param_event_callback);