ultrasonic_monitor.ino: In function ‘void loop()’:
ultrasonic_monitor.ino:72:30: error: no matching function for call to ‘ros::Publisher::publish(plow_waypoint_nav::plow_ultrasonic&)’
ultrasonic_monitor.ino:72:30: note: candidate is:
In file included from /home/ustplow/sketchbook/libraries/ros_lib/ros/node_handle.h:83:0,
                 from /home/ustplow/sketchbook/libraries/ros_lib/ros.h:38,
                 from ultrasonic_monitor.ino:2:
/home/ustplow/sketchbook/libraries/ros_lib/ros/publisher.h:52:11: note: int ros::Publisher::publish(const ros::Msg*)
       int publish( const Msg * msg ) { return nh_->publish(id_, msg); };
           ^
/home/ustplow/sketchbook/libraries/ros_lib/ros/publisher.h:52:11: note:   no known conversion for argument 1 from ‘plow_waypoint_nav::plow_ultrasonic’ to ‘const ros::Msg*’