Development Notes

A document dedicated to important and helpful information related to adding functionality to this toolbox.

Adding a Physical Control Element

Anything that controls a physical element of the robot (e.g. wheel motors, on board servos) should be implemented as a ROS action service. Actions that interfere with each other (drive forward, turn left, etc.) should be implemented as multiple actions on one action service. This allows for new actions to preempt old actions (stop moving forward if I am now telling you to turn left). If the physical control element should belong to an already existing ROS action service, then add it to that service, following the instructions in Adding a New Action to an Existing ROS Action Service. If there is no existing section suitable for the action you want to implement, follow the instructions in Writing a ROS Action Service.

Currently implemented ROS action services:

Drive Control Service

Adding a New Action to an Existing ROS Action Service

Writing a ROS Action Service

Link to instructions online
I would use the above example to gain insite into what each part does, and use the Drive Control Service as a template for new action servers
Make sure to include message file like so from sphero_msgs.msg import DriveRawMotorsAction

Writing Custom ROS Aciton Messages

Link to instructions online
Project convention means this file should be in ‘sphero_toolbox/catkin_ws/src/sphero_msgs/action’

Generating Matlab Messages from Custom ROS Action Messages

This step did not work on my mac, but did work on my linux machine. It still works to copy the generated files over to my Mac system and use them there.

Instructions for importing custom messages into Matlab
1. Ensure you have the “ROS Toolbox Interface for ROS Custom Messages”
2. Make sure the most recent version of sphero_msgs is in the directory msg_gen
1. In the terminal, navigate to sphero_toolbox/catkin_ws/src
2. cp -r sphero_msgs ../../msg_gen/
  1. Remove old Matlab generated messages
3. In the terminal, navigate to sphero_toolbox/msg_gen
4. Execute the command: rm -r matlab_gen
  1. In Matlab, navigate to sphero_toolbox
  2. In the Matlab command window execute the command: rosgenmsg('msg_gen')
  3. Rerun the script “configure_installation.m”
  4. Restart Matlab
  5. You can use rosmsg list and rosmsg info <new or altered message> to make sure the new or changed messages are recognized