Added support for fixedrate mode

[mitchellwills]

Was tested with a Manta G-095C

[ahendrix]

It it not entirely obvious that the user should set the parameter described as "External triggering rate" when in fixed-rate mode.

What are your thoughts on adding another parameter which is explicitly the frame rate for fixed rate mode?

[mitchellwills]

I feel like a second parameter might be more confusing, especially when not using fixed rate mode. The description of trigger rate could be adjusted to make clear the meaning of this value in fixed rate mode

[mitchellwills]

Is there a reason why this was never implemented previously? Most of the code previously existed to make this function, but it was commented out.

[ahendrix]

I'm not sure why this wasn't implemented. I inherited the driver along with the rest of the PR2 stacks.

It looks like the driver has moved repositories a few times, and the original change logs have been lost to time...

I'm going to spend some time with the dynamic_reconfigure manual tonight and see if I can merge this and clean up the configuration a bit.

[trainman419]

It looks like we could use the dynamic_reconfigure groups API to hide some of the options that aren't related to the current streaming mode: http://wiki.ros.org/dynamic%20reconfigure/Reviews/7/1/11%20Groups%20API%20review%20API%20Review

[ahendrix]

I'm going to merge this and see if I can clean up the parameters.

[ahendrix]

I've refactored the configuration in c232a54 but I don't have a camera to test with. Can you give it a try for me?

[mitchellwills]

Sorry it took so long for me to get around to this.
I tried running with your new configuration, but I get the following in the console when using rqt_reconfigure
It looks like grouping was never actually implemented in rqt_reconfigure
ros-visualization/rqt_common_plugins#162

Traceback (most recent call last):
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 248, in _selection_changed_slot
    self._selection_selected(index_current, rosnode_name_selected)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 198, in _selection_selected
    item_widget = item_child.get_dynreconf_widget()
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/treenode_qstditem.py", line 148, in get_dynreconf_widget
    self._param_name_raw)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/dynreconf_client_widget.py", line 57, in __init__
    group_desc, node_name)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/param_groups.py", line 152, in __init__
    self._create_node_widgets(config)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/param_groups.py", line 198, in _create_node_widgets
    widget = eval(_GROUP_TYPES[group['type']])(self.updater, group)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_reconfigure/param_groups.py", line 247, in __init__
    super(BoxGroup, self).__init__(updater, config)
TypeError: __init__() takes exactly 4 arguments (3 given)