Before and after. I figured out how to do build the client configuration from reference. This moves the XML from program flash of ardupilot to disk of offboard computer.
Before
Target Text (B) Data (B) BSS (B) Total Flash Used (B) Free Flash (B)
--------------------------------------------------------------------------------------
bin/antennatracker 3009746 116733 197192 3126479 Not Applicable
bin/arducopter 3954606 170173 215048 4124779 Not Applicable
bin/arducopter-heli 3943934 171693 216136 4115627 Not Applicable
bin/arduplane 3874086 172525 212776 4046611 Not Applicable
bin/ardusub 3501974 138877 207752 3640851 Not Applicable
bin/blimp 2822538 109845 197288 2932383 Not Applicable
bin/ardurover 3611312 151877 213704 3763189 Not Applicable
After
BUILD SUMMARY
Build directory: /home/ryan/Documents/ardu_ws/src/ardupilot/build/sitl
Target Text (B) Data (B) BSS (B) Total Flash Used (B) Free Flash (B)
--------------------------------------------------------------------------------------
bin/antennatracker 3009258 116733 197192 3125991 Not Applicable
bin/arducopter 3954150 170173 215048 4124323 Not Applicable
bin/arducopter-heli 3943446 171693 216136 4115139 Not Applicable
bin/arduplane 3873598 172525 212776 4046123 Not Applicable
bin/ardusub 3501486 138877 207752 3640363 Not Applicable
bin/blimp 2822018 109845 197288 2931863 Not Applicable
bin/ardurover 3610824 151877 213704 3762701 Not Applicable
For arducopter, it was 456 bytes difference for the one message. Considering px4_msgs has 184 different messages, if this was extrapolated out very roughly, that’s an 83.9KB saving. I don’t think there is any reason a ROS developer would need access to 184 different topics to do offboard control, but you never know I guess.
Huge!