How to install and manage ulog debugging


How do we install the ulog library in Python? How do we use it? In the example created with the CLI, it contains the following line:

logger = logging.getLogger(‘main’)“Hello from miservicio”)

We have also added another one for further testing:


But no file .bin is generated in the missions-data/FDR directory

We’ve tried to copy the ulogpy folder from the github respository in our service proyect but no results.

Thank you!


ulog is installed by default on the drone, you don’t need to to anything to use it.

If you’re not seeing the logs from your mission in the missions-data/FDR directory, you check the following:

  • Is the AirSDK mission log settings properly enabled ? You can check and set this with FreeFlight.
  • Is your mission properly loaded (and/or activated) ? If you installed your mission without the --default flag, the mission will not be automatically loaded (see the mission lifecycle documentation for more informations).

Note that you can also see the logs live by enabling shell access on your drone, and using the live logging feature.


Hi Nicolas,

Will services activate automatically or I have to use --default flag too?

The behavior is the same for “Full missions” and “Service only”, so yes you will need to use either the --default flag, or a custom Olympe script to load it.

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