Flight logging

How AuterionOS and the FMU log important information about a flight

General architecture

APX4 runs on the flight controller (FMU) and creates flight logs based on the SDLOG_<x> parameters, which can be configured via the ground station.

• With FMU storage (e.g., Skynode): Flight logs will write the logs to the FMU SD card.

• Without FMU storage (e.g., Skynode S): The FMU does not store any flight logs.

In both cases, the flight logs will be streamed to AuterionOS, where they are stored on the AuterionOS local storage and uploaded to Suite if the vehicle is registered and online.

AuterionOS logging

By default AuterionOS will request logging from the FMU as soon as the vehicle is armed. This behavior can be modified with the logging.log_from_boot System Parameter in the AuterionOS web interface.

• When the parameter is enabled: AuterionOS will request logging from the FMU on system boot.

• When the parameter is disabled: AuterionOS will request logging as soon as the vehicle is armed.

Once the FMU responds to the logging requests, AuterionOS stores the logs in the directory /data/log/flight-stack .

FMU logging

The configuration is described in the PX4 documentation: https://docs.px4.io/main/en/dev_log/logging.html. Note: Accessing the FMU's SD card requires opening the Skynode enclosure, which is not recommended due to potential warranty issues.