Pixhawk 2 dataflash logs documentation?

Assuming this is pixhawk not arducopter related.

I am trying to find the documentation for the dataflash logs - this page (http://ardupilot.org/copter/docs/common-downloading-and-analyzing-data-logs-in-mission-planner.html#message-details-copter-specific) is helpful, but many of the parameters it talks about are not available or different in the pixhawks logs, and there are many data items the pixhawk is logging which do not appear to be documented.

Is this information available anywhere?

Also, in the short term, can anyone explain the difference between, ThI, ThO, ThH?


Hi Guy,

This isn’t Pixhawk related, but ArduPilot related as the logging is done by ArduPilot. Unfortunately the dataflash logging regularly changes as we add new messages or change existing ones to add or change fields, so the documentation gets outdated fast.

Regarding the asked parameters, they are, respectively, throttle input, throttle output and throttle hover. Input and output are the throttle requested to the attitude control and output produced by the motors. The hover is the throttle needed for the vehicle to be hovering.

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Francisco, regarding the dataflash logs, I tried once to use them for geotaging aerial photos; when I wanted to load the log, for that purpose, it would not load it, and it said no FMT messages ( format?) although there was a .bin file in the SD card. Do you know how to solve this problem and ensure that GPS date is logged in the .bin file and how to use it for geotagging?

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You probably had a logging problem, recent (maybe beta) versions will alert you of bad logging.

Thanks a lot. It was not the first time. It keep giving me that “FMT message”

You may need a better SD card. If there are no FMT messages in the log, then it is most likely an empty log as it will have failed writing the first messages.

Hi Francisco,

Quick question but, how is the logging done by ArduPilot? Since the logs are downloaded from the Pixhawk, my first assumption is that pixhawk is responsible with writing these logs and Ardupilot only does the analysis.


That’s unfortunately a common misconception on what ArduPilot and Pixhawk are.

Pixhawk is the hardware, ArduPilot is the software running inside it. Mission Planner is usually the software you run on your PC (although there are others: APM Planner, QGroundControl, MAVProxy, etc.).