Help with log analysis

I’ve attached flash log file of a flight that ended with me flicking from RTL to Stabilize causing the copter to descend rapidly and crash. I’m having issues reading the flash log but the .tlog from the same flight show channel 3 (throttle) going from full to zero to full to zero at the end of the log. Last thing I remember is pushing the throttle up before switching the mode from AltHold (which went to RTL when hitting the Geofence) to Stabilize.

Can someone confirm for me that the flash logs shows what I described? Any other info on what brought the copter down so quickly would be most appreciated as well. If you have time to explain what you looked at in the logs I’m trying to improve my log reading skills/knowledge so it would be helpful to hear what you looked at in the logs.

Cheers.

[quote=“dazzab”]I’ve attached flash log file of a flight that ended with me flicking from RTL to Stabilize causing the copter to descend rapidly and crash. I’m having issues reading the flash log but the .tlog from the same flight show channel 3 (throttle) going from full to zero to full to zero at the end of the log. Last thing I remember is pushing the throttle up before switching the mode from AltHold (which went to RTL when hitting the Geofence) to Stabilize.

Can someone confirm for me that the flash logs shows what I described? Any other info on what brought the copter down so quickly would be most appreciated as well. If you have time to explain what you looked at in the logs I’m trying to improve my log reading skills/knowledge so it would be helpful to hear what you looked at in the logs.

Cheers.[/quote]

I’ll start looking at this. Please include the tlog?

[quote=“jschall”]
I’ll start looking at this. Please include the tlog?[/quote]
Thanks. I’ve attached the flog. Hope I got the right one.

Your telemetry log is from a different day and is not from a flight.

Your dataflash log is corrupted. Two lines are corrupted (16905 and 16969) and there’s a large number of messages which are out-of-order (for example, the jump at 7948 and 7949). Are you downloading logs over 3dr radio?

If the log is still on the PX4, please try reading it over USB or directly off the SD card and see if it helps.

Thanks.

Alright, after some discussion with tridge:

It would be appreciated if you could get back to me with:

  • What method did you use to download the log?
  • Is the log still on the Pixhawk?
  • If so, can you send some new copies: one read over USB and one directly from the SD card?

Using MAVLink rather than CLI to download logs is best: groups.google.com/forum/#!msg/d … vFgpXViEkJ

[quote=“jschall”]Your telemetry log is from a different day and is not from a flight.

Your dataflash log is corrupted. Two lines are corrupted (16905 and 16969) and there’s a large number of messages which are out-of-order (for example, the jump at 7948 and 7949). Are you downloading logs over 3dr radio?

If the log is still on the PX4, please try reading it over USB or directly off the SD card and see if it helps.

Thanks.[/quote]

I downloaded the flash log using USB. I appreciate your help but I don’t think it’s worth spending time on this as I’ve done a lot of flying since then.

Cheers.

jschall: regarding corruption of data: please see github.com/diydrones/ardupilot/issues/825