Mavic Flight Log Retrieval and Analysis Guide

[msinger]

There may be a way for CsvView to determine platform type and then choose a TXTlogToCSVtool that has a better chance of working properly.

FYI, I just updated my online log viewer to work like this.

 

[sar104]

FYI, I just updated my online log viewer to work like this.

Nice work.

 

[Ron (MM)]

 

[dRaGoNfLyLoUgHeEd]

Okay thank you.

 

[droneofarc]

Awesome work to help those that are struggling to understand. To bad that people have to learn the hardware before getting the information that would help them.

 

[GadgetGuy]

Awesome work to help those that are struggling to understand. To bad that people have to learn the hardware before getting the information that would help them.

If they learned the limitations of the hardware, they wouldn't have to learn the hard way!

 

[BadWolf1]

With the introduction of the Mavic Mini ...
If you are not interested in long-winded details ....

1. OSD.latitude, OSD.longitude – the sensor fusion solution for position (not the raw GNSS position data, which is only in the DAT file);

Comments welcomed...

Deep breath, my first post here. Hello.
I'm new to drones having owned the Mavic Mini for all of a week. I'm also a bit of stats and numbers geek so was very interested in the telemetry and what I can get out. Lots of thanks to the people who have already trodden this path and share the "long-winded details".
It seems the DAT file I can download from the Mini using DJI assistant contains a bunch of sub files but having extracted them they don't seem to be readable. There is a single DAT file on the phone which IS readable, but there are more flights and richer data in the .TXT files so I can move them from phone to computer and convert to CSV, do a bit of pre-processing with a script and load into Excel.

Some of the fields are hard to make sense of. "Battery safe fly radius" you'd expect to go down with the battery, but it does not. (22,000 on a full battery would impressive, but I saw it on 15% ) Battery temp says it is in degrees C, but the figure in 70-80 range would be to hot to hold if that were true. "Calc" fields are plainly calculated but often what's calculated and/or how it differs from a similar quantity elsewhere is hard to know, and details have proved hard to find. Many fields are blank, at least for the Mini. Despite this I have plenty of useful data. My script strips out columns which aren't helpful (to me) and applies excel formatting (you can format a cell with different way of showing 0, including 'not at all' which is a good way to only see cells with values) and custom formatting (make some values red or green), scales a few things to percentages... Out of curiosity I ran the log files from the thread at
DJI Not Honouring Warranty - Claims it was user error
through my script and part of the result is below. Impact happens shortly afterwards, and has been covered on the original thread. I've stripped the whole degrees from the lat/lon so it doesn't contain the location info if the pilot removes his original upload, but it doesn't change the calculations.



So: line 9 has a double GPS warning, 1.3 Seconds later there is another. The Pitch Roll and Yaw say the Drone is reasonably stable in the the air, and there are no control inputs until the end. XSpeed, YSpeed and ZSpeed I think come from the IMU, and they say the done moves just enough to register
Column D is distance of the current lat/lon from the previous one, E is D divided by the difference in time stamps, (speed). And F is change of speed divided by change of time (acceleration/braking)
The lat/lon says the drone pulled some dramatic acceleration and braking but everything else says not.

Granted this is (a) a noob reading (b) one set of data for one model but my reading of this is the weak GPS message and the erratic movement in the lat /lon trace are signs of the same thing meaning lat/lon comes from GNSS not be the sensor calculation - at least on some models.
I think from reading what the pilot said, reviewing the flight on the phone may show the logged lat/lon values giving the impression that the drone jumped about when only the satellite calculations were shifting.

Boy, that was long for a "Thanks, and I saw this" post. But thanks again, I couldn't have done any of this without the start you gave

 

[slup]

Deep breath, my first post here. Hello.
I'm new to drones having owned the Mavic Mini for all of a week. I'm also a bit of stats and numbers geek so was very interested in the telemetry and what I can get out. Lots of thanks to the people who have already trodden this path and share the "long-winded details".
It seems the DAT file I can download from the Mini using DJI assistant contains a bunch of sub files but having extracted them they don't seem to be readable. There is a single DAT file on the phone which IS readable, but there are more flights and richer data in the .TXT files so I can move them from phone to computer and convert to CSV, do a bit of pre-processing with a script and load into Excel.

Some of the fields are hard to make sense of. "Battery safe fly radius" you'd expect to go down with the battery, but it does not. (22,000 on a full battery would impressive, but I saw it on 15% ) Battery temp says it is in degrees C, but the figure in 70-80 range would be to hot to hold if that were true. "Calc" fields are plainly calculated but often what's calculated and/or how it differs from a similar quantity elsewhere is hard to know, and details have proved hard to find. Many fields are blank, at least for the Mini. Despite this I have plenty of useful data. My script strips out columns which aren't helpful (to me) and applies excel formatting (you can format a cell with different way of showing 0, including 'not at all' which is a good way to only see cells with values) and custom formatting (make some values red or green), scales a few things to percentages... Out of curiosity I ran the log files from the thread at
DJI Not Honouring Warranty - Claims it was user error
through my script and part of the result is below. Impact happens shortly afterwards, and has been covered on the original thread. I've stripped the whole degrees from the lat/lon so it doesn't contain the location info if the pilot removes his original upload, but it doesn't change the calculations.

View attachment 101118

So: line 9 has a double GPS warning, 1.3 Seconds later there is another. The Pitch Roll and Yaw say the Drone is reasonably stable in the the air, and there are no control inputs until the end. XSpeed, YSpeed and ZSpeed I think come from the IMU, and they say the done moves just enough to register
Column D is distance of the current lat/lon from the previous one, E is D divided by the difference in time stamps, (speed). And F is change of speed divided by change of time (acceleration/braking)
The lat/lon says the drone pulled some dramatic acceleration and braking but everything else says not.

Granted this is (a) a noob reading (b) one set of data for one model but my reading of this is the weak GPS message and the erratic movement in the lat /lon trace are signs of the same thing meaning lat/lon comes from GNSS not be the sensor calculation - at least on some models.
I think from reading what the pilot said, reviewing the flight on the phone may show the logged lat/lon values giving the impression that the drone jumped about when only the satellite calculations were shifting.

Boy, that was long for a "Thanks, and I saw this" post. But thanks again, I couldn't have done any of this without the start you gave

Hi there & welcome to the forum ?

For the newest DJI aircraft's the onboard DAT log is encrypted, not readable by others then DJI ... but the mobile device DAT log (containing raw sensor & motor data) & the mobile device TXT log (Telemetries ... roughly said) is readable.

If you are a number geek I imagine that graphs is within the field of your interest ... graphs is a much quicker way to get an overlook out then rows & columns filled with figures. I recommend you to try CsvView out (download it here ---> CsvView Downloads ... and give our forum member @BudWalker a social distant hug for making it & provide it for free ) , CsvView can open TXT & DAT logs directly without any conversions.

Read then through post 1 in this thread (cred goes to @sar104 for that) ... in section 5 there you find explanations to some of the signals available in the logs ... then it's up to you to try out other signals & follow "crash threads" here at the forum to gain more knowledge about other signals, how to interpret them & which to chose to look at in different situations.

Below how a fully opened TXT log could look in CsvView ... the graph window with freely chosen signals, the event log window & the sat view with the flight path, all is locked together ... moving the cursor in the graph window update the 2 other.

 

[BadWolf1]

Hi there & welcome to the forum ?


If you are a number geek I imagine that graphs is within the field of your interest ... graphs is a much quicker way to get an overlook out then rows & columns filled with figures. I recommend you to try CsvView out (download it here ---> CsvView Downloads ... and give our forum member @BudWalker a social distant hug for making it & provide it for free ) , CsvView can open TXT & DAT logs directly without any conversions.

Read then through post 1 in this thread (cred goes to @sar104 for that) ....

Hi , and thanks for the welcome. I needed to fix some Java issues to get csvView going. And yes serious thanks due to @BudWalker . The trouble as newbie is there is so much data, CSVView lets me chart things I don't understand yet The spreadsheet lets me see how some of the things are calculated. Excel can have only 2 Y Axis scales but CSVView can have as many as I want.

The items in the first post (and yes great work there - thanks @sar104 ) make immediate sense. Others arouse curiosity but don't make sense (like SafeFlyRadius). I can see I have plenty of learning in front of me

 

[dap455]

Thank you Sar104, excellent very detailed explanation.

 

[Slade]

A great Christmas gift. Definitely a Saved post. Thanks???

 

[Laborous]

Is there an easy way of printing the “Flight log retrieval and analysis guide”?

 

[sar104]

Is there an easy way of printing the “Flight log retrieval and analysis guide”?

I can post a PDF version of the file if that would help.

 

[ghost.its]

Thanks a lot for your time and effort. This is great.

 

[El Principio]

Just a tiny bonus for newer Android phones...

Settings >> Device Care >> Storage >> Advanced >> Files >> DJI >> dji.go.v5 >> Flight Record gets you to the .txt on the phone.

You can use the share icon from there to email it to yourself or whomever

 

[lyapounov]

Hello
thank you for the superb work !! Much appreciated

I am writing a piece of javascript to decode my txt files, based on Dji Log Parser
This library is quite old, but on my mavic Air 2 txt files, I have most information.

One main info which is not trapped is APP_TIP and APP_WARN

It works fine on some other txt files which I found on some other libraries, with phantom mavic and spark file. But on my mavic air 2, I don't trap those events, while the two websites I have tested (airdata and phantom viewer) can trap those events.

Is it that the format has changed on the mavic air 2 ?

Thx !

 

[Camino Ken]

I can post a PDF version of the file if that would help.

Let me know when the PDF is available.

 

[Goldiedpimp]

Hello! I'm Having issues trying up troubleshoot the error I'm getting.

I've been getting motor current, check props error. I pulled the logs but I'm not sure if I'm doing it correctly, but when I load the dat file in assistant, it doesn't show anything.

I loaded it in csview,but did not see anything that looked out of place. I changed the props and updated firmware, but it happened again today. It feels like the front right motor MIGHT be a little hotter than the others, but not by much.

Tomorrow I'll try taking the temps of the motors and see if there's a measurable difference.

Here is a link to the actual file.
Dat

 

[boblui]

Hello! I'm Having issues trying up troubleshoot the error I'm getting.

I've been getting motor current, check props error. I pulled the logs but I'm not sure if I'm doing it correctly, but when I load the dat file in assistant, it doesn't show anything.

I loaded it in csview,but did not see anything that looked out of place. I changed the props and updated firmware, but it happened again today. It feels like the front right motor MIGHT be a little hotter than the others, but not by much.

Tomorrow I'll try taking the temps of the motors and see if there's a measurable difference.

Here is a link to the actual file.
Dat

Cant see anything wrong. Unfortunately the motor current data is not very reliable for Mini. The current for the Left-front motor is always a lot higher.

 

[Goldiedpimp]

Cant see anything wrong. Unfortunately the motor current data is not very reliable for Mini. The current for the Left-front motor is always a lot higher.

I guess i should have specified that it's a mavic pro platinum.

I didn't see anything that looked abnormal either.

Thanks for looking!