Serious bug in the Mavic's "Home Point Me" function - caused loss of drone!

[BuzzyOne]

No offense to the OP, and I am glad DJI is replacing the Mavic as it is the right thing to do, but "complete exoneration" is a stretch. Let's just keep things in perspective as there are things to be learned from this thread about what to do and not do in a situation like the OP had.

Thank you to the OP for being honest here about what happened and putting up with all the right-seat piloting responses.

 

[Chunter]

Something definitely funky with app/mavic homepoint.
Today using my nexus 7 WiFi it said homepoint but on flying the actual hompoint was miles away.tried resetting homepoint whilst flying/landing/flying over and over but homepoint was still the old one.
Landed then used my s6 I stead of the nexus,Tried the same things and home point was all good.
Landed again and tried the nexus again,bizarly it was fine and would update as per normal.
It's as if the mavic also holds the waypoint and needs "rebooting" somehow.
I have no idea how it works and am really confused now.
My s6 basically made my nexus app work again.
Will try and do the same test again next flight.
Typing this on my phone in the middle of nowhere so not the best post ever.
#confused.

 

[scjerry]

Something definitely funky with app/mavic homepoint.
Today using my nexus 7 WiFi it said homepoint but on flying the actual hompoint was miles away.tried resetting homepoint whilst flying/landing/flying over and over but homepoint was still the old one.
Landed then used my s6 I stead of the nexus,Tried the same things and home point was all good.
Landed again and tried the nexus again,bizarly it was fine and would update as per normal.
It's as if the mavic also holds the waypoint and needs "rebooting" somehow.
I have no idea how it works and am really confused now.
My s6 basically made my nexus app work again.
Will try and do the same test again next flight.
Typing this on my phone in the middle of nowhere so not the best post ever.
#confused.

Chunter:
So, here's my list of things to do before posting serious problems here:

1) Identify the date and time of the problem and upload (sync) the log files to the DJI cloud through the DJI Go 4 app. Assuming you are disconnected from the AC but connected to wi-fi, on the lower left of the opening flash page, there is an upward pointing arrow above the "Disconnected" message, or press the three horizontal bars in the upper right and select Flight Record. In the upper right corner of the Flight List, press the small circular icon to obtain a sync menu, then make your choices, assuming the errant flight is recorded. You won't find the words "sync" or "Flight List" in the Mavic Pro User Manual.
2) Use HDSync.com (now AirData) to upload your log to AirData.com. You'll need to establish an account with them.
3) Download the associated Comma Separated Values (.csv) file, and open it with your favorite spreadsheet app. Across the top, peruse the column names. You may need to expand the column widths to see the data. I save these files converting them to .xlsx and discarding the .csv file.
4) Download the .txt file from AirData. I upload it to Phantom Help DJI Flight Log Viewer. Download their .csv and save it to an .xlsx file as before. Mysteriously, you will get a different spreadsheet than from AirData.
5) Deciphering .csv file column headings can be challenging, but here is one document that may help: Mavic Pro .csv Column Descriptions
6) Note that retrieving .dat files using DJI Assistant 2, stopped working with recent firmware upgrades. See DJI Support, Assistant 2 and Flight Data. With recent new releases of both the firmware and Assistant, this will be potentially a future option if/when DJI gets its act together. See How to retrieve a V3 .DAT File
7) See the post by Daroga on the role of the two log files: Dat files and txt files: Log txt vs log dat .
8) For lost drones, the columns most useful are the Home Distance, GPS coordinates of launch HP, and changes in the GPS coordinates of the HP with time. Note that Attempt to reset home point to RC/Mobile device resulted in map, voice and display messages that were reasonable, e.g., recorded home distances that matched the log entry. The Home Point Recorded, a spread sheet line in the log file, in my case, showed a home distance of 12,300 feet, more than 2 miles away, and was NOT reflected in the map, voice and display messages. Home Point Recorded is the location used by RTH. This is evidence of the bug, but I only found it using the Phantomhelp spreadsheet derived from the .txt file.
9) Make sure your mobile device GPS works and agrees with your Mavic. That should be done periodically.
10) Update with the latest Go and firmware. Note that I've rec'd two updates to DJI Go 4 in two or three days. I just installed firmware, v. 01.04.000, then I installed DJI Go 4 v. 4.1.10 two days ago, now, today, they send me DJI Go 4 v. 4.1.11. Improved flight safety, they now claim!
11) Report all of this to DJI using DJI Support - Here for You -> Email.

 

[Chunter]

Not gonna do all that until I can retry and get the same results. Might if been a glitch somehow,if I can recreate it then I will do all if that,the for posting the info though.
The only thing I can think of atm is that my nexus had a fresh goapp install so had no maps available,but that's pure speculation and guesswork.

 

[scjerry]

Not gonna do all that until I can retry and get the same results. Might if been a glitch somehow,if I can recreate it then I will do all if that,the for posting the info though.
The only thing I can think of atm is that my nexus had a fresh goapp install so had no maps available,but that's pure speculation and guesswork.

At least "synch" your flight data, so DJI has it in their cloud. I do that every flight when debugging a problem.

 

[Chunter]

4 flights since my last post 2 last weekend and 2 today.
First 2 flights I'd unrooted my nexus which wiped everything and both flights no problem, drove one kilometre between each flight and all good.
Today first flight fine, drove 4 kilometres and that's where the fun began. Home point recorded with green h next to me on map but on take off it showed homepoint at my last position 4 kilometres away. When I hit rth I had a popup that gave me 2 options , current or last location. Current would land normally and last location it would say too far away and do nothing as it was 4k's away. Once I flew past 200 metres away from myself the distance to homepoint went and was replaced by N/A icon/symbol. All very strange.
At this moment in time I'm thinking it must be the gps in my WiFi nexus not being up to the task. Next few flights will be with my Samsung s6 to see what that does.

 

[scjerry]

RU running the latest firmware v01.04.0000? Some, not all, claim this solves the problem. https://dl.djicdn.com/downloads/mavic/20170919/Mavic_Pro_Release_Notes_en.pdf. I'm skeptical, but will retest when I get mine back from DJI.

 

[Chunter]

Yes mate, all updated.

 

[Gerald Ellis]

This problem has been going on for a while and I thought DJI updated the firmware to solve the problem. Don't know if you have the same problem as others but it's got to the point that you have to monitor where the home point is all the time, just in case.

 

[ZUCSTA]

Amateur hour! Read the manual. Know your equipment. This was not caused by the app nor is it DJI's fault.

Always make sure you get the ; "the home point has been updated. Please check it on the map", before every single take off.

Also check your mobile device GPS is activated if you want use return to home me.

Why didn't you just hit the pause button on your transmitter until you figured out the problem?[emoji848]

So true! Yet many so quick to blame equipment. We all have had screw ups ,most on here share it openly so others can learn. Not to blame DJI Constantly

 

[ZUCSTA]

Chunter:
So, here's my list of things to do before posting serious problems here:

1) Identify the date and time of the problem and upload (sync) the log files to the DJI cloud through the DJI Go 4 app. Assuming you are disconnected from the AC but connected to wi-fi, on the lower left of the opening flash page, there is an upward pointing arrow above the "Disconnected" message, or press the three horizontal bars in the upper right and select Flight Record. In the upper right corner of the Flight List, press the small circular icon to obtain a sync menu, then make your choices, assuming the errant flight is recorded. You won't find the words "sync" or "Flight List" in the Mavic Pro User Manual.
2) Use HDSync.com (now AirData) to upload your log to AirData.com. You'll need to establish an account with them.
3) Download the associated Comma Separated Values (.csv) file, and open it with your favorite spreadsheet app. Across the top, peruse the column names. You may need to expand the column widths to see the data. I save these files converting them to .xlsx and discarding the .csv file.
4) Download the .txt file from AirData. I upload it to Phantom Help DJI Flight Log Viewer. Download their .csv and save it to an .xlsx file as before. Mysteriously, you will get a different spreadsheet than from AirData.
5) Deciphering .csv file column headings can be challenging, but here is one document that may help: Mavic Pro .csv Column Descriptions
6) Note that retrieving .dat files using DJI Assistant 2, stopped working with recent firmware upgrades. See DJI Support, Assistant 2 and Flight Data. With recent new releases of both the firmware and Assistant, this will be potentially a future option if/when DJI gets its act together. See How to retrieve a V3 .DAT File
7) See the post by Daroga on the role of the two log files: Dat files and txt files: Log txt vs log dat .
8) For lost drones, the columns most useful are the Home Distance, GPS coordinates of launch HP, and changes in the GPS coordinates of the HP with time. Note that Attempt to reset home point to RC/Mobile device resulted in map, voice and display messages that were reasonable, e.g., recorded home distances that matched the log entry. The Home Point Recorded, a spread sheet line in the log file, in my case, showed a home distance of 12,300 feet, more than 2 miles away, and was NOT reflected in the map, voice and display messages. Home Point Recorded is the location used by RTH. This is evidence of the bug, but I only found it using the Phantomhelp spreadsheet derived from the .txt file.
9) Make sure your mobile device GPS works and agrees with your Mavic. That should be done periodically.
10) Update with the latest Go and firmware. Note that I've rec'd two updates to DJI Go 4 in two or three days. I just installed firmware, v. 01.04.000, then I installed DJI Go 4 v. 4.1.10 two days ago, now, today, they send me DJI Go 4 v. 4.1.11. Improved flight safety, they now claim!
11) Report all of this to DJI using DJI Support - Here for You -> Email.

Good solid advice !!

 

[scjerry]

Yes mate, all updated.

An Aussie?

 

[Zonian]

Wow...I just read this entire thread. This is my first post in the forum as I have only been a Mavic owner for a few weeks.

The fact that DJI is replacing Finlayson's MP @100% indicates to me that they are admitting a problem.

I am curious as well; has DJI ever confirm that this issue has been fixed?

 

[scjerry]

Wow...I just read this entire thread. This is my first post in the forum as I have only been a Mavic owner for a few weeks.

The fact that DJI is replacing Finlayson's MP @100% indicates to me that they are admitting a problem.

I am curious as well; has DJI ever confirm that this issue has been fixed?

Bud Walker, and perhaps others, have mentioned the 20 meter rule, whereby attempts to change the HP to a location that is less than 20 meters away will result in the aircraft RTHing to the original launch HP, not the requested location. Has anyone found reference to this in the manual? And is it 20 or 30 meters as intimated in the DJI SDK site? I think I've found evidence that if an attempt to change the HP (older firmware) is as far away as 30 feet, it may go home to an HP location established from a previous flight, perhaps days prior.

As to fixing the issue, I'll do some more testing with the latest firmware and let you know.

 

[BudWalker]

Bud Walker, and perhaps others, have mentioned the 20 meter rule, whereby attempts to change the HP to a location that is less than 20 meters away will result in the aircraft RTHing to the original launch HP, not the requested location. Has anyone found reference to this in the manual? And is it 20 or 30 meters as intimated in the DJI SDK site? I think I've found evidence that if an attempt to change the HP (older firmware) is as far away as 30 feet, it may go home to an HP location established from a previous flight, perhaps days prior.

As to fixing the issue, I'll do some more testing with the latest firmware and let you know.

You're mistaken. What I said was that whenever RTH is initiated within 20 meters to the HP the Mavic will descend where it is. Has nothing to do with resetting the HP. It's just a coincidence that you reset the HP. When you initiated RTH it was within 20 meters of the new HP so it just descended where it was.

 

[Chunter]

I'm gonna look at uploading my flight logs as has been posted slowly over the next week,busy week incoming, but at this moment in time I'm swinging towards the problem being my gps unit in my nexus 7. Flew today using my s6 and all was Good,albeit on a smaller screen.
Does anyone have a recommendation for a cellular android tablet that won't break the bank?

 

[scjerry]

You're mistaken. What I said was that whenever RTH is initiated within 20 meters to the HP the Mavic will descend where it is. Has nothing to do with resetting the HP. It's just a coincidence that you reset the HP. When you initiated RTH it was within 20 meters of the new HP so it just descended where it was.

Thanks for the clarification. I guess what I'm after are some DJI docs on the matter. Sorry I misquoted.

 

[msinger]

What I said was that whenever RTH is initiated within 20 meters to the HP the Mavic will descend where it is.

This is true if obstacle avoidance is disabled. If obstacle avoidance is enabled, the Mavic will still return to the home point if RTH is initiated when the Mavic is between 5 - 20 meters from the home point. When less than 5 meters from the home point, it will always auto land at its current location.

 

[scjerry]

This is true if obstacle avoidance is disabled. If obstacle avoidance is enabled, the Mavic will still return to the home point if RTH is initiated when the Mavic is between 5 - 20 meters from the home point. When less than 5 meters from the home point, it will always auto land at its current location.

Let us in on the source, guys! Many of us are novices.

 

[msinger]

Let us in on the source, guys! Many of us are novices.

That information is from the Mavic manual. You can download the manual here.