Weird new Mavic Pro gimbal spasm

WarezMonkey · May 31, 2019

Hi. I just got my mavic pro replacement back from DJI. I crashed my original one and then sent it in for care refresh and they replaced it with a new one.
I've had this new one out a few times and twice it has done this scary weird thing that I can't make sense of.

EDIT: hey, doing some more reading... might this be related to my SD card? I read somewhere that there was an issue with some SD cards at the start or end of recording. The videos I posted both have an issue 1-2s into the recording.

I will try and use the forum format suggested.

Problem? gimbal or mavic suddenly looks to the sky and freaks out without any RC inputs (which freaks me out). The first time was with me pushing the stick forward in flight, the 2nd time it was in Active Track mode. The gimbal seems like it looks to the sky but the logs indicate no change in pitch,
Was unit in a crash? no
What have you tried so far?: calibrated RC. Reviewed flight logs
What device are you using? iPhone XS
What firmware are you running ( aircraft, remote controller)? newest
What Go app version are you using? newest version
Any modification? its all a stock unit
Did you change anything or install any apps? No
Do you have a video or pictures of the problem? Yes, here is a youtube link:
The flight record is attached. The video starts at T=31:46.1 and the freakout is about 1 minute in.

I also have a short video of this happening last weekend when I flew it.

Mossiback · May 31, 2019

This does not look like the the classic gimbal reset that some have had, but you can read more here: Search results for query: gimbal freakout

You state you have the newest firmware/software. If it were me I would open a case with DJI and return it for another "new" Mavic.

WarezMonkey · May 31, 2019

It does seem like a form of freakout. I definitely freaked out when it happened.

Thanks for the link. Reading some of those I think I should get a Sandisk Extreme and not just the Ultra that I have.

Mossiback · May 31, 2019

The Ultra is not fast enough, especially for 4K video. You want to see a U3 rating.

runeOfRune · May 31, 2019

After you exit tracking, RC is registering gimbal wheel input downwards, but no reaction from gimbal. Then it registers gimbal downwards input before the gimbal goes up. What's with the input starting at 112s? Was that your input? I wonder what IMU was thinking, can you upload the .DAT from M1P?

WarezMonkey · May 31, 2019

runeOfRune said:
After you exit tracking, RC is registering gimbal wheel input downwards, but no reaction from gimbal. Then it registers gimbal downwards input before the gimbal goes up. What's with the input starting at 112s? Was that your input? I wonder what IMU was thinking, can you upload the .DAT from M1P?

Wow! What app is that? That is awesome. Thank you for looking at the log.
After the freakout i shut off the auto-track and tried to angle the gimbal down but it was not responding. That further continued my freakout as I was over the river. It seems like when this happened I was unable to command it and I also tried moving the mavic closer so it wasn't over the river.

I will grab the dat file and try and share it soon. Hope I do it right.

runeOfRune · May 31, 2019

CsvView Introduction

Judging by your description, looks like the spasm didn't register in the .txt, maybe we can find something in the .DAT event stream.

WarezMonkey · May 31, 2019

The DAT file was large. Hopefully this is what you meant. I connected it to the DJI assistant 2.

Dropbox

www.dropbox.com

runeOfRune · May 31, 2019

106.603 : 6414 [L-GIMBAL]The 1st gimbal 0 disconnect

Try formatting the SD card or swapping for another one. If the issue persists, open a case with DJI, tell them to look at FLY002 106s in.

Are you using the same SD card in both drones?

WarezMonkey · May 31, 2019

Oh man. I see that now in the csv.
This was the same SD card I used without issue in my previous drone that I crashed. I ordered an Extreme that will arrive tomorrow and I will play in a safe area to try and re-create the issue. At the same time I'll open a case.
Thanks for all your help.

brett8883 · Jun 1, 2019

WarezMonkey said:
Hi. I just got my mavic pro replacement back from DJI. I crashed my original one and then sent it in for care refresh and they replaced it with a new one.
I've had this new one out a few times and twice it has done this scary weird thing that I can't make sense of.

EDIT: hey, doing some more reading... might this be related to my SD card? I read somewhere that there was an issue with some SD cards at the start or end of recording. The videos I posted both have an issue 1-2s into the recording.

I will try and use the forum format suggested.

Problem? gimbal or mavic suddenly looks to the sky and freaks out without any RC inputs (which freaks me out). The first time was with me pushing the stick forward in flight, the 2nd time it was in Active Track mode. The gimbal seems like it looks to the sky but the logs indicate no change in pitch,
Was unit in a crash? no
What have you tried so far?: calibrated RC. Reviewed flight logs
What device are you using? iPhone XS
What firmware are you running ( aircraft, remote controller)? newest
What Go app version are you using? newest version
Any modification? its all a stock unit
Did you change anything or install any apps? No
Do you have a video or pictures of the problem? Yes, here is a youtube link:

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

The flight record is attached. The video starts at T=31:46.1 and the freakout is about 1 minute in.

I also have a short video of this happening last weekend when I flew it.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Your SD card is shot or the wrong kind I’ll bet a nickel you are using either a card that says C10 it it’s a SanDisk Extreme Plus 64 GB

WarezMonkey · Jun 1, 2019

It was a SanDisk Ultra 64 GB that says C10
I now have a SanDisk Extreme128GB that says V30. I flew it last night for a good 45 minutes with no freak out.

brett8883 · Jun 1, 2019

WarezMonkey said:
It was a SanDisk Ultra 64 GB that says C10
I now have a SanDisk Extreme128GB that says V30. I flew it last night for a good 45 minutes with no freak out.

You owe me a nickel ?.

coliwabl · Jun 2, 2019

I've had this issue occur many times. It is really scary midflight but on each occasion, the gimble regained it's composure and I was able to have it get back home. I still am not sure of the exact problem but I know that after it does this, I reset the IMU and calibrate the gimble and of course calibrate the drone and the problem is no more. I now re-calibrate the IMU about every three flights. There is no harm by doing so, so why not be safe. I've now had my platinum for a year with over 50 flight hours.

brett8883 · Jun 2, 2019

coliwabl said:
I've had this issue occur many times. It is really scary midflight but on each occasion, the gimble regained it's composure and I was able to have it get back home. I still am not sure of the exact problem but I know that after it does this, I reset the IMU and calibrate the gimble and of course calibrate the drone and the problem is no more. I now re-calibrate the IMU about every three flights. There is no harm by doing so, so why not be safe. I've now had my platinum for a year with over 50 flight hours.

It has something to do with the SD card being used. Don’t ask me why the SD card causes a physical problem with the gimbal though I have an idea.

What I speculate is happening is that, crude explanation to follow, how it’s suppose to work is there is a buffer between what the camera records and what is written to the SD card so that the information from the camera isn’t lost. The buffer takes the slack when the SD card is unable to keep up with the camera. However, if your SD card is too slow then the buffer will fill up and then there is an back up of information that can’t go anywhere. This causes the software in camera to crash and it automatically resets itself to clear the buffer.

So basically your SDs minimum write speed is not up to task. Which one are you using? Again I’ll bet a nickel it either says C10 or it’s the Sandisk Extreme Plus 64 GB (a card which I find does not match the U3 description it’s labeled with) note: this is specifically the 64 GB version and the other sizes of the Sandisk Extreme Plus don’t have this issue.

runeOfRune · Jun 2, 2019

It's kind of lame from the DJI side that the enitre gimbal software crashes. I'm not entirely convinced it's related to the card but hey, who knows.

WarezMonkey · Jun 3, 2019

Thanks everyone for all the advice. I flew a lot yesterday with my new SanDisk Extreme 128GB recording off and on at 4k resolution and no gimbal freak outs. I'll keep an eye for the issue and report if it happens again, but I think this one is good for now.

I think the scary part was that I was using active track. When the gimbal freaked out and reset, Active track "lost the subject" and so the drone stops hard mid-flight which makes it look like it's not just the camera and my drone is about to fly away.

I owe Brett a nickel.

brett8883 · Jun 3, 2019

WarezMonkey said:
Thanks everyone for all the advice. I flew a lot yesterday with my new SanDisk Extreme 128GB recording off and on at 4k resolution and no gimbal freak outs. I'll keep an eye for the issue and report if it happens again, but I think this one is good for now.

I think the scary part was that I was using active track. When the gimbal freaked out and reset, Active track "lost the subject" and so the drone stops hard mid-flight which makes it look like it's not just the camera and my drone is about to fly away.

I owe Brett a nickel.

Just for anybody reading this in the future I have been tracking this issue for awhile and I have enough data at this point to make some conclusions.

This issue is due to a SD cards insufficient minimum write speed. I’m not 100% sure why this causes the gimbal to freak out but I know this is the cause.

The minimum write speed in a genuine SD card(not fakes) is represented by symbols the card. For the Mavic you need a card that says U3 or V30. These are two different systems but say the exact same thing.

I have also enough evidence to conclude the Sandisk Extreme Plus SPECIFICALLY the 64 GB version does not have the advertised minimum write speed even though it is advertised as a U3 V30 card. STAY AWAY from the Sandisk Extreme Plus 64 GB.

The other sizes of Sandisk Extreme Plus are perfectly fine. I in-fact use a Sandisk Extreme Plus 32 GB and it works great.

This issue is specific to the Mavic Pro and have not collected any evidence that it occurs in other drones though other issues can be expected if using an under preforming SD card