Newbie Needs Help with Altitude Issue

[VLL]

A 10 ft error/drift seems like a lot to me, but I have no significant experience with any drone other than this one. I tried both the Mavic Mini and Mavic 2 Zoom before settling on the Mavic 2 Pro. I never noticed any altitude discrepancies, but I easily could have missed them. I'm still cultivating my sense of what to be aware of and when.

As for LAANC authorization, I misunderstood how the structure rule worked. Appreciate the advice. I will stay at 50 ft and under in this area. I don't have to go far to find a nice area for flying that has a 200 foot limit, and if I want more than that, there are areas where I can do take it up to 400 that aren't all that far away. I still would like to do a longer and higher flight to see what sar104 might tell me about my IMU. And to see if there is something going on that is causing it to lose calibration. Forecast for the next few days suggests I won't be able to do that until next week. But as soon as I can, I'll do a longer, higher flight in an area authorized for it and post the file.

Thanks everyone. I appreciate the generosity of your insights, guidance, and experience.

 

[Bbarr]

A potential problem with my barometer was not what I was hoping to hear on a drone I’ve had for only two weeks . . . ?.

Seems like the Airdata file may be helpful If anyone with the know how wants to take a look. Here is the flight that told me I was still 80 ft or so above ground as I neared my landing pad:


Then this is the flight that suggested I was - 10 ft in altitude on my second landing a few minutes later.


Not sure if these files are what are needed. If they are, do they suggest it’s time to call DJI?

Not sure I believe the max battery temp was 32 F ?

 

[Keule]

Not sure I believe the max battery temp was 32 F ?

I assume you fly with an Android phone/tablet. All of the battery related data fields are not populated when using an Android device. Hence you see a battery temperature of 32° F (or 0° C) in Airdata.

 

[VLL]

Bbarr, interesting question. I just went back through all my Airdata flights. When I was flying the Mavic Mini (for all of about 10 days), I had a lot of variation in my min to max battery temperature during the flights. I don't have any of that data for the Mavic 2 drones. I was first flying a Mavic 2 Zoom. For all flights with that AC, the Max Bat temp on the general tab is 32.0F. Then, when I check the battery info tab, it says "Temperature - No data was recorded". Same for all flights with the Mavic 2 Pro that I am now flying. None of my flights, and none of the three batteries, have recorded any temperature data.

Keule, just saw your post as well. I fly with the Smart Controller, which is Android. That would explain why the Mavic Mini recorded the info. I was using my iPhone with the RC.

Sounds like the lack of battery temp is normal for my setup. Maybe?

 

[Keule]

Sounds like the lack of battery temp is normal for my setup. Maybe?

Yes. (Just try your iPhone and GO4 with your M2Z and upload the logs to Airdata)

 

[VLL]

I settled on the M2P, not the M2Z, but I'm sure it would be the same. There's a way to use my iPhone and GO4 when I have a SC? I thought I had to have the regular controller to do that.

 

[Keule]

I thought I had to have the regular controller to do that.

Yes, my fault ... of course you need a regular controller to run with your iPhone

 

[VLL]

I was finally able to get in a flight today with more altitude. I think my IMU issue may have recurred. I meant to change my max height to 300 or higher, and instead took off with it at just under 200. So that's as high as I went, which seemed like plenty. It was about a 15 minute flight. Towards the last part of the flight, I brought it down to what looked like maybe 20 ft or so off the ground, and it was reading about 67. There is no way it was at that height.

I landed it by catching it by hand. Realized later it would have been better to bring it all the way to the ground. So the altitude at landing shows on Airdata as being about 53 feet. I am definitely not that tall. I would have made another flight, but as I walked to my car where I had the spare batteries, the first few drops of rain hit me. The weather will be improving in the next few days.

Can any of the gurus who know how to read this data file (maybe sar104) take a look? I don't like having this issue on my still basically brand new M2P, but at least the bird is responsive to the controls and not doing anything unexpected in flight. I like even less not understanding the issue or what I will need to do about it! For whatever help you all can offer, you have my thanks.

 

[VLL]

I didn't realize it, but the file did not attach. I'm getting a message that the file size is too large. Any advice anyone? Maybe I need another flight that is shorter? (This one was about 15 minutes).

 

[sar104]

I didn't realize it, but the file did not attach. I'm getting a message that the file size is too large. Any advice anyone? Maybe I need another flight that is shorter? (This one was about 15 minutes).

Upload it to Dropbox or Google Drive, and then post a link back here.

 

[VLL]

I am learning no end of new things. This *should* be a link to the doc on google drive. First time I've done this. Fingers crossed. Thanks sar104.

20-04-04-01-39-05_FLY067.DAT

drive.google.com

 

[sar104]

I am learning no end of new things. This *should* be a link to the doc on google drive. First time I've done this. Fingers crossed. Thanks sar104.

20-04-04-01-39-05_FLY067.DAT

drive.google.com

Yes - that still doesn't look good. It's the IMU data that are causing the problem:



GPS altitude brings it back to within 1 meter. Raw barometric is off by 4 meters, which is not great, but not too bad. The IMU vertical velocity data are causing the problem though, leading the sensor fusion height solution to be off by up to 15 meters for IMU1.

 

[VLL]

sar104, thank you!

Can you or anyone with experience with DJI offer me advice on how to communicate with them on this? This strikes me as a warranty issue, not something for DJI Care Refresh. I don't know if the best way to start is via a phone call or via a means that would permit me to send them your graphs or my DAT files (like the DJI forum or email to DJI support).

Again, thanks.

 

[sar104]

sar104, thank you!

Can you or anyone with experience with DJI offer me advice on how to communicate with them on this? This strikes me as a warranty issue, not something for DJI Care Refresh. I don't know if the best way to start is via a phone call or via a means that would permit me to send them your graphs or my DAT files (like the DJI forum or email to DJI support).

Again, thanks.

I would start by opening a support ticket saying simply that the height measurement is very unreliable.

 

[VLL]

Ok. Will do. Once again, thanks for the aid and assist.

 

[VLL]

Thought I would close out this post with an update and a final thanks to sar104 for the expert help.

I opened a support ticket with DJI yesterday (Sunday). I got an automated response advising me, in essence, that due to the covid-19 virus, warranty/repair issues were going to take longer than normal to be handled. I waited until the phone lines were open this morning and called to ask more about that. After waiting a LONG time to get through on the phone, the agent told me I could return the drone for a warranty repair, but there was no real way to predict how long it would take. They quarantine the drones when they arrive for a period of time, and they have reduced staff to handle the issue once the quarantine period is over. Because I am still within my 30 day return period on the original purchase, the DJI agent more or less encouraged me to call the retailer for a faster resolution.

Which is what I did. The general customer service dept kicked me over to a group that handles more high tech electronics, which includes drones. The high tech agent that took my call was excellent. I told him I was more than willing to have DJI handle it under warranty, since the seller had already gone above and beyond by letting me return a Mavic 2 Zoom after I decided I would prefer the Pro. So I had already sent one drone back to them. He told me, basically, no problem. If the drone is malfunctioning, he said, I shouldn't hesitate to send it back to them. They need to receive it, examine it, and then they will send me a brand new one as a replacement. All that will take about two weeks, but at least it is a predictable time line.

The downside for me is that I will now need to deal with DJI to get a refund on my DJI Care Refresh. I have had to do that already -- my first purchase was a Mavic Mini, which I decided was too fragile for my needs; then I got the M2 Zoom, which I decided was a great drone but I would prefer the Pro. Getting refunds on the Care Refresh after returning a drone is time consuming, but DJI has followed through so far with each return. I'm a bit self-conscious about a third return, and a third DJI Care Refresh refund. But I feel reasonably confident DJ will be equally solid refunding me the Care Refresh charge after I make this return.

So that's where I am. Sadly, the drone is going back. Happily, with the help of this forum, I figured out the need to return it win time to take advantage of the excellent return/exchange policies of my seller (B&H Photo, for a quick shoutout). That is proving to be easier and more reliable than going through DJI in this unusual pandemic period (no complaints, by the way; I'm glad DJI is taking good care of their staff).

So to wrap up, thank you all for your input, and a special thanks to sar104 for lending me the expert insights into my flight data. I'm disappointed to have had such a critical problem in a new drone, but thanks to this forum, I got it figured out. Now I will wait for the replacement and hope the next one is in fine shape. If so, then, all's well that ends well. Plus, of course, we all get by with a little help from our friends.

Thanks.

 

[GadgetGuy]

Thought I would close out this post with an update and a final thanks to sar104 for the expert help.

I opened a support ticket with DJI yesterday (Sunday). I got an automated response advising me, in essence, that due to the covid-19 virus, warranty/repair issues were going to take longer than normal to be handled. I waited until the phone lines were open this morning and called to ask more about that. After waiting a LONG time to get through on the phone, the agent told me I could return the drone for a warranty repair, but there was no real way to predict how long it would take. They quarantine the drones when they arrive for a period of time, and they have reduced staff to handle the issue once the quarantine period is over. Because I am still within my 30 day return period on the original purchase, the DJI agent more or less encouraged me to call the retailer for a faster resolution.

Which is what I did. The general customer service dept kicked me over to a group that handles more high tech electronics, which includes drones. The high tech agent that took my call was excellent. I told him I was more than willing to have DJI handle it under warranty, since the seller had already gone above and beyond by letting me return a Mavic 2 Zoom after I decided I would prefer the Pro. So I had already sent one drone back to them. He told me, basically, no problem. If the drone is malfunctioning, he said, I shouldn't hesitate to send it back to them. They need to receive it, examine it, and then they will send me a brand new one as a replacement. All that will take about two weeks, but at least it is a predictable time line.

The downside for me is that I will now need to deal with DJI to get a refund on my DJI Care Refresh. I have had to do that already -- my first purchase was a Mavic Mini, which I decided was too fragile for my needs; then I got the M2 Zoom, which I decided was a great drone but I would prefer the Pro. Getting refunds on the Care Refresh after returning a drone is time consuming, but DJI has followed through so far with each return. I'm a bit self-conscious about a third return, and a third DJI Care Refresh refund. But I feel reasonably confident DJ will be equally solid refunding me the Care Refresh charge after I make this return.

So that's where I am. Sadly, the drone is going back. Happily, with the help of this forum, I figured out the need to return it win time to take advantage of the excellent return/exchange policies of my seller (B&H Photo, for a quick shoutout). That is proving to be easier and more reliable than going through DJI in this unusual pandemic period (no complaints, by the way; I'm glad DJI is taking good care of their staff).

So to wrap up, thank you all for your input, and a special thanks to sar104 for lending me the expert insights into my flight data. I'm disappointed to have had such a critical problem in a new drone, but thanks to this forum, I got it figured out. Now I will wait for the replacement and hope the next one is in fine shape. If so, then, all's well that ends well. Plus, of course, we all get by with a little help from our friends.

Thanks.

On the whole, B&H has been pretty good on defective drone replacements for me, too. I went through three new P4P's with them, to finally get a good one, when they first came out.