Phantom 4 Pro compass problems

Questions & Answers
1

I may have done a stupid thing. I bought a used Phantom 4 Pro, supposedly working perfectly and I seem to have bought a lemon.
All seems fine on the ground but when the thing gets in the air it seems to have a a mind of its own. I get multiple compass errors, speed errors, yaw errors and it’s near impossible to control.

Ive copied a few below

||Flight time|Altitude|Home Dist|Type|Notification|
||00m 00s|0.0 ft|0 ft|Mode|Mode changed to Motors_Started|
||00m 00s|0.0 ft|0 ft|Tip|Log filename: FLY107.DAT|
||00m 01s|0.0 ft|0 ft|Mode|Mode changed to Assisted_Takeoff|
||00m 04s|0.0 ft|0 ft|Mode|Mode changed to P-GPS|
|A|00m 47s|26.2 ft|0 ft|Mode|Mode changed to P-GPS|
|B|01m 11s|26.9 ft|1 ft|Warning|Compass Error (repeated 49 times)|
|C|01m 16s|27.2 ft|4 ft|Warning|Compass Error (repeated 14 times)|
|D|01m 18s|27.9 ft|13 ft|Warning|Speed Error (repeated 4 times)|
|E|01m 18s|33.8 ft|21 ft|Warning|Compass Error (repeated 2 times)|
|F|01m 19s|39.4 ft|26 ft|Warning|Speed Error (repeated 10 times)|
|G|01m 20s|47.2 ft|48 ft|Warning|Compass Error (repeated 8 times)|
|H|01m 21s|61.0 ft|67 ft|Mode|Mode changed to Atti|
|I|01m 21s|61.0 ft|67 ft|Warning|Compass Error (repeated 18 times)|
|J|01m 23s|90.2 ft|109 ft|Mode|Mode changed to P-GPS|
|K|01m 23s|90.2 ft|109 ft|Warning|Compass Error (repeated 9 times)|
||01m 24s|103.0 ft|119 ft||92% Battery at maximum distance|
|L|01m 24s|104.3 ft|119 ft|Warning|Compass Error (repeated 49 times)|
|M|01m 29s|129.3 ft|84 ft|Warning|Compass Error (repeated 7 times)|
|N|01m 30s|128.9 ft|87 ft|Mode|Mode changed to Atti|
|O|01m 30s|128.9 ft|87 ft|Warning|Compass Error (repeated 10 times)|
|P|01m 31s|140.7 ft|89 ft|Warning|Compass Error. Compass Error (repeated 41 times)|
|Q|01m 35s|180.1 ft|95 ft|Warning|Compass Error (repeated 5 times)|
|R|01m 35s|176.5 ft|96 ft|Warning|Yaw Error (repeated 49 times)|
|S|01m 40s|173.6 ft|106 ft|Warning|Yaw Error (repeated 6 times)|
||01m 41s|173.6 ft|106 ft||90% Battery|
|T|01m 41s|173.6 ft|107 ft|Warning|Yaw Error (repeated 18 times)|

Sorry about the poor formatting. I’ve aligned the IMU, I’d calibrate the compass if I could find the option.
Having resisted the temptation to take a very large hammer to it I’m open to suggestions. No chance of getting my money back on it and I’m reluctant to put good money after bad by sending it to DJI.
Any suggestions folks? Or is anyone interested in buying a faulty Obsidian Phantom 4 Pro with a ton of extras :grinning:

2

Have you uploaded your flight logs to air data if you have would you mind sending me the link and I would be more than happy to help try and fix this problem for you, and obviously discuss the issues that you are having in more detail.

3

That would be great, got to walk the dog but will send the link in an hour or so
Thanks!

4

Okay that’s fine however I myself won’t be able to look at it straight away as I am currently away on holiday anyway however I will respond to you ASAP and we can try and get it resolved!

5

Try the following, then do another IMU calibration and see if the results are any better

6

The weird thing is that option to calibrate the compass does not appear on my app ???

7

Found this on a “how to calibrate” site

Hope it may help… Colin

8

Yes thanks, I now now where to look :grinning:

9

Let us know if that cures things @pete.mcarthur ?

10

I’ll keep you up to date but the weather is looking a bit dodgy for the next few days. As you as I can get a window I’ll give it a go

11

Well I am both very happy and feel very stupid at the same time! The main problem seems to have been the compass calibration and once I found out how to do it, we’re looking good.

I cannot believed that I overlooked this, I know I’m an idiot. Many thanks for all the suggestions and especially to @alexmciver who helped me via PMs

Really glad I didn’t take the hammer to it :grinning:

12

Glad to be of help :wink:

13

Your welcome.

14

You are more than welcome and I have now checked your flight logs and all seems to be in working order however I do recommend that from now on you do a Manual takeoff rather than an assisted auto takeoff because if something happens during takeoff you can stop it quicker than you can if the motors were in auto

15

Will do,
Thanks again!

16

You are very welcome I’m glad that I was able to help you get it resolved so that you didn’t have to put a hammer to it and now maybe you should add it to your list of drones in this forum?

17

I’ve only ever used auto takeoff once (to check if precision landing works) but I’m curious how you come to the above

18

The reason why I said that is because I was told that sometimes people have done autoland and take off and it doesn’t give enough power to the motors and sometimes drones have tipped over

19

Ok , never heard that one.

The original issue here was a simple compass calibration was needed, this was causing the yaw issues.

20

Yes it would have been and it now looks as though after checking Pete’s logs everything is running as should