Fixing DJI's Compass Problem
- Thread starter ianwood
- Start date
ianwood said:
Just today it happened to me. I'm assuming it caused my flyaway. First flyaway in the four months I've had it. RTH function worked though but you can see in the video it had problems even after it went into RTH mode. I'll post video in a few minutes!
Also, went through the Calibration 3 times after it kept telling me that there was a compass problem.
Elginet said:
I don't want to dismiss your experience but if you are flying in Illinois, you should not be effected by magnetic declination as you are right where the declination is the least along the agonic line. You may want to look closely for a compass related issue such as taking off in an area with hidden metal objects, or having a partially magnetized compass, but I don't think this thread is related to your issue. Post your video to a separate thread and we can see for sure.
flight-of-eye said:
I haven't considered this and it could be related but given we all have the GPS in the stock location, it would have to be a bug in either the Phantom Assistant or the firmware. And I don't see how it would only be limited to those of us in areas of high magnetic declination. I did think the video was going to be about rotating the compass which is a common misconception that it fixes the declination issue which it really doesn't.
ianwood said:
Being that it is at approximately 3cm above center that may be enough to create the TBE, not sure on the other flight abnormalities, but if this is out it may have an affect on flight navigation.
I don't want to dismiss your experience but if you are flying in Illinois, you should not be effected by magnetic declination as you are right where the declination is the least along the agonic line. You may want to look closely for a compass related issue such as taking off in an area with hidden metal objects, or having a partially magnetized compass, but I don't think this thread is related to your issue. Post your video to a separate thread and we can see for sure.
Here's the video of what happened today. https://vimeo.com/89670891
Here's the video of what happened today. https://vimeo.com/89670891
Where did you calibrate your compass? If you did it in that parking lot there might be some metal in the pavement distorting the calibration.Elginet said:
It's a forest preserve parking lot. I've flown there about 10 times and never had issue like this until today.
Elginet said:
You're definitely having compass related issues. But your mistake is calibrating your compass on a paved or concrete area. You don't know what pipes, conduit, rebar, etc. is under there. That the Phantom took three times to calibrate should tell you there is a problem. As soon as you take off, the magnetic field changes and soon your Phantom is doing exactly what just happened in that video.
Check the compass mod value in Phantom Assistant. If it's OK, go out a good 50ft into the field, put everything in your pockets 10ft away from the Phantom along with the TX, re-calibrate your compass and you won't have any problem.
Hi
I have this issue too. I am in Grahamstown, South Africa which has a declination of -27.8. I experience it the way you have described and also the toilet bowl effect. I do a compass dance before every flight. It often takes 6 or 7 attempts at compass calibration before it is happy. Even then, sometimes it is up in the air for a couple of minutes and it indicates compass issues. I have done the software advanced calibration multiple times even though my compass is sitting in the ballpark of acceptable. The Phantom 2 wanders around and I have to constantly correct with the sticks. Sometimes it is better than others but it is never 100% stable. If I send it out and then bring it back it always veers off to one side. Sometimes I set off and it starts circling so badly that it lands by tumbling across the ground. I use it with a GPS tracker attached because I fear that I will lose it if it starts misbehaving in the air.
Hope this makes sense
Harold
I have this issue too. I am in Grahamstown, South Africa which has a declination of -27.8. I experience it the way you have described and also the toilet bowl effect. I do a compass dance before every flight. It often takes 6 or 7 attempts at compass calibration before it is happy. Even then, sometimes it is up in the air for a couple of minutes and it indicates compass issues. I have done the software advanced calibration multiple times even though my compass is sitting in the ballpark of acceptable. The Phantom 2 wanders around and I have to constantly correct with the sticks. Sometimes it is better than others but it is never 100% stable. If I send it out and then bring it back it always veers off to one side. Sometimes I set off and it starts circling so badly that it lands by tumbling across the ground. I use it with a GPS tracker attached because I fear that I will lose it if it starts misbehaving in the air.
Hope this makes sense
Harold
ianwood said:
That was an interesting event he had. I am very surprised that after losing control that turning off the TX and triggering RTH saved it. RTH needs everything to be functioning normally in order to return and land. Very strange indeed.
Regarding compass calibration. I calibrate the compass the first flight of every session. I fly all the time off of my back patio, over a green belt behind my house. My patio has a rebar grid in it and I calibrate with the model held at shoulder level. Both my P2V and P2Z have never failed a calibration nor exhibited any compass related behavior. I bring this up as a data point. I never empty my pockets, always have a phone on my hip.
Harold1966 said:
You win the declination contest followed closely by Paw in Greenland and 3 others from Christchurch, NZ.
Paw, what have you changed on the P2V and do you get the same symptoms? I am assuming yes, but want to confirm.
I live in Southern California and have had my PV2 for 2 months. Have not had any problem with drift or fly aways - yet.
I just flew my third PV2 today. It is demonstrating the same problems, toilet bowling, hard to get compass to calibrate, and fly away. Something else I noticed is that while hovering overhead with gps operational I pushed it off its hover point and it immediately lost gps lock and the lights started blinking yellow and it went into its fly away routine. Are you going to get anything done with DJI? I don't know whether to return this to B&H or wait to see if DJI can fix this with a firmware upgrade.
Here's the problem in video:
[youtube]http://www.youtube.com/watch?v=9BUilGeH74Q[/youtube]
In many parts of the world, the DJI Phantom 2 and 2 Vision won't fly straight when you take them out of the box. This is because the Naza flight controller doesn't do anything to adjust for magnetic declination. Instead, the Naza slowly adjusts to the declination over several minutes of flying. This wouldn't be so bad if the Naza remembered this adjustment on your next flight. But it does't and you have to start over every time. By the time the Phantom has figured out how to fly straight, you only have a few minutes of flying left.
Meanwhile, it is trivial to adjust automatically for declination. A few lines of code. Your GPS coordinates are used to find the local declination in a 1.6Kb lookup table and your compass reading is adjusted by that value. DJI, please fix this!
As of March 22, 2014, this impacts all Phantom 2 and P2V quad-rotors using the latest firmware (1.08). Multiple users have reported this problem in:
Western US and Canada, Northeastern US and Canada, Northeastern South America, Eastern Australia, New Zealand, Southern Africa.
[youtube]http://www.youtube.com/watch?v=9BUilGeH74Q[/youtube]
In many parts of the world, the DJI Phantom 2 and 2 Vision won't fly straight when you take them out of the box. This is because the Naza flight controller doesn't do anything to adjust for magnetic declination. Instead, the Naza slowly adjusts to the declination over several minutes of flying. This wouldn't be so bad if the Naza remembered this adjustment on your next flight. But it does't and you have to start over every time. By the time the Phantom has figured out how to fly straight, you only have a few minutes of flying left.
Meanwhile, it is trivial to adjust automatically for declination. A few lines of code. Your GPS coordinates are used to find the local declination in a 1.6Kb lookup table and your compass reading is adjusted by that value. DJI, please fix this!
As of March 22, 2014, this impacts all Phantom 2 and P2V quad-rotors using the latest firmware (1.08). Multiple users have reported this problem in:
Western US and Canada, Northeastern US and Canada, Northeastern South America, Eastern Australia, New Zealand, Southern Africa.
Bumping this up. We have almost 50 people reporting this issue. Watch the video in the post above. If you feel you have a similar issue, report it here. As soon as we get more than 50 people, I am going to work on getting DJI's attention. The more the better.
ianwood said:
Same problems I was having with my P2V except that it drifted to the Right and not the Left like you. I'm in New York City. I also noticed that many times after driving the battery down below 40 percent that it would fly straight, but recycle the power and bam, it's back to flying sideways again. Anyway my dealer told me to return it so waiting for a my replacement unit at this point.
BenDronePilot said:
You are the 7th person I've got on my list who has returned their Phantom because of this problem. Unfortunately, it is a bug in the firmware so your replacement will have the same issue. You're observation for it going to the right fits perfectly as the declination in NYC is -13 whereas LA is +12.
