On my first flight outdoors i noticed something strange when replaying the flight logs:
At some time the triangle indicator ( representing the deones heading ) did not match with the green "light" that is in front of the arrow ( see screenshot below) .

Shortly after there was a difference of about 40° i got a warning in the app saykng: aircraft interfered; Does that have something to do with it? Or was ist just telling me that the signal quality was bad ( was 800 metres out in ce mode ) .

I hope someone might help me

There’s no problem there with your compass, not sure about warning you received.

And why do they show different headings?

hallmark007 Posted at 12-28 09:52
There’s no problem there with your compass, not sure about warning you received.

Do you have any idea why there are two different headings shown?

Spark_Pilot_XxXx Posted at 12-28 13:25
Do you have any idea why there are two different headings shown?

If you mean the trace lines one is out one is back.

hallmark007 Posted at 12-28 13:46
If you mean the trace lines one is out one is back.

Nope i mean 1. The triangle and the direction it points at and 2. The green part in front of the triangle , which in my case (see screen) show two different directions.

Spark_Pilot_XxXx Posted at 12-28 14:09
Nope i mean 1. The triangle and the direction it points at and 2. The green part in front of the triangle , which in my case (see screen) show two different directions.

The direction is the point of your arrow and you can check this by starting your MM up and check that headings match .

Yes,

hallmark007 Posted at 12-28 14:18
The direction is the point of your arrow and you can check this by starting your MM up and check that headings match .

Yes, that is one heading that is shown but there is also annother one, the green Part in front of the arrow.

Spark_Pilot_XxXx Posted at 12-29 00:56
Yes, that is one heading that is shown but there is also annother one, the green Part in front of the arrow.

Your compass is fine, if you want to check preflight just preform exercise below before flying .


1/ start AC leave until you receive enough gps lock , 11 is a good number .

2/ if you get Compass interference turn off AC and move to another location,
without interference, if you still get warning preform calibration at safe location .

Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.

This exercise takes less than 2 minutes and is worthwhile doing before every flight,

One thing to remember is left stick pull down 100% if anything is not right, this is the quickest way to land your craft safely, and left down is easy to remember .

Hiya,

Interesting question, i am puzzled with this since i own a MM myself.

In flightlogs you can find 2 data streams about yaw data.
Aircraft and Gimbal yaw data. In all other DJI crafts the values for the 2 are almost the same.
Only while yawing you will see the values start to diverge but flying steady again the are the same again.

I have noticed that the gimbal data on a MM is sometimes absolutely not the same as Aircraft heading.
AFAIK the green area in the FlyApp is the direction the camera is pointing at. [EDIT see #18, learning all the time ]
But as the camera is pointing the same direction as the aicraft....what is 'wrong'....
My own MM gives the same value for both headings. (and indeed just checkes the green area : same as the craft, so looking fwd as the craft heading)

see 2 charts, #1 is my MM, #2 random picked other MM.

The fun is that when lines are equal and during flight a compass error pops up, than this is seen beacuse line are departing each other.

cheers
JJB

JJB* Posted at 12-29 06:22
Hiya,

Interesting question, i am puzzled with this since i own a MM myself.

https://www.phantomhelp.com/LogViewer/2GKUZASGXSEKYZD6JP1Y/

JJB* Posted at 12-29 06:22
Hiya,

Interesting question, i am puzzled with this since i own a MM myself.

okay! now i understand! when this happened to me i was flying in a straight line so i was not yawing. you said that this can result in a compass error so i am a bit worried now. at the time bouth indicators showed a different heading by 40 degree.

maybe you can have a look in my flight log posted above

Thank you!

Spark_Pilot_XxXx Posted at 12-29 07:38
okay! now i understand! when this happened to me i was flying in a straight line so i was not yawing. you said that this can result in a compass error so i am a bit worried now. at the time bouth indicators showed a different heading by 40 degree.

maybe you can have a look in my flight log posted above

Hiya,

Great flight, 3.5 % battery use per minute is a familiar value for me (as my MM)

No problems, don`t worry about your compass. Both lines are staying together during whole flight.
Your screenshot post# is record 10010 in my chart, gimbal yaw about 10 degrees to the right, wich is weird as in the screenshot is more to the left. Have to look in more files to find an explanation.
Always, as part of the after takeoff checks, check your compass; in the map view in the app and check the orientation indicator for correct indication.

Ps yellow line in the upper chart = heading values with no yaw input, so when oke it shows only horizontal lines.

Keep on the good flying,
Many happy landings,
Cheers
JJB

JJB* Posted at 12-29 08:00
Hiya,

Great flight, 3.5 % battery use per minute is a familiar value for me (as my MM)

many thanks to you!

i have got two last questions:

does the gimbal also has got a compass or is it using the imu to calculate its heading?

can you tell me where i can download the program you use for analysing the logs?

Spark_Pilot_XxXx Posted at 12-29 08:14
many thanks to you!

i have got two last questions:

Only one compass in the MM.

Not sure how this value is calculated, but when the compass data goes weird this value keeps the good value.

I use this for analysis > https://forum.dji.com/thread-203659-1-1.html
In about 2 weeks an update to be expected  ;-)

cheers
JJB

cheers
JJB

JJB* Posted at 12-29 10:50
Only one compass in the MM.

Not sure how this value is calculated, but when the compass data goes weird this value keeps the good value.

Alright, thank you very much!

The blue arrow represents the Aircraft location and direction. The green cone projected from the blue arrow represents the camera field of view / tilt angle of the gimbal. As you tilt the gimbal upward or downward, the green cone will rotate accordingly.

In my own testing: When the gimbal is at 0 degrees (horizontal) the green cone will project directly forward from the blue arrow, and while the gimbal / camera is pointed -90 degrees downward the green cone is projected at a 90 degree angle counter clockwise from the blue arrow. Tilting the gimbal upward to +20 degrees causes the green cone to shift clockwise from the tip of the blue arrow.

You can test this yourself by taking a short video where you rotate the gimbal from horizontal to vertical and back. Then compare the camera footage with the flight data center replay to see the green cone movement matches the vertical orientation of the gimbal.

djiuser_WFxwb3PkZgsK Posted at 12-31 02:09
The blue arrow represents the Aircraft location and direction. The green cone projected from the blue arrow represents the camera field of view / tilt angle of the gimbal. As you tilt the gimbal upward or downward, the green cone will rotate accordingly.

In my own testing: When the gimbal is at 0 degrees (horizontal) the green cone will project directly forward from the blue arrow, and while the gimbal / camera is pointed -90 degrees downward the green cone is projected at a 90 degree angle counter clockwise from the blue arrow. Tilting the gimbal upward to +20 degrees causes the green cone to shift clockwise from the tip of the blue arrow.

Wow really? That is fantastic ,i really started to worry about this because the difference of those two got to 45° at one point! Thank you very much for this information!

But on the other hand, why do they show this data like this? I mean this does not really make sence to show the tilt angle like this.

Spark_Pilot_XxXx Posted at 12-31 02:15
Wow really? That is fantastic ,i really started to worry about this because the difference of those two got to 45° at one point! Thank you very much for this information!

But on the other hand, why do they show this data like this? I mean this does not really make sence to show the tilt angle like this.

I agree the way they have chosen to display this is a bit confusing. I was thrown off by it at first and only figured it out when reviewing camera footage on my computer, side by side with the flight data center replays in the Fly app.

djiuser_WFxwb3PkZgsK Posted at 12-31 02:09
The blue arrow represents the Aircraft location and direction. The green cone projected from the blue arrow represents the camera field of view / tilt angle of the gimbal. As you tilt the gimbal upward or downward, the green cone will rotate accordingly.

In my own testing: When the gimbal is at 0 degrees (horizontal) the green cone will project directly forward from the blue arrow, and while the gimbal / camera is pointed -90 degrees downward the green cone is projected at a 90 degree angle counter clockwise from the blue arrow. Tilting the gimbal upward to +20 degrees causes the green cone to shift clockwise from the tip of the blue arrow.

hiya,

Thanks, checked it on one of my flights. You are absolutely right. Learning all the time!
But what a 'stupid' way of representing this, in a 2d view add a 3 axis up/down camera view.

cheers
JJB