Compass Calibration

[Parkerjh]

I've been flying drones for over 10 years, starting way back with the Phantom 2 and now using the Air 2S and Mavic 3. Lately something occurred to me: I haven't had to calibrate the compass in over a year.

Back when, it felt like I was doing the compass dance every other flight—spinning in a circle like a goofball in public spaces just to get airborne. Sometimes multiple times a week, depending on where I was flying.

Now? Nothing. Even when traveling to totally new locations or different states, the drones just fire up and fly with no complaints. Honestly, it's been so long, I forgot where in the menu the compass calibration even was. That used to be something I had to do by second nature.

Has something changed in the hardware? Are the compasses more shielded or self-correcting now? Or is the software just less sensitive or smarter about when calibration is actually needed? Even when getting new drones through the mail, it occurred to me, I haven't even calibrated them at that point.

Curious if others have noticed the same thing

 

[msinger]

Has something changed in the hardware?

I think what has changed is many people have figured out it's not a best practice, nor is it something that needs to be done before nearly every flight.

When should you be calibrating the compass? See more details here:

DJI Mavic Compass Calibration Guide | Mavic Help

Mavic Help is a site for help with DJI Mavic drones. Find the latest fixes, how-tos, guides, accessories, modifications, and more.

www.mavichelp.com

 

[Parkerjh]

Thanks for the reply, yes, I realize some people used to calibrate all the time. I was not one of them. I would typically only calibrate if I got a error on the controller saying calibration needed. My question is, I haven't seen that pop up in well over a year. Even when drones have been shipped from california, overseas, or on international trips. I just don't see it ever anymore.

 

[msinger]

I would typically only calibrate if I got a error on the controller saying calibration needed

Per the guide above, that's typically an indicator that you should not calibrate the compass. It normally occurs when the compass is/was near some type of magnetic metal source.

 

[Parkerjh]

LOL, I'm not looking for guidance on when to calibrate. I'm curious if DJI changed anything in hardware or software. I used to get compass warnings a few times a week. Haven't seen one in well over a year

 

[msinger]

LOL, I'm not looking for guidance on when to calibrate.

I'm not really offering guidance. Just pointing out the seemingly overlooked possibility that you may have been calibrating the compass unnecessarily.

I'm curious if DJI changed anything in hardware or software

Not that I'm aware of. This is how compass calibrations have functioned for some years now.

 

[Parkerjh]

Something changed. Across dozens of drones, it wasn't unusual to get at least a compass or two calibration notices every single week. Now I don't get them ever. That's what I'm just trying to drive to the root of regardless if one took the advice or not.

 

[Meta4]

LOL, I'm not looking for guidance on when to calibrate. I'm curious if DJI changed anything in hardware or software.

What DJI changed was the misinformation about compass calibration that they spread for years in their manuals.
Truth is that you've never needed to recalibrate the compass of your drones.

I used to get compass warnings a few times a week. Haven't seen one in well over a year

The warnings were that your perfectly functioning compass was telling you that the spot you'd placed the drone was close to a source of magnetic interference.
Moving away from that was the proper action and recalibrating a perfectly working compass wouldn't help.

If you really want some answers, the first post in this thread will give you an understanding about what compass calibration actually does (rather than what you might have believed) and when it might be needed (almost never).

A short explanation of compass function, calibration and errors.

Jun 9, 2020

BACKGROUND

The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information.

At the most basic level the purpose of the compass is to measure the earth’s magnetic field in order to find magnetic north relative to the aircraft heading. At any point near the earth the magnetic field is a single-valued vector quantity described by field strength and direction, and the compass comprises a 3-axis magnetometer aligned with the principal axes of the aircraft (x, y, z)...

• sar104
• Replies: 128
• Forum: Crash & Flyaway Assistance

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[MS Coast]

Something changed. Across dozens of drones, it wasn't unusual to get at least a compass or two calibration notices every single week. Now I don't get them ever. That's what I'm just trying to drive to the root of regardless if one took the advice or not.

I've flown only about a dozen drones over the past four years, but I can count on one hand the number of times I've seen a screen message suggesting a compass calibration and still have a couple of fingers in reserve. Nor have I heard of anyone else encountering those messages so frequently.

Perhaps you were experiencing a unusual problems for some some reason and have changed your operation practices?

 

[Parkerjh]

If you really want some answers, the first post in this thread will give you an understanding about what compass calibration actually does (rather than what you might have believed) and when it might be needed (almost never).

I simply wanted an answer of what DJI changed LOL. Regardless if it was needed or not, there are no longer any pop-up notifications. I was trying to understand what changed - the firmware or the hardware. Seems like firmware.

 

[Meta4]

I simply wanted an answer of what DJI changed LOL. Regardless if it was needed or not, there are no longer any pop-up notifications. I was trying to understand what changed - the firmware or the hardware. Seems like firmware.

It wasn't firmware or hardware.
Read what I posted because I've given you the answer.

 

[Parkerjh]

It wasn't firmware or hardware.
Read what I posted because I've given you the answer.

LOL, no you explained WHY there was a notification and the non-necessity of following it and what the calibration did or didn't do. That's all fine. Question was - why did the notification go away. So I am assuming that DJI realized it was unnecessary and changed the firmware to no longer have the pop-up warnings.

 

[Meta4]

LOL, no you explained WHY there was a notification and the non-necessity of following it and what the calibration did or didn't do. That's all fine. Question was - why did the notification go away. So I am assuming that DJI realized it was unnecessary and changed the firmware to no longer have the pop-up warnings.

I explained what you asked for.
There was no change in firmware or hardware.

I haven't recalibrated any DJI compass in over 10 years.
The only time my drones brought up DJI's poorly worded compass warning, that makes users think they had to calibrate the compass, was if I placed the drone close to steel items.

Or if you want another example of DJI's very badly worded warnings, I would get what appeared to be a comp[*** warning when launching a Mavic 3 pro in the dark.
Although the warning said to recalibrate the compass, it had nothing to do with the compass and recalibrating wouldn't make the warning go away.

Or DJI were so stupid about their false instructions about the necessity to recalibrate the compass every 30 days or if you travelled 50 miles from the last flight, that they actually made the Mavic 2 refuse to launch unless you (unnecessarily) recalibrated for either condition.
This is explained in the post I referred to above.

But to answer your question, compass calibration has never been required and there was no firmware or hardware change made about this.

 

[GadgetGuy]

I simply wanted an answer of what DJI changed LOL. Regardless if it was needed or not, there are no longer any pop-up notifications. I was trying to understand what changed - the firmware or the hardware. Seems like firmware.

If it makes you feel any better, I have been getting Compass Recalibration prompts for the RC Pro 2 controller, similar to the ones for the RC Pro. The only problem is that following the prompts on how to do the recalibration of the controller doesn't ever indicate that the calibration has succeeded, just like in the RC Pro, until it was fixed. Can't hurt to do figure 8's in the air with the RC Pro 2, but there is a missing calibration completed message. Controller appears to operate properly.

 

[journo]

Late to the party on this one, but I know what you're saying. I started flying in 2019 with a gen1 Mavic Mini and would get the calibrate compass warning fairly regularly. Most of the time I felt I probably was near metal, like launching from a corner with city bike racks or next to a building with outside fire escapes; I'd move away and recalibrate the compass.

I knew pilots here were saying the prompts were excessive and not unnecessary, but I always did a calibration as part of my rote routine as a pilot. I was trained by a pilot who flew both the dji phantoms and the old Mavic pro. His training included always calibrating the compass.

But starting with being issued a Mavic 3 and then a mini 3 pro I haven't been prompted since by the firmware which is current. Other issues which have been resolved: a) the Mavic 3 sets up a home point faster as satellite-capture speed has at least tripled b) Mavic 3 Remote ID failure with original phone-using RC has been solved by using only RC w/screen that came with the mini 3 pro fly more. At one time, I remember one phone/RC could be linked separately for different drones 3 or 4 years ago; I could pair a second drone but I'd only get limited flights before having to re-do the pairing, and it wasn't fluid going back to the original drone that was paired; I'd have to go through the whole thing again (hold down the battery button for 3 seconds until it honked...). Now, there is a quick firmware upgrade that automatically updates whichever drone is being toggle through the app. So I fixed the Remote ID lockout on the Mavic 3 and saved my boss money by not having to buy a second RC w/screen. Btw, according to a reddit post I found, I was locked out of remote ID because of the location services feature on my iphone, which was perplexing because it was always enable when using the Fly app. That's why eliminating the iPhone fixed the no-RID lockout.

So my guess is that all these things become streamlined and improved with firmware upgrades for next-gen drones and RCs. Whether dji figured out the prompts were no longer needed; or we just don't fly around that much metal anymore; or some other reason is a who-knows, but I am satisfied with the end results: no more pilot compass-calibrations appear needed.

 

[Meta4]

Most of the time I felt I probably was near metal, like launching from a corner with city bike racks or next to a building with outside fire escapes; I'd move away and recalibrate the compass.
... I always did a calibration as part of my rote routine as a pilot.

I was trained by a pilot who flew both the dji phantoms and the old Mavic pro. His training included always calibrating the compass.

The guy who trained you didn't understand what compass calibration actually does or when it might be required (almost never). His training was guided by the compass misinformation that DJI used to put in their manuals.

Read the first post from the link I posted in post #8 to learn the facts about compass calibration.

Other issues which have been resolved: a) the Mavic 3 sets up a home point faster as satellite-capture speed has at least tripled

It hasn't.
GPS acquisition times are the same as they have been for many years.
GPS acquisition times vary depending on a number of factors including how much of the skyview is obstructed, if you have traveled more than about 60 miles since your last flight and time since your flight.

Time to first fix - Wikipedia

en.wikipedia.org

I am satisfied with the end results: no more pilot compass-calibrations appear needed.

Compass calibration was never needed.

 

[GadgetGuy]

Great summary from the Time To First Fix Wikipedia link:

"The TTFFs for a cold start is typically between 2 and 4 minutes, a warm start is 45 seconds (or shorter), and a hot start is 22 seconds (or only a few seconds). In older hardware where satellite search is slower, a cold start may take more than the full 12.5 minutes."