Hi,

Does anyone know if its possible to calibrate the compass on the Mavic mini without using a screen?

I know for the Mavics and Phantoms you can toggle the flight mode switch on the remote controller a couple of times and initiate compass calibration, without a screen.

Thanks,
Emma

Why would you attempt to fly without a screen?
Is there any particular reason that you want to calibrate the compass?
There should be no need to do that.

Hello there Emma. Good day and thank you for reaching out. I will be posting the proper procedure in calibrating the compass of your DJI Mavic Mini. Thank you.

Labroides Posted at 7-21 20:21
Why would you attempt to fly without a screen?
Is there any particular reason that you want to calibrate the compass?
There should be no need to do that.

I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen. It also ensures the students are focused on the drone itself, and provides greater initial situational awareness for later flying. We do use screens eventually, but with bigger drones.

DJI Stephen Posted at 7-21 20:51
Hello there Emma. Good day and thank you for reaching out. I will be posting the proper procedure in calibrating the compass of your DJI Mavic Mini. Thank you.

[view_image]

Thank you.
I am really interested to know though if it can be done without a screen as I am a trainer who teaches students to fly using the mini's, initially, without a screen.  As I know you can do it with the bigger drones I was curious if it can also be done with the mini, even though the remote controller has less switches.

Emma2021 Posted at 7-21 20:56
I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen. It also ensures the students are focused on the drone itself, and provides greater initial situational awareness for later flying. We do use screens eventually, but with bigger drones.

DJI support on this forum is just copy & paste level of clueless. I read the manual entirely and there was no info on performing what you asked. I imagine if there is a way it would be in the manual so my answer would be no. Just have the compass calibrated with a screen then remove the screen and take off. It is your only option.

Emma2021 Posted at 7-21 20:58
Thank you.
I am really interested to know though if it can be done without a screen as I am a trainer who teaches students to fly using the mini's, initially, without a screen.  As I know you can do it with the bigger drones I was curious if it can also be done with the mini, even though the remote controller has less switches.

The good thing is that your compass always calibrates with these moves performed accurately without being disturbed by strong magnetic fields.

It always calibrates itself even if no such instruction that "you are going to calibrate yourself now" was given to the compass, so no need to worry ;) Just do the calibration moves physically on your drone. All you need is to power on the drone and turn it a few times in different axis. The only downside though, is that you can't know if your comapss is calibrated correctly after your calibration.

Guorium Posted at 7-21 21:28
DJI support on this forum is just copy & paste level of clueless. I read the manual entirely and there was no info on performing what you asked. I imagine if there is a way it would be in the manual so my answer would be no. Just have the compass calibrated with a screen then remove the screen and take off. It is your only option.

Cheers, yeah that's what we have been doing. Thought I'd throw the question out there though, just in case!

FriedChicken_II Posted at 7-21 21:29
The good thing is that your compass always calibrates with these moves performed accurately without being disturbed by strong magnetic fields.

It always calibrates itself even if no such instruction that "you are going to calibrate yourself now" was given to the compass, so no need to worry ;) Just do the calibration moves physically on your drone. All you need is to power on the drone and turn it a few times in different axis. The only downside though, is that you can't know if your comapss is calibrated correctly after your calibration.

Cheers, yeah its more of an instructional action i.e. this is how you would calibrate the compass if needed. We'll just use the screen.  

FriedChicken_II Posted at 7-21 21:29
The good thing is that your compass always calibrates with these moves performed accurately without being disturbed by strong magnetic fields.

It always calibrates itself even if no such instruction that "you are going to calibrate yourself now" was given to the compass, so no need to worry ;) Just do the calibration moves physically on your drone. All you need is to power on the drone and turn it a few times in different axis. The only downside though, is that you can't know if your comapss is calibrated correctly after your calibration.

That sounds just insane to me. People can lose drones if not calibrating correctly. Can you provide evidence for the claim?

Emma2021 Posted at 7-21 21:32
Cheers, yeah its more of an instructional action i.e. this is how you would calibrate the compass if needed. We'll just use the screen.

You don't need a screen to perform the calibration. Just twist the drone a few times in 3-axis after it's powered on should do the trick already.

The screen is only used to tell you:
1. if the compass is calibrated
2. how to do the calibration
3. see if the compass is calibrated after the calibration

And it has nothing to do with the actual calibration steps. It's just helpful, not necessary.

FriedChicken_II Posted at 7-21 21:40
You don't need a screen to perform the calibration. Just twist the drone a few times in 3-axis after it's powered on should do the trick already.

The screen is only used to tell you:

With every post you put on here you are gradually revealing that you do not know what you are talking about. Do everyone a favour and shut up.

Emma2021 Posted at 7-21 20:56
I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen. It also ensures the students are focused on the drone itself, and provides greater initial situational awareness for later flying. We do use screens eventually, but with bigger drones.

OK ... I can see why you are flying without a screen.
But I still can't see why you want to recalibrate the compass.
It's just not necessary.
What are you teaching about compass calibration and when it might be required?

Emma2021 Posted at 7-21 20:56
I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen. It also ensures the students are focused on the drone itself, and provides greater initial situational awareness for later flying. We do use screens eventually, but with bigger drones.

I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen.
Teaching students to fly the drone without a screen is a good idea, but that sounds like an odd way to do it.
If I was learning to drive a car, I'd like to have the benefit of the view through the windscreen and the instruments, before trying to drive blindfolded.
Wouldn't it be better to teach basic flight with the assistance of a screen view before pulling the plug on the screen?

Labroides Posted at 7-21 22:02
I am involved with training people to fly and we start by flying Mavic minis without screens so that they learn how to do it in case they ever lose their screen.
Teaching students to fly the drone without a screen is a good idea, but that sounds like an odd way to do it.
If I was learning to drive a car, I'd like to have the benefit of the view through the windscreen and the instruments, before trying to drive blindfolded.

It allows the student to focus on the stick controls and the drone, without multiple messages / wording / buttons on a screen. We only fly them in a small controlled box area, no further than 30m away.

Labroides Posted at 7-21 21:56
OK ... I can see why you are flying without a screen.
But I still can't see why you want to recalibrate the compass.
It's just not necessary.

We use drones that may have flown anywhere in the country, so if a drone flies on the west coast I would want to then calibrate it on the east coast before I flew it on the east coast (can be up to 12 degrees different in magnetic north)

Geebax Posted at 7-21 21:49
With every post you put on here you are gradually revealing that you do not know what you are talking about. Do everyone a favour and shut up.

You obviously doesn't have a clue on how electrical magnetometers work.
Any properly written drone control system would do compass recalibration not only just when you "initiate a calibration", but also all the time it's up and running.

The basic logic is: Your drone has a magnetometer, a gyroscope, and a gravity sensor. Magnetometer can tell the drone how strong the magnetic field is with current direction. The gyroscope tells the drone relative angles of movements. And a gravity sensor to tell where the known axis: Z axis (gravity) is.


By doing a typical compass calibration operation, what you're really doing is:

1. The G-sensor knows where the Z axis is.
2. So when you're turning your drone around, your gyroscope now knows the angle that your drone has turned. Which means that it has a relative direction axis system now.
3. With the magnetometer on your drone, it detects the magnetic field's strength in that specific direction that your drone is facing, constantly, during the period of turning drones.

So if you make a 360degree turn, the magnetometer would be able to figure out the strongest direction of the earth's magnetofield. Which, is the direction of magnetic polars. Now we only need to combine the relative axis got from gyroscope, and the axes that were generated from G and M sensors, you can get a calibrated compass.

And this is a constant process, the precission of the compass would get better and better during use if it's not interfered by other magnetic sources, because the more you turn your drone during flight, the more data it collects, and the algorithm can filter out those outliers better.

Emma2021 Posted at 7-21 22:08
We use drones that may have flown anywhere in the country, so if a drone flies on the west coast I would want to then calibrate it on the east coast before I flew it on the east coast (can be up to 12 degrees different in magnetic north)

We use drones that may have flown anywhere in the country, so if a drone flies on the west coast I would want to then calibrate it on the east coast before I flew it on the east coast (can be up to 12 degrees different in magnetic north)

There is so much misinformation and misunderstanding around compass calibration, and this is a big one.
Compass calibration has nothing at all to do with magnetic deviation or where you are or where the drone might have been previously.
Nothing at all, despite the myths you might have heard from people with no idea at all about how it works.
Compass calibration only does one thing and that's to identify and measure the magnetic fields that are part of the  drone, so it can ignore them and just react to the earth's magnetic field.
Once that's done, it's done.
If the drone flew properly on the west coast, it will fly properly on the east coast (or anywhere else) without recalibrating the compass.

Unless the drone is modified by adding or removing components, there is no need to recalibrate it.

I've flown in WA, NSW, Vic, Tasmania, North Qld, SE Qld, central Qld and NZ without ever recalibrating the compass in my drone.
Don't confuse your students by teaching them myths that have no basis in truth.
If you doubt what I've said, pm your email and I can give you much more details.

FriedChicken_II Posted at 7-21 23:26
You obviously doesn't have a clue on how electrical magnetometers work.
Any properly written drone control system would do compass recalibration not only just when you "initiate a calibration", but also all the time it's up and running.

Gravity Sensor? Really? They do exist, and are called gravimeters, but are far too large and delicate to be flown in a drone. They are most certainly not fitted to any of DJI's drones. Like I said, you don't know what you are talking about. And your dissertation on how the compass calibration process works is completely wrong. Read post #18 to get a better description of the process. I do have significant qualifications in electronics, but I don't intend to detail them for you. Finally, I repeat, shut up and stop confusing people with your lack of knowledge.

Geebax Posted at 7-22 16:19
Gravity Sensor? Really? They do exist, and are called gravimeters, but are far too large and delicate to be flown in a drone. They are most certainly not fitted to any of DJI's drones. Like I said, you don't know what you are talking about. And your dissertation on how the compass calibration process works is completely wrong. Read post #18 to get a better description of the process. I do have significant qualifications in electronics, but I don't intend to detail them for you. Finally, I repeat, shut up and stop confusing people with your lack of knowledge.

do you understand that even your mobile phone has an acceleration meter?

and basically that's used to figure out where the earth is. So basically that's a gravity sensor in the context.

I'm just amazed by your arrogance of being so confident but yet knowing literally nothing. I've wrote code for multiple working farming drones' onboard firmware, so tell me, what do you know about how the drone fly itself?

Let me explain how the compass in your drone, your phone, or almost any digital devices is working today.

1. Your device usually has a 3-axis magnetometer. A 1-axis magnetometer also works but needs to be calibrated more frequently and it's almost not used anymore. The magnetometer is used to detect the direction of the magnetic field around it. The 3 axes magnetometer can figure out where the magnetic field is pointing and the strength of it immediately, while the 1 axis magnetometer needs other supporting informations but also can complete its job. The meters would generate a magnetic vector. We need the magnetic vector to figure out real world yaw angles.

2. Your device has an acceleration meter, or accelerometer, or gravity sensor. This is also a 3 axis sensor that is used to figure out the direction of gravity, or, the pitch angle of your drone.

3. Your device has a gyroscope. That is used to determine the angles that you've turned your drone. As we've known the pitch angle, now we also knows relative roll and yaw angles. Combined with realworld yaw angles that we've metered with the magnetometer, we know all angles on all axes now. However,

4. Your drone has other parts that may generate interference on the magnetic field. This usually can be considered as a constant interference so we can subtract it by using "calibrating compass".

5. The firmware of your drone keeps track of the "confidence level" of the compass. If it gets close to a strong magnetic interference source, this would be recorded, and the firmware would immediately lower the confidence of the compass. When it's lowered too much that the firmware cannot trust the compass anymore, the pop up of "need to calibrate" would appear.

6. Usually when you're not very close to the polar axis of earth, your turning angles recorded on gyroscope should be matching close to the turning angles recorded on your magnetometer. When these two doesn't match close enough, the firmware would lower the confidence of compass.  When you get further away from the magnetic source, when you're turning the drone, the firmware constantly calibrates the compass and calculates the difference between the two angles measured. When the two angles are close enough again, considered by the firmware, it regains the confidence on compass.

7. In an ideal world without interference your 3 axes magnetometer's sampled magnetic vectors can build up a sphere around your drone. Because, when you're turning the drone, without any interference, the magnetic field of earth doesn't change. So the metered magnetic vector is always pointing to north, and has a constant strength. What happens when you turn your drone in 3 axes? This vector fills a sphere-like space.

8. In real world, due to the magnetic interferences that is close to your drone's sensor, the vector might change its direction and strength when turning your drone. Now the sampled vectors can only build up a strange potato like thing. Thankfully due to that these interfering parts on your drone also turns with your drone, this means that it builds a constant magnetic interference field that can be subtracted easily, if sampled in all axes/directions.

9. So there're two cases that you need to recalibrate the compass:
       a. the firmware lost track of compass confidence (happened to many DJI Mini 2 pilots in earlier firmware). Things like power-off can cause this to happen if the function was not implemented properly.
       b. the firmware lost confidence on compass due to mismatches between angles of magnetic vectors and attitude vectors.

10. But, anyway, you don't need ANY SCREEN to do the calibration. As I have stated, the calibration is a constant and automatic process.
11. If you turn your drone 360 degrees around 3 axes when it's powered on, then the compass would be able to filter out those interferences on drone and rebuild the confidence on compass when there's no strong magnetic interference around.


Read this before you post again:
https://docs.microsoft.com/en-us ... redirectedfrom=MSDN


I don't own a Mini 1, but I do own a Mini 2 and it was constantly requiring for calibration after almost every reboot due to firmware issues. I don't even use the calibration function in DJI Fly, simply turn the drone on 3 axes and the pop up is gone.

FriedChicken_II Posted at 7-22 17:12
do you understand that even your mobile phone has an acceleration meter?

and basically that's used to figure out where the earth is. So basically that's a gravity sensor in the context.

"I'm just amazed by your arrogance of being so confident but yet knowing literally nothing. I've wrote code for multiple working farming drones' onboard firmware, so tell me, what do you know about how the drone fly itself?"

You say I literally know nothing, and you have deduced this by reading my posts in which I have not put forward any technical theories? You are an idiot, and worse still an opinionated idiot. You have no idea what I know, and I have no intention of enlightening you. I will say however that if I was to give you my employment history over 50 years of working in electronics, you might be tempted to shut up.

Your rambling narrative about the compass ignores a simple yet basic fact, there is nothing in the procedure outlined by DJI that allows you to set a given, and known, direction, therefore it cannot be used to 'calibrate' the compass.

Geebax Posted at 7-22 19:54
"I'm just amazed by your arrogance of being so confident but yet knowing literally nothing. I've wrote code for multiple working farming drones' onboard firmware, so tell me, what do you know about how the drone fly itself?"

You say I literally know nothing, and you have deduced this by reading my posts in which I have not put forward any technical theories? You are an idiot, and worse still an opinionated idiot. You have no idea what I know, and I have no intention of enlightening you. I will say however that if I was to give you my employment history over 50 years of working in electronics, you might be tempted to shut up.

Your rambling narrative about the compass ignores a simple yet basic fact, there is nothing in the procedure outlined by DJI that allows you to set a given, and known, direction, therefore it cannot be used to 'calibrate' the compass.

What does this nonsense even mean?  Why people need to set a given and known direction?
All those sensors were placed physically in specific placement and therefore all the directions were already known to the drone firmware. The gravity vector is always pointing downwards, the magnetic vector is always pointing close to magnetic north, all that the firmware need to do is to combine with gyroscope data and filter out the interference.


Please do us a favor learn something instead of ranting nonsense.

FriedChicken_II Posted at 7-22 20:33
Your rambling narrative about the compass ignores a simple yet basic fact, there is nothing in the procedure outlined by DJI that allows you to set a given, and known, direction, therefore it cannot be used to 'calibrate' the compass.

What does this nonsense even mean?  Why people need to set a given and known direction?

"The gravity vector is always pointing downwards, the magnetic vector is always pointing close to magnetic north"

If you were truly calibrating the compass, which was a procedure they used to carry out in aircraft when magnetic compasses were commonly used, it was normal to mark a section on the airfield that was guaranteed to point to magnetic north. When does DJI require you to do this in 'calibrating' the compass? The answer is they don't and this is why the 'calibration' procedure is NOT calibrating the compass.