*This post is applicable for the Mavic Pro as well as the Mavic Pro Platinum as their compasses are identical. 

If you own a DJI Mavic Pro or Pro Platinum and haven't heard of compass calibration, you must not own a computer. A correctly calibrated compass is very important, so let's first look at how to perform this task. 

To calibrate the compass on a Mavic Pro, follow these five steps:

1. Tap on settings>MC settings>advanced settings>sensors>compass
2. At the bottom, you will see “calibrate”. Tap on that.  
3. When prompted by the app, hold the aircraft horizontally and rotate 360 degrees. The status indicator lights should turn green. 
4. Now hold the aircraft vertically with the nose pointing down and rotate 360 degrees. 
5. If the status indicator lights turn red at any point, the calibration has failed. Move to a different location and try again. 

This subject gets brought up so frequently because of how important it is to take-off and fly without compass errors, but how often do you really need to calibrate it? Let's dive into what the compass does, common errors, and when you should calibrate.

When should you calibrate the Mavic Pro's compass?

If you have been around the drone scene for a few years then you have certainly heard many different answers to this question. Some say that you should calibrate the compass before every flight, while others say that that's unnecessary, or downright ludicrous. Most of us agree that it is smart to calibrate your compass when initially setting up your drone for the first time.

DJI recommends three instances when the compass should be calibrated on the Mavic Pro. 

1- If you receive a compass interference warning on the DJI GO 4 app, and it persists after changing locations, or if you notice alternating yellow and red blinking aircraft status indicator lights. 

2- If you travel further than 10 km (6.21 miles) from the last spot you flew.

3- If it has been more than 30 days since you flew your Mavic Pro.

Now, is it going to hurt your Mavic Pro if you calibrate it more often than necessary? No, it shouldn't, but it's also not necessary. Some say that you run the risk of throwing something out of whack when you calibrate a drone more than DJI's suggests to.

I have to say that my wife (Hailey) and I just did a road trip across the country and I did quite a bit of drone flying. Knowing full-well what DJI says about calibrating your drone if you travel more than 31 miles away from the last place you flew, I decided to conduct a little test.

I was only going to calibrate my drone if I got an error in the DJI GO 4 app. I should mention that I had a Phantom 4 Advanced with me and not a Mavic Pro, but the compasses between the two drones don't have significant differences, that I'm aware of.

After traveling for almost 3900 miles without not one compass calibration, I had not one compass error while flying. Granted, I didn't take off near any large metal objects, but still, I was impressed. Was this a responsible test that I conducted? Eh, probably not, but I was curious as to what would happen while constantly flying in a new location for about two weeks straight.

Related questions

Should you also calibrate the IMU while calibrating the compass? You have likely seen a few comments about the importance of calibrating the IMU on your drone. To find out how to do this, check out my post-DJI Drone IMU Calibration: When and How You Should Do It.

How to fix errors on your Mavic Pro vision position system. The vision positioning system often experiences errors as does the compass and IMU. To calibrate the VPS, check out my post-Mavic Pro Vision System Errors: How to Calibrate.

What is the role of the compass?

The compass gives the drone it's bearing, or in simpler terms, it lets the drone know which way the nose is facing. 

Why is this important while flying your Mavic Pro? Imagine that you are flying along and the drone suddenly loses connection from your RC. When the drone commences its RTH sequence, you're going to have some issues if the drone thinks that north is actually south.

Your Mavic Pro uses GPS and the compass when performing an RTH operation, but the bird will get conflicting information from these two systems if it doesn't know which way it's going.

What objects cause compass interference?

When calibrating the compass, it is extremely important to do so in an open area, free of obstruction. So, what kind of objects may cause compass calibration errors? 

Ferromagnetic materials, such as nickel, iron, and cobalt should be avoided. DJI mentions that cell phones often have ferromagnetic materials in them, and they suggest that you don't carry them in your pocket when calibrating the drone. I find this interesting that DJI specifically mentions cell phones, because, well, we have to use our cell phones (or tablets) to perform the calibration process. I guess they are saying “don't have three extra phones hanging out near the drone during the compass calibration, bud”. 

If you want to be overly cautious about the cell phone thing, you can have someone hold the RC with the phone/tablet while you have the drone about 10 feet away, or you can set the drone on the ground and walk over to it when you tap “calibrate” in the app. 

Here's a list of other objects that should be avoided while performing the calibration. Understand that this isn't a complete list, but it contains some of the most common objects we encounter in our environment. 

• Large metal structures
• Rebar (this may be an easy one to not realize you're close to)
• Parking structures 
• Steel reinforced basements 
• Cars
• Bridges (I attempted to calibrate in the middle of a very large bridge once. It didn't go well. I never did perform a successful calibration.)
• Scaffolding 
• Any electromagnetic fields
  

An area of discussion that doesn't seem to have a conclusive answer is smart-watches. Does that Apple or Samsung watch that you're wearing cause interference? Some people claim that their smart-watch makes a difference, while other's say that this is nonsense. 

I wear a Garmin watch, which is technically a smart-watch, but in a class where the Apple watch gets straight A's, the Garmin is more of a C kind of student. I don't seem to have any compass issues with my C average watch. 

I'd say that if you want to be on the safe side, take off the smart-watch. It would also be smart to perform a test to see if the watch causes problems.

You can actually see if the compass has any interference before you calibrate your Mavic Pro. To do this, open the DJI GO 4 app and go to settings>main controller settings>advanced settings>sensors>compass.

There have been so many discussions on where the best location is to calibrate the compass on a drone, and the truth of the matter is that it will be difficult to truly escape all forms of interference when you're in an urban environment. 

People have joked that the best spot to calibrate the compass on your drone is in the middle of a cornfield while you're in your birthday suit. But don't get too close to those to those gigantic metal rolling structures that water the field;).

Calibrate, or just move?

Something that I should note is that calibrating the compass near an object that is causing interference will not simply make the errors disappear. 

It may be tempting to see a compass error on the GO 4 app and immediately think that the remedy is to calibrate it. Don't do this. You are likely just too close to some metal object and the proper course of action would be to move a few feet away and see if the errors go away. 

Calibrating a compass that is already calibrated and in good working order only gives the drones compass an opportunity to get worse, not better. 

In-flight signs that you should calibrate the Mavic Pro's compass 

If you are cruising around with your Mavic Pro and the drone suddenly enters ATTI mode, there is a good chance that this is because of a compass or GPS problem.

You may also experience the “toilet bowl” effect, which is when the drone starts spinning on its axis instead of keeping its nose facing forward as it should. 

You may get a notification in the DJI GO 4 app while flying that lets you know there is compass interference, but this doesn't always happen. I was having problems with my drone a while back that we're a bit confusing at the time. 

I would be flying along with 18+ satellites and I would suddenly get an error that the drone lost GPS and was now entering ATTI mode. This was extremely frustrating as it would happen at the most random times, usually when I least expected it. In fact, I remember thinking that I would for sure lose GPS on one occasion when I only had 8 satellites. To my surprise, the drone remained in P-mode for the entire flight. 

This was frustrating conundrum because I didn't have much faith in the consistency of my drone, and I was alway on guard thinking that the AC would go into ATTI mode at any moment. 

When I started calibrating my drone on a more regular basis I noticed that this occurence would happen less often. Even if I didn't get a compass error, I would calibrate it and wouldn't lose GPS while flying as often. Does it still happen occasionally? Sure, but probably because I live in San Diego and it's difficult to escape all forms of interference when in or near a large city. 

If your Mavic Pro does enter ATTI mode while you're out flying, immediately panic! No, I'm totally kidding…panicking is the last thing you should do. When a drone is in ATTI (attitude) mode, you will need to fly it manually as GPS is not available. The drone will maintain its altitude but will drift with any wind.

This is a good reason to not fly too far from your location if you have a weak GPS signal or are getting compass errors. If the drone is just a tiny speck off in the distance, you will have to fly it back solely using the image transmission on your phone or tablet, and we all know how laggy that image can be.

If you lose GPS and happen to have the aircraft disconnect due to signal loss, you're going to be in a lot of trouble as the drone will have no clue how to return to home. If you're newer to flying or would like a refresher, I would strongly recommend reading Drone Flyaways: 14 ways to Prevent Them, and Best 17 Drone Flying Tips for Every DJI Beginner.

One last note about ATTI mode. I can guarantee with almost complete certainty that there will come a time when you have to fly in ATTI mode unexpectantly. To prepare yourself for this, you have a couple of options. If you own a Phantom or Inspire, you can toggle ATTI mode on the controller.  I would recommend practicing in ATTI mode while you're in an open area with a lot of room for error. It's not easy at first, but every seasoned drone pilot has a working knowledge of ol‘ ATTI and knows how to control her when necessary.

If you don't have a drone that allows you to manually enter ATTI mode, you may want to buy a cheap drone that will behave like a drone in ATTI mode, as this experience will go a long way in preparing you for the occasion when your Mavic Pro loses GPS.

How to check if there are compass errors on a Mavic Pro

Before you fly, the GO 4 app may display a compass error. If this is the case, follow the instructions listed at the beginning of this post and calibrate the compass in an area with no interference. Remember, there is a difference between the app telling you to calibrate the compass and that there is magnetic interference nearby. If the app is just letting you know that there is interference, move locations and see if the warning disappears.

Here is an example of the DJI GO 4 app telling me to calibrate the compass.

And here is an example of the DJI GO 4 app telling me that I need to try taking off from a different location and that there may be metal or magnetic objects nearby. 

You may see a yellow warning that says “compass redundancy switch”. The Mavic Pro has two compasses, and this message is letting you know that there is a problem with the first and the drone is switching to the second one. If you receive this warning, I would go into the settings and check the current status of each compass. Refer to the picture below for an example of the drone switching to compass #2 after having a lot of interference with compass #1. In this case, I was way too close to a metal object. 

You may also get a compass error while you are flying. If this is the case, I'd strongly recommend landing as soon as you can and proceed with calibrating the compass.

Alternating red and yellow blinking lights on the aircraft also indicate that a compass calibration is needed. 

Here is what the aircraft status menu should look like if there are no compass errors. 

If you continue to get compass errors despite trying to calibrate in multiple areas, I'd recommend trying this course of action:

1- Check for any firmware updates. Just remember that firmware updates are often large so complete the update when you are near Wi-Fi. 

2- If all firmware is updated and you are still getting compass errors, I'd try deleting and re-installing the DJI GO 4 app. In theory, this wouldn't rectify the problem because the compass is on the drone itself and not the GO 4 app, but there's a chance that the compass is completely fine and the app is just displaying unfounded errors.

Detailed Mavic Pro compass calibration steps

So if after changing locations the app is still prompting you to calibrate the compass, it's time to go through the calibration process. The five steps listed in the beginning are the main points, but here is where we get into the step-by-step instructions. 

Step #1- Bring your drone, remote controller and phone or tablet to an open area free of metal or magnetic objects. 

Step #2- Power on the RC, then the drone. 

Step #3- Tap on settings in the upper righthand corner. 

Step #4- Tap on main controller settings in the top left.

Step #5- Scroll down and tap advanced settings at the bottom.

Step #6- Tap on sensors. 

Step #7- Toggle over to Compass at the top.

Step #8- Tap on calibrate compass at the bottom. 

Step #9- Press start when prompted. 

Step #10- Begin the calibration by rotating the drone horizontally in a counterclockwise direction, parallel with the ground. You can stop when the status indicator lights flash green. 

Step #11- Next, rotate the drone on its side and rotate the aircraft 360 degrees vertically in a counterclockwise direction. Again, you can stop when the status indicator lights turn green. 

Step #12- Congrats, you've successfully calibrated the drone's compass! If the compass errors don't disappear, move locations and try to re-calibrate. 

Trevor's Take

You know, sometimes I just wish that nothing had to be calibrated on my drones and I could just whip them out wherever and whenever I wanted, but that's not technology. The amount of engineering that has gone into making these drones operate as well as they do is astounding. Really, this is what has set DJI apart from the rest. They've managed to put the best technology and engineering into their drones at an affordable price point. When you cram that much technology into a flying device that fits in the palm of your hand, it's asinine to think that the aircraft will fly perfect one hundred percent of the time without any maintenance (calibration). 

Have you had any compass errors on your Mavic Pro or Pro Platinum? What was your experience and were you able to resolve the issues? I'd love to hear about it in the comment section below!