If you’ve just bought the DJI Mavic Air or one of the company’s other consumer drones you may have encountered a problem with magnetic interference when trying to fly your drone for the first time. And your DJI Go 4 app might be telling you to recalibrate your compass, which if you’ve not done it before or are new to flying drones, might sound like a complicated procedure. It’s really not! And we’ll explain. But first let’s back up…
Like me with my Mavic Air, you’ve no doubt followed all the guides and connected it properly. You’ve linked your drone and handset and smartphone, so all three are communicating as they should. But when you try to lift off you receive an error message in the app about magnetic interference?
This happened to me with my Mavic Air. Sometimes you can get interference if there are electric cables overhead, or underground, but there was none in the locations I visited. In fact, I flew the DJI Spark in these spots last year without issue.
What’s the Cause?
Speaking to support at DJI, there are a number of things that can cause this error message. The aforementioned cables, for one. Having metal in your pockets. Or if you’re in a restricted area. Your smartphone can also cause interference if it’s not in airplane mode, I was told.
Chances are, though, there is a much simpler reason.
Drones, like any device that collects GPS information, rely on satellites to gather the data they need. Your drone might need to collect data from as many as 12 satellites in order to calculate your precise location.
If the drone can’t reach all of these satellites it will default to magnetic north rather than true north. And that’s where these interference issues can cause problems. What you need to do is re-calibrate your Mavic Air’s compass.
Now, if like me you scanned some of the DJI user groups and forums about this issue you will have seen people saying you should never re-calibrate your compass. It’s not something you want to do all the time, but in this instance, you should.
Think of it this way: your drone, when you take it out of the box, still thinks it is in the Chinese factory where it was manufactured. So you need to help identify it’s new home.
Look for a warning sign
As a general rule, only re-calibrate the compass of your Mavic Air (or other drone) when prompted to. When you get a magnetic interference warning from the Mavic Air, your DJI Go 4 app will suggest you re-calibrate your compass.
Tap OK to get started. The app will then show you a diagram of the Mavic Air and ask you to rotate it 360 degrees. It’s not entirely clear, though, how you should do this? In the video below I demonstrate how it should be done to properly re-calibrate your Mavic Air’s compass.
As you can see in the video, you need to hold the drone about a metre and a half off the ground with the bottom parallel to the ground. You then need to rotate the drone in a 360-degree circle with the bottom remaining parallel to the ground.
Once you’ve done this the app should recognise the motion and move you on to the next step. If not, repeat the first rotation again and the app will pick it up eventually.
For the second and final step in the Mavic Air compass re-calibration, you’ll need to hold the drone with its nose pointing toward the ground. Again, turn it around 360 degrees while keeping it in this downward position.
Your compass should now be re-calibrated and you’re ready to fly!
Calibrating the compass on a DJI Mavic Air: summary
- When prompted by the DJI GO 4 app to calibrate the compass, press OK.
- Hold the drone a metre and a half off the ground and rotate it in a 360-degree circle with the bottom parallel to the ground.
- Hold the drone with the nose pointed at the ground and turn it 360 degrees in this position.