DJI Inspire Compass Calibration Guide
Why should the Inspire compass be calibrated?
A good compass calibration is important to ensure a safe, controlled flight.
The only purpose of compass calibration is to measure the components of the aircraft's magnetic field so that they can be subtracted from the total measured magnetic field. Rotating the three-axis magnetometers allows the aircraft's flight controller to separate the surrounding magnetic field from the magnetic field of the aircraft itself. It's able to separate them since the aircraft's magnetic field remains constant (in the frame of reference of the magnetometers) while the surrounding magnetic field rotates.
No amount of measuring will allow the aircraft's flight controller to determine the deviation or declination at a location (since it has no idea where true north is located). Declination is determined from a global declination model within the firmware. There is no way to compensate for deviation since it's unmeasurable. That explains why taking off in areas of significant magnetic deviation will lead to unstable flight.
The Inspire can only detect when the compass is providing extremely poor (implausible) data. This typically occurs if you place it near a strong magnetic field. It will flash red and yellow lights and the Inspire will indicate a compass error in the app.
Note: The lack of a compass error does NOT mean your compass is working and calibrated properly.
You can view the current compass interference in the "Main Controller Settings" --> "Advanced Settings" --> "Sensors" section of DJI GO. The colored bars should be in the green (Excellent) range when the Inspire is in a location that is away from magnetic influences. If the bars are in the red (Poor) range or close to it, move the Inspire to a different location and check again. If the compass interference is still in the red (Poor) range or close to it, the compass could need calibrated or it could be magnetized/damaged.
Note: A good compass interference value does NOT mean your compass is working and calibrated properly.
When should the Inspire compass be calibrated?
You do not need to calibrate before every flight and in some cases you definitely should not calibrate. That doesn't mean you shouldn't ever bother doing it. It only takes one time for it to go very wrong.
Note: The ideal place to calibrate is a wide open location that is free of anything metallic within a 20 ft radius. Keep away from drainage pipes, irrigation systems, rocks, sidewalks (or other concrete structures), etc.
DO calibrate the Inspire compass if:
- Compass interference values are out of whack or DJI GO is displaying a compass error (check area for magnetic metal objects before calibrating)
- The Inspire is circling in flight while hovering in place (also check for other possible causes)
- New metallic equipment has been attached or removed from the Inspire (e.g. GPS tracker)
- If you just degaussed your compass (don't degauss the compass unless instructed)
DO NOT calibrate the Inspire compass if:
- The Inspire is near concrete, buildings, and/or hidden or overhead power lines/pipes/etc.
- You're indoors, on a paved surface, on a stone surface, on the beach, on a boat, on a balcony, near a car, near speakers, etc.
- There are magnetic metallic objects near the Inspire or you're not certain there are no such objects nearby
How to Calibrate the Inspire Compass
- Remove all metal from your person that could potentially be held near the Inspire while you're calibrating (e.g. watch or rings).
- Find a location on grass or dirt and not on concrete or asphalt (unless you know the concrete or asphalt does not contain rebar).
- Power up your Inspire and any attached accessories (e.g. GPS tracker).
- Wait until your Inspire is ready to fly.
- Click the "Calibrate" button in the "Aircaft Status" section of DJI GO. If the "Calibrate" button does not appear there, then you can calibrate the compass from the "Advanced Settings" section of DJI GO.
- Confirm the rear Inspire arm lights are solid yellow.
- Pick up the Inspire and turn it smoothly and steadily a full 360 degrees (or a little bit more) until the rear Inspire arm lights turn solid green.
- Note: While it's okay to turn the Inspire in your hands, it's easier to hold the Inspire steady and turn your body in a circle (like this).
- Point the front of the Inspire straight down and turn it smoothly and steadily a full 360 degrees (or a little bit more) until the rear Inspire arms start flashing green.
- Note: Don't be concerned if the Inspire gimbal reacts poorly to being face down. Continue to smoothly and steadily turn the Inspire. If for any reason you do not complete any of the above steps smoothly and evenly, restart the process.