The EKF has not finished starting

What ArduPilot says:

• EKF2 not started
• EKF3 still initialising
• EKF3 not started
• EKF2 still initialising

The EKF is ArduPilot's position and attitude estimator; one copy of it (a core, or lane) runs for each IMU it is told to use. “not started” means the copies have not been created yet: that happens about 1 s after boot and is put off while the GPS is still being identified. “still initialising” means a copy exists but does not call itself healthy yet: it needs 1 s of sensor data and 1 s more to settle, and on the ground its position and height must stay within 1 m of where they started.

What to do, most likely first

1. It was powered on moments ago.

   CheckWait 10 to 30 s with the aircraft still. “EKF3 IMU0 initialised” and “EKF3 IMU0 tilt alignment complete” show that it is moving on.

   FixNothing to change: arm once the message is gone.

2. The aircraft is being moved, or stands on something that shakes (a running car, a boat), so the estimate never settles.

   CheckThe message stays while you carry the aircraft and clears a few seconds after you put it on firm ground.

   FixStart it on firm, still ground. If it was moved a lot during start-up, reboot it there.

3. EKF3 is selected but not switched on, so it can never start.

   CheckAHRS_EKF_TYPE is 3 and EK3_ENABLE is 0.

   FixSet EK3_ENABLE to 1 and reboot.

4. The EKF is waiting for a GPS that the parameters promise but that never answered.

   Check“EKF3 waiting for GPS config data” repeats every 10 s in the messages.

   FixSee that message: wire the GPS, or set GPS1_TYPE to what is really fitted.

A barometer whose reading wanders (sunlight or wind on the sensor, a board still warming up) moves the height by more than 1 m and keeps the EKF “initialising”. Cover the barometer with open-cell foam and give a cold board a minute.

Parameters to look at

Where to do it:Setup & Tuning Guide