Since the last firmware update I've had to calibrate the compass every time I start the drone before it will start the motors.  Is this something DJI has implemented with the last update?  Before I went almost a year without having to calibrate and even when it said to calibrate, if I didn't the motors would still start.  Now they won't.  

What's up with this?

Conceptually you don't have to calibrate the compass before every flight, and if it is making you do so, this is the first time I have heard of it. Also, I have never heard of the aircraft not starting unless a compass calibration is performed. You need to look for other causes, were there any warnings on the screen? Perhaps uploading your flight log to: https://www.phantomhelp.com/LogViewer/Upload/ might help us see something.

Hello and good day WD9EON. I am sorry for the trouble this has caused you. Can you please try to colabrate the compass of the said drone once again. I will be posting and official DJI tutorial below on how to calibrate the said drone. In addition the reasons why you need to calibrate the compass of your drone are. First when the application prompts that the compass needs to be calibrated, the drone’s compass has suffered from interference as the aircraft was turned on in a place where there is magnetic interference. Make sure to fly the aircraft in an open area free of interference. Second when powering on the drone, ensure that the aircraft is at a standstill. If there is interference or the aircraft is powered on during movement, the compass’s orientation may be altered, and then recalibration is needed. Finally do ensure the flight stability, the application will prompt you to calibrate the compass when there is a need. Please follow the application and calibrate it. Please keep us posted on the said issue for us to help you further. Thank you.

DJI Stephen Posted at 4-7 14:35
Hello and good day WD9EON. I am sorry for the trouble this has caused you. Can you please try to colabrate the compass of the said drone once again. I will be posting and official DJI tutorial below on how to calibrate the said drone. In addition the reasons why you need to calibrate the compass of your drone are. First when the application prompts that the compass needs to be calibrated, the drone’s compass has suffered from interference as the aircraft was turned on in a place where there is magnetic interference. Make sure to fly the aircraft in an open area free of interference. Second when powering on the drone, ensure that the aircraft is at a standstill. If there is interference or the aircraft is powered on during movement, the compass’s orientation may be altered, and then recalibration is needed. Finally do ensure the flight stability, the application will prompt you to calibrate the compass when there is a need. Please follow the application and calibrate it. Please keep us posted on the said issue for us to help you further. Thank you.

https://www.youtube.com/watch?v=DHCDJKChXTE

I was mainly checking to see if the drone's updated firmware had been changed so that you have to do that.  I've had the drone for two and a half years, this just started after the last update.  

Thanks for the reply.

Are you using P3s with fw 1.9.200 ?

Is that with your P3s?

Try updating again.  That should not be happening.

Peterx Posted at 4-7 23:23
Is that with your P3s?

yes, found the problem, imu warming up, so by calibrating the compass it had been on long enough for the imu to come up to temp.  I'll have to recalibrate the imu at a lower temperature, it's been cool outside when I had my previous flights.  

Thanks for the help guys.

WD9EON Posted at 4-8 05:02
yes, found the problem, imu warming up, so by calibrating the compass it had been on long enough for the imu to come up to temp.  I'll have to recalibrate the imu at a lower temperature, it's been cool outside when I had my previous flights.  

Thanks for the help guys.

Glad you got it figured out.  A compass cal before every flight would become a nuisance fast.  Had to recal compass on my old P2V+ fairly often and got tiring.  So glad you're back in the air normally. (73 NA5N)

Geebax Posted at 2019-4-7 13:40
Conceptually you don't have to calibrate the compass before every flight, and if it is making you do so, this is the first time I have heard of it. Also, I have never heard of the aircraft not starting unless a compass calibration is performed. You need to look for other causes, were there any warnings on the screen? Perhaps uploading your flight log to: https://www.phantomhelp.com/LogViewer/Upload/ might help us see something.

You may not be familiar with the Phantom 4 V2. It does require the compass to be calibrated before taking off - it's nothing to do with any of the other systems.  I'm having a similar issue in that I have to recalibrate the compass before flight a little more than 2/3rds of the time - this isn't normal, and it wasn';t the case before.

I did calibrate the compass two times only,one time during activation the P3S at home and then one time i was more than 300 kilometers away from home. That should be for the P4  the same procedure.