Everytime i use my backpac to carry my P3P I need to do a IMU calibration when i get on location.  Is this normal?

Not at all.
Do you have it in the back of your car by huge speakers or something?

And are you using the hardshelled,  foam lined backpack?

The speakers only affect the compass.
The IMU is the sensors for gyro/accelerometer and barometric. This is only needed to be calibrated after nasty bump or massive climate change (decrease warm up times).

Are you tossing your backpack into your boot?
Has your car got lowered springs or on hydraulics that bounce up and down?

Seems like mine always says IMU calibration required when I take mine in my backpack.  I just let it warm up and it settles in and doesn't actually need one.  I check the compass and gyro values to ensure its really doesn't need one...  Only did the IMU calibration when I first got mine

There is a problem somewhere; I have been using a photography backpack to transport my P3P for hundreds of flights, never had this issue.

I've only used the backpack on walking trails near my house.  Havn't been near a car for speakers.  I was out again today.  Walked about 45mins with pack on my back and when I got to location I had the same issue.  Reset P3P three times before the IMU error went away.  The temp is about -15C here at the moment.  Wonder if that as anything to do with the error.

[RCG]Balthazar Posted at 2016-2-14 15:47
Not at all.
Do you have it in the back of your car by huge speakers or something?

No speakers, just walking (Snowshoeing) with pack on back.  -15C here not sure if the temp would have anything to do with it.

Cold has affect on your paired device, as well, to your intelligent flight battery packs.  I only calibrate my IMU after a new update of firmware or Go app improvements.
So I am Not quite sure why you are getting this calibration alert?

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