When trying to do the advanced IMU calibration, I keep getting a pop up message telling me my controller is too hot and to let it cool down for 5 minutes and then recalibrate again. It finishes the routine with a green checkmark in the box, but I did this at 70 degrees F and then let it cool down to 55 degrees F and still get the message even though I do the calibration routine right away. I even changed batteries in case a battery was getting hot. I have not yet flown the new drone, it is right out of the box. P2V+ V3.

Thoughts?         Barney

Barney,  I don't know where you are located.  If you are in the Northern Hemisphere then set your Inspire outside and let it acclimate and then do the calibration.  If you are south cool it down under the A/C.   

im sorry but i dont believe that a brand new drone that has never been flown has to be cooled down with an AC unit or sat outside to reduce its temp before you do an IMU calibration.  a non-flown drone should be able to be calibrated at room temp (<70C).  i would be interested in hearing the scientific basis of that, because without that basis, i would argue that if it were truly necessary, that is a poor design.

and we've had a handful of people on this forum that have had perfectly successful calibrations even after flying and not letting it cool down.  

gnixon2015 Posted at 2015-2-23 13:25
im sorry but i dont believe that a brand new drone that has never been flown has to be cooled down w ...

Some of them are gone now.

Observer 2 Posted at 2015-2-23 13:39
Some of them are gone now.

Hopefully they will all come back.

Barney,

Why are you doing an Advanced IMU calibration when you have not flown your Phantom yet? You should only do this if advised by the System that it is way out of calibration, or you have stability issues in flight.

There is a thread here you should read on yaw drift and what happens if you do an advanced IMU calibration without having an exact level reference point to use.

As for the so called masters the statement "its a bug and ignore it" is pretty immature thinking. This nonsense has propagated from the Kitchen Table video on IMU calibration. The video does not refer to anything related to correct levelling and make the bug statement on the IMU overheat.

I have never seen a bug that was so explicit in its wording. Now it may pop up at the wrong time, and the IMU may not be overheating, but how would you know if its a valid warning or not?

Should anyone need to do an Advanced IMU calibration do so after the Phantom has been powered down for over 20 minutes and do the calibration immediately when switched on. That way you have the best opportunity to get an accurate calibration without an overheat mis-calibration.

Cheers

bjr, i get what you are saying that IF you have been flying and your phantom is hot and you immediately plug it in and attempt an IMU that you shouldnt ignore warnings that it is too hot.  the issue I have is that barney has not ever flown.  while i get your point about that being a time that you prob shouldnt calibrate, and agree with you, i dont think that there is any comparison to these two situations:

1.  been flying over and over trying to calibrate in between and getting error msgs and 'ignoring' them.
2.  never flown before and needing to 'cool it down' to do a calibration.

unless you live in a tropical area and it is 100F in your computer room, there should be no reason to have this message coming up when you attempt to calibrate.  that is either a design flaw or a bug of some kind.

bjr981s Posted at 2015-2-23 20:27
Barney,

Why are you doing an Advanced IMU calibration when you have not flown your Phantom yet? You ...

When I got my Phantom, straight out of the box, the gyroscopic mod was 0.08.  It was within limits but it said closer to 0.0 would be ideal.  I ran the IMU and got the TO HOT MESSAGE.  As it was in the high 80's outside, I put it in the refrigerator for 20 minutes and then connected again.  I still got the TO HOT MESSAGE.  I ran it anyway after clicking ok and got a 0.2 after.  More closer to ideal.

gnixon2015 Posted at 2015-2-23 20:39
bjr, i get what you are saying that IF you have been flying and your phantom is hot and you immediat ...

This issue / bug is only on the Windows Version not the Mac version of the assistant software.

You cannot bypass the warning on the Mac version.

When the Phantom powers up the IMU goes into "ready" state and will stay there for about 2 to 3 minutes. This is the only time you can do a calibration. After the "ready" state it goes to "Idle"

The documentation is clear that the IMU needs to be in the state "ready" for the calibration.

People are assuming that it would take a long time for the IMU to reach a temp that would make calibration inaccurate.

The change in state takes 3 minutes max. So I guess the temp is too hot after 3 minutes?

I do not really understand how this process is meant to work or what the potential issue are in forcing a calibration when its too hot.

I'm just suggesting if you can follow the documentation and get a calibration by the rules, you should be in a much better place.

Cheers

Observer 2 Posted at 2015-2-23 20:54
When I got my Phantom, straight out of the box, the gyroscopic mod was 0.08.  It was within limits ...

When I got my Phantom, straight out of the box, the gyroscopic mod was 0.08.  It was within limits but it said closer to 0.0 would be ideal.  I ran the IMU and got the TO HOT MESSAGE.  As it was in the high 80's outside, I put it in the refrigerator for 20 minutes and then connected again.  I still got the TO HOT MESSAGE.  I ran it anyway after clicking ok and got a 0.2 after.  More closer to ideal.

What makes you think that the lower the number the better?

The documentation says it should be between 0.0 to 1.5. your .8 is right in the middle where it should be. Remember its a mod value not an absolute value. I think you will find that the closer to 0 is better for the absolute values.

It also says if the mod value is 1.5 to 3.0 you should do a basic calibration.

Only if its over 3 should you do an advanced calibration.

When the Phantom powers up the IMU goes into "ready" state and will stay there for about 2 to 3 minutes. This is the only time you can do a calibration. After the "ready" state it goes to "Idle"

I've got to take my clock back to the store, it must be broken.  I connected my Phantom to the PT2 program and went to the advanced tab for the IOC calibration and it stayed in ready for 17 minutes before I turned it off.  The gyroscope mod was bouncing between 0.0 and 0.3.  The acceleration was a rock steady 1.00 and the compass was bouncing between 1388 and 1399.

When it comes off the ground, it is rock steady with no drift.  My other one will drift a foot or 2 with a 0.7 for the gyroscope.  The gyrosvope is a little more out of level than my primary one, resulting in the drift.
Don't get me wrong, I'm not arguing with you, I'm just telling you what mine do.

Thanks everyone. I thought that I would simply run through all the calibration procedures before starting. I couldn't imagine why would it hurt?  None-the-less, here is the response from DJI directly. I hope I don't have to fly in next to freezing whether for it to be calibratied!
Thanks.    Barney

The message that you are receiving is common and not something to worry too much about. Generally, one thing that we suggest in these situations is placing the unit in a cool place, such as your refrigerator, for about 5 minutes. This will give the unit a chance to properly cool. Once you connect the Phantom back to your computer and continue with the IMU calibration, you should be able to proceed, without any issues.

If you continue to get the message, please let us know, as it could be an indication of an internal issue.

sorry guys, i dont mean to sound like a jackhole, but i find it ridiculous that someone would suggest that a NON-FLOWN phantom should be put in a refridgerator in order to successfully calibrate the IMU.  sigh.    
barney, i also agree, however, that i would not recommend doing a calibration until you fly first.  my phantom has had 20-25 flights and has never been IMU calibrated.  it sits still like it is on a freaking pole and has ever since it came right out of the box.  until you KNOW it is wavering, i wouldnt recommend adding another potential variable into the mix.  just my two cents.

The DJI response is STUPID!!! DO NOT put it in refrigerator, moisture will condense all over internal components when you remove it!!!!

Just do it on a day you have not flown and ignore the warning.

gsp171@mchsi.co Posted at 2015-2-24 02:55
The DJI response is STUPID!!! DO NOT put it in refrigerator, moisture will condense all over interna ...

read above, he has NEVER flown.  so it has never 'heated up' beyond room temperature LOL

gnixon2015 Posted at 2015-2-24 02:54
sorry guys, i dont mean to sound like a jackhole, but i find it ridiculous that someone would sugges ...

Thanks G. I would not put my phantom in the fridge, although I must admit I thought about it.
It was 70 degrees in the house, I took it outside for half an hour where it was 55. Took it back and got the same error message.
As for calibrating before flying, duly noted. I just kinda thought that it is either calibrated or it's not. It shouldn't hurt to calibrate an instrument that is already in calibration. If their calibration routine is that much better than the one they give us, than they need to rethink that. I'll give it a shot this weekend if it will ever stop raining.    Barney

Observer 2 Posted at 2015-2-23 21:23
When the Phantom powers up the IMU goes into "ready" state and will stay there for about 2 to 3 minu ...

Thanks for the info on the ready state timing.

Maybe I have an issue with mine. It flicks from Ready to Idle.

I notice when its in Idle I can get it to go to ready by doing a Check IMU status?

Mine is P2V + V3

i believe the 'check IMU status' overrides the IDLE state and puts it back in ready state again for 2-3 mins at which point it will go idle.  actually i think that is one of the purposes of that button is to reactivate it after idle if you want to calibrate without powering it off and back on again.  

I have calibrated mine a couple times when it was not needed, no harm, I get the hot message every time and just ignore it

Seems as though doing an advanced cal wouldn't be the best thing to do unless you are sure you have the phantom setting perfectly level in all directions during the cal.  Otherwise, you could get unwanted take-offs and such where it will lean one way or the other.

dchicora.comcas Posted at 2015-2-25 18:58
Seems as though doing an advanced cal wouldn't be the best thing to do unless you are sure you have  ...

If it is already acting strange, or the mod values are wild numbers, only then would I do a calibration.

Couple comments...
First, I am new to flying quads-- I've flown a cheapie twin-rotor and quad (and still learning how to fly a CP heli). I found a guy selling a NIB P2V+ for a good price, so I took the plunge.  After installing prop-guards and spending hours getting all the batteries fully charged, I was ready to try a flight following the Quick Start Guide. Everything went great until I tried to do the CPC to start the motors-- NOTHING (but 3 red flash error code).

After trying to look up what can cause that error code in the User's Guide (not super helpful), I started searching the Internet.  Downloaded the Assistant software for my Mac and hooked up the Phantom.... It indicated I needed to do the IMU Advanced Calibration.   I live in Minnesota/USA and summer temps here are 90F+.  I got the "Controller Too Hot" message, but nothing I did helped (take copter to shade, take inside to A/C).
The advice about "Clicking through" did nothing -- I could not get the motors to start.  Went down the road of updating all the firmware on everything. Still nothing.  I'm getting a sinking feeling that I spent $$$ on an impressive paperweight and starting looking for a source for a replacement IMU.

My wife happened to be traveling and headed out very early the next morning. On a lark, I went outside and attempted the Advanced Calibration again (60F temps)--  calibration took 30-40 seconds and completed with no errors. Motors started and my first flight went perfectly!

Take-away:  
-- Very disheartening for a new owner to have to go through all of this to get a basic first flight.
-- There is lots of voodoo in this thread-- the error messages matter and so does the ambient temperature!
-- The IMU may be hosed out-of-the-box and need calibration.

Most IMU need to be don't after any major shipping and that how they get to the store sniping can scramble a sensor or sensors and then calibration is required. This is controversy over this but I a, quoting what DJI technicians have told me and 90% of the guys they had repairs and their quad shipped back to them.

The only time I've had to recalibrate my IMU was after checking the Phantom as luggage on a flight.  So that jives with what roy is saying.

Do you guys use any thing special to make sure the surface you have the Phantom on is absolutely level or is close good enough?
I do IMU calibrations on my kitchen table which I checked with a regular builders level.   Is that good enough?