hello there...
so after relcaibrating the imu on MY p3p ..altimeter now is +15 meters off after a 15 mins flight..
on auto take off it goes up to 1.3 meters then drops down almost touching the ground...


tested it at 20 meters and she holds up pretty well ....

is there a way to recalibrate altitude reading?

what firmware you on ?

Have you got VPS on ?


The baro can have a tolerance of a  meter or two and mine can be out upto 7m out at times but it does not affect flight.

hundleton1 Posted at 2015-9-20 12:00
what firmware you on ?

Have you got VPS on ?

1.4
vps on or off is the same..

IOS or Android? What version of OS?

ios, was 8.4 and now 9 ,, doesn't make a difference

I asked it from DJI and they said it is  barometer's feature. The barometer has 2cm/s of error.
If the flight time is 25min = 1500s, then the error can accumulate approximately to 30m = 2cm/s * 1500s

It is easy to fix problems, simply just say, it is feature....

jorski@netti.fi Posted at 2015-9-20 15:24
I asked it from DJI and they said it is  barometer's feature. The barometer has 2cm/s of error.
If  ...

You asked DJI! And you got a reply this fast!! You have good contact.
Asked them if the barometer is affected by an Imu cal?
As far as I know an IMU has to do with movement, like accelerometers etc I would think that IMU does not
affect Altitude reading, it would affect though Vertical Speed. My 2 Cents.
BTW 30M in 25 Minutes is enormous, of course I understand that this would be a maximum.

Bat

capbat Posted at 2015-9-20 22:30
You asked DJI! And you got a reply this fast!! You have good contact.
Asked them if the barometer ...

I get this answer a month ago, when I notice this issue. Of course, it take two weeks to get reply...

I have try several IMU cals, but the error is still the same. With the FW 1.1.9 and 1.04.0010 same error.

"It's a feature"

Must be a Micro$oft product.

capbat Posted at 2015-9-21 05:30
You asked DJI! And you got a reply this fast!! You have good contact.
Asked them if the barometer ...

The barometer/Altimeter is in the IMU.
Recalibrate the IMU when the phantom is cold (not been flown for a while) and do it immediately when phantom is turned on. The colder = more accurate. Don't put it in the fridge as this will mess the calibration accuracy.
You need to remember that the barometer uses pressure to measure altitude. This means the hotter the phantom, the more inaccurate the readings will be. I hope DJI has factored in the margin of error/tolerance based on heat inside the phantom.

my old p3p didn't have this 2cm/s Feature...... thats why i sold it....