Maiden flight IMU Error

[m00n.patrol]

Hey All

First post but lurking for quite a while. Just got my P3A a few days ago. Upgraded firmware all was good. Took it for a quick up and down and that was it. All was well.

This morning I upgraded to the latest and greatest firmware and started getting an IMU error afterwards. Rebooted, all gone. Tried a few more times and gone.

Took it out for an actual maiden flight. Flew through one battery without issue, although my iPad overheated so I brought it back in manually. Went to put in another battery. IMU error. Came home, no IMU error. Let it sit on while I went thought some video and pics and discharge, swapped batteries, IMU error.

Ok I can take a hint... I need to calibrate the IMU... but can someone explain why, a little more in depth? Let me add that it is very hot today... about 100 degrees. I have read various conflicting things about IMU calibration. Is this just a heat thing or is there something else in play here?

 

[bobmyers]

Hey All

First post but lurking for quite a while. Just got my P3A a few days ago. Upgraded firmware all was good. Took it for a quick up and down and that was it. All was well.

This morning I upgraded to the latest and greatest firmware and started getting an IMU error afterwards. Rebooted, all gone. Tried a few more times and gone.

Took it out for an actual maiden flight. Flew through one battery without issue, although my iPad overheated so I brought it back in manually. Went to put in another battery. IMU error. Came home, no IMU error. Let it sit on while I went thought some video and pics and discharge, swapped batteries, IMU error.

Ok I can take a hint... I need to calibrate the IMU... but can someone explain why, a little more in depth? Let me add that it is very hot today... about 100 degrees. I have read various conflicting things about IMU calibration. Is this just a heat thing or is there something else in play here?

No 1, IPADS don't like 100 degree weather-- It will start dropping signal. Turn off all the processing in the app-- airplane mode-- fly in the shade or in the car with the ac going.
With regard to the IMU-- upgrade is a must after a Firmware update-- no I don't know exactly why, but from participating in this forum, I would Upgrade firmware and always follow that with an IMU calibration and gimbal calibration. You will get some other chaps chiming in here.

 

[GadgetGuy]

Also, do not recalibrate the IMU in 100° heat! Your warm up times will go from 15 seconds to minutes on every flight thereafter! Put your bird with battery removed in front of an AC unit for 15-20 minutes, along with the battery next to it, to get them both as cold as possible, while setting up the app with the transmitter on the calibrate IMU screen, with a previously perfectly levelled surface away from all metal ready to use for the calibration. Then, put the cold battery inside the cold bird and immediately power up the battery, and do the IMU calibration. Mine went from 5 minute warmup times to 15 second warmup times by following this procedure!

 

[m00n.patrol]

No 1, IPADS don't like 100 degree weather-- It will start dropping signal. Turn off all the processing in the app-- airplane mode-- fly in the shade or in the car with the ac going.
With regard to the IMU-- upgrade is a must after a Firmware update-- no I don't know exactly why, but from participating in this forum, I would Upgrade firmware and always follow that with an IMU calibration and gimbal calibration. You will get some other chaps chiming in here.

Yea I figured out the heat thing pretty quick lol, I've never seen my iPad overheat before. That was interesting.

 

[m00n.patrol]

Also, do not recalibrate the IMU in 100° heat! Your warm up times will go from 15 seconds to minutes on every flight thereafter! Put your bird with battery removed in front of an AC unit for 15-20 minutes, along with the battery next to it, to get them both as cold as possible, while setting up the app with the transmitter on the calibrate IMU screen, with a previously perfectly levelled surface away from all metal ready to use for the calibration. Then, put the cold battery inside the cold bird and immediately power up the battery, and do the IMU calibration. Mine went from 5 minute warmup times to 15 second warmup times by following this procedure!

Yea so this is exactly why I haven't done it yet. I opted to pack it up and head home instead. I have read about the getting it cold thing. So this is not myth? Seems insane practice for a commercial hardware/software package. I guess that's exactly what I'll do...

 

[m00n.patrol]

So all is cooled, turned it back on and sure enough no IMU error. Can someone provide more info on what/why this happens without calibration? I'm more just curious now.

 

[bobmyers]

So all is cooled, turned it back on and sure enough no IMU error. Can someone provide more info on what/why this happens without calibration? I'm more just curious now.

No idea here-- but go ahead and calibrate IMU and gimbal anyway--

 

[GadgetGuy]

No idea here-- but go ahead and calibrate IMU and gimbal anyway--

...with the aircraft and the battery as cold as you can get them before the IMU. DJI does them in the factory in a very cold, refrigerated room, on a perfectly leveled metal-free surface!