Re: GPS assist and Heli
« Reply #90 on: January 11, 2018, 02:08:36 am »
As far as I know, the accel cal has never used a home location, but your point that it could use one for best accuracy is true...

I think this is because CC3D and Basic don't need it (no home location) and INS13 allows calibration with home location values farther up the stack and that could take it into account.

It does matter what orientation the board has.  That is what it asks you for.  If you do it with it still mounted in the vehicle, just hold the vehicle so the board is in the desired orientation.

I would not rip it out just to put in in the freezer.  Most people just do it from cool room temperature to full warm temperature.  a 10C difference is all that is required IIRC.  If above the equator, maybe just put it outside in the winter for a few minutes...


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Re: GPS assist and Heli
« Reply #91 on: January 11, 2018, 03:49:10 am »
It would save me a lot of trouble and time if I can leave it mounted inside heli while doing these calibrations (thermo and accelerometer).
Its minus 5 C outside today so I will try that.
Also will try just keep the virtual orientation setting but placing the board in the positions GCS asks me.

In the previous accelerometer calibration i have been flying with, I did it with the virtual orientation set, but placing the whole heli in the positions GCS asked me.
This should make a difference... maybe this is one reason why Attitude is confused...

Re: GPS assist and Heli
« Reply #92 on: January 11, 2018, 04:59:54 am »
for accel calibration:
Make sure the board orientation is as requested, as exactly as possible and as motionless as possible.

Heli landing gear on floor, on wall (joint with floor for completely locked in orientation), ceiling upside down...  The motionless part is probably the hardest issue.  Good luck.

for thermal calibration:
The main issue is that it needs to be completely motionless for the whole time.  Afterward, you may want to look at gyro scope and notice there is a slight bias now.  The gyro noise is not centered exactly on zero.  To fix this, just make sure to run the gyro calibration again, after the thermal calibration.  The scope will show you that it is fixed now.
« Last Edit: January 11, 2018, 05:31:09 am by TheOtherCliff »


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Re: GPS assist and Heli
« Reply #93 on: January 12, 2018, 09:12:57 am »
Ah thats a great idea to do floor, wall, ceiling for support.
I might need to redo it later, but I think I got the thermo calibration okay.
It was tied down heavily and I applied a hair dryer gently blowing hot air over the frame.
It said the range was some 60 degrees range from 3-4 C up to over 60.
I am still waiting for the delivery of my main shaft before I can do any flying.