Self accelerating motors on Revo
« on: January 09, 2016, 10:59:22 pm »
Hello
I am trying to set up a HK Bee quad with one of the BG Revo boards.
All good but on any stabilized mode (like Attitude) the motors slowly increase their revs from neutral to worrying even if the quad is not moving.
It is related to Baro (should bot be used in atii mode, right) or maybe to the gyros / vibrations?
The gyros seems to oscillate between -50 to +30 while the accelerometer is oscillating between -12 to +6 (all Scope readings)
I didn't had the chance to fly it yet but it's a bit worrying.
The board is mounted on one of those boards with silicone feet between them that comes with the cc3d atom
Please advise, you know way more than me (I'm more a fixed wing pilot but I have played before with Naze32+ Cleanflight).

regards
Paul

f5soh

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Re: Self accelerating motors on Revo
« Reply #1 on: January 09, 2016, 11:12:41 pm »
Hi Paul, welcome here.

Motor rpm changes looks a normal behavior, the small error (from gyros or acc/attitude angle) is accumulated with "I" term from PID controller. Try setting all "I" terms to zero in stabilization tab for testing purposes.

Laurent

Re: Self accelerating motors on Revo
« Reply #2 on: January 10, 2016, 02:27:31 am »
Fly it.  :)  This is an issue that only happens on the ground because the controller is trying to adjust the level by increasing a motor, but it doesn't help because the motor doesn't have enough thrust to actually lift that corner off the ground.

Beware:  Don't let it do this speedup a long time and then try to lift off.  It tries harder and harder to make it level, so that motor is running a lot faster.  When you lift off, it will try to flip over because that motor is too fast.

When you get ready for your first flight, Arm and quickly increase throttle until it is hovering at about knee high to chest high.  If you are worried about it being set up correctly (I guess you should be :) ), and are willing to accept the risk, get out your old winter coat and put it on for arm protection, then carefully hover while holding it with your hand.  It should fight you to stay level.  A little bit of roll/pitch on the transmitter (careful not to steer it into your arm) should change the bank angle.  Note that yaw (rudder) is very weak and you will either have to rotate it by hand so that all motors are about the same, or loosen you grip enough that you can feel it moving in the desired direction.  The desired direction is the direction it was pointing when the motors were started.
« Last Edit: January 10, 2016, 02:41:33 am by TheOtherCliff »

Re: Self accelerating motors on Revo
« Reply #3 on: January 13, 2016, 12:54:03 pm »
Many thanks for your input guys, i'll give it a try as soon as our British weather let me do it...

Re: Self accelerating motors on Revo
« Reply #4 on: January 20, 2016, 02:03:45 pm »
Hello
Following in this thread (I don't want to open another), I bought an GPS+ external mag unit like this:
http://www.ebay.co.uk/itm/252223953561?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I know that the GPS has to be connected to the main port (4 wires) how about the mag (2 wires) where Do I connect them?
Also do I need to enable something in the settings in order to use it? And the current firmware support the external mag?

Please advise?
Ty, Paul

Re: Self accelerating motors on Revo
« Reply #5 on: February 04, 2016, 10:23:14 am »
Hello
Following in this thread (I don't want to open another), I bought an GPS+ external mag unit like this:
http://www.ebay.co.uk/itm/252223953561?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I know that the GPS has to be connected to the main port (4 wires) how about the mag (2 wires) where Do I connect them?
Also do I need to enable something in the settings in order to use it? And the current firmware support the external mag?

Please advise?
Ty, Paul

Hi All!
I have exactly the same situation. The second two wires connector should go into flexi port, but external MAG does not seem to be working. What connection type/speed should I set for flexi port port to make external mag work correctly? If nothing is set, system health panel indicates that MAG is not present in my configuration (black).
Thanks in advance!
-K.

hwh

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Re: Self accelerating motors on Revo
« Reply #6 on: February 04, 2016, 03:00:05 pm »
It's available in the next release, 16.01.   Wiring and configuration is https://librepilot.atlassian.net/wiki/display/LPDOC/GPS+setup

Re: Self accelerating motors on Revo
« Reply #7 on: February 05, 2016, 07:09:24 pm »
It's available in the next release, 16.01.   Wiring and configuration is https://librepilot.atlassian.net/wiki/display/LPDOC/GPS+setup
Thanks for the answer! I have managed to do wiring, and also managed to make mag working. I guess there is a drop of info missing on the wiki: Two wires cable should go to flexi port that is configured as I2C.