"Save Trim" issue (board orientation in cause?)

Hello guys,

Please excuse me if I do something wrong by posting this, but I am not used to forums since a long time, so I would probably miss some stuff…

Anyway, The problem is that I don’t know if I’m doing everything wrong or if I found some bug in the “Save Trim” function.

Here is the thing I’ve done to use the “Save Trim” function :
[ul][li]I set the correct button (Thr Cut in my case) to the channel 7 “Save Trim” function in the APM Planner.[/li]
[li]Then put every trim to it’s default position and ensure channel 7 is off.[/li]
[li]Arm the beast.[/li]
[li]Take off (in “stabilise” mode) and hover while setting the trims.[/li]
[li]Once the trims were correctly set, I just landed and disarmed it.[/li]
[li]Then turned the “Save Trim” switch on for something like 3 seconds, then off.[/li][/ul]
That’s all for the procedure. (I hope it’s the correct way to do it)

Here comes the issue :
After that procedure done, I took all trims back to their default position, rearmed the quad, tried to take off, and guess what happened…
The quad left the ground by drifting the same way but even stronger.
After some tests, I’m asking myself : Could it be the orientation of the apm ?
Because I oriented mine upside down in a 180° roll, and noticed that the problem does seem to occur only for the roll axis.
So, I think that it could be possible that the"Save Trim" function doesn’t care of the orientation parameter of the APM, and that’s why it seem to strengthen the roll instead of getting rid of it.
And if I’m right, maybe this bug is also causing trouble in other function (like “AutoTrim” or “Autotune”).
I didn’t mention that if I just keep the trims on the controller without saving them to the apm, everything works fine, so I don’t think I missed something in the configuration.

Except this little issue making me crazy, I just want to thank you all for that work, the thing you made is just incredible and also open-source. I love that, and perhaps, if I have enough interesting ideas to improve this project, I will begin to help you make it go further, I’m not bad at coding and electronics (at least better than in English) so please guys, wait for me :wink:.

Nailed it !

After many checks, it appears that when I save the trims by switching ON/OFF, the roll trim is saved as the pitch trim value and the pitch trim is also replaced by the roll trim value.
I see this happening clearly in the APM flight display, when I save some roll to the left for example it lift the quad’s nose and the forward trim gives roll to the left.
OK, according to that, I checked if something was going wrong with my radio (Turnigy 9x) on the RC calibration screen and each trim is at the right place there.
So, I was obviously wrong the first time by telling it only happens on the roll axis. In fact, in my case, for a reason or another, it reverses the trims during saving.
I didn’t notice any other problem related to reversed sticks or trims during flight in “Stabilize Mode”, so manually it would work fine.
But alike I’d love to optimize this quad and then directly begin to work on it as a dev platform for adding/testing new features, I just can’t be stopped by something like that, it needs to be fully operational for me to begin to work on it.

So, not afraid of coding, I took a look on the code, and found everything about the “Save Trim” switch in the APM code, but pretty new to this project, I don’t know the program enough yet to emit a diagnostic, so simply I won’t.

Anyway, I’ll take every advice or idea from anyone, and like I said in the first post, I could also have missed or done something wrong in the conf or with the radio, I don’t think so only by reading the reactions in the Flight display, and alike it’s not an issue in flight but in -Standby mode- (don’t know how you call that), I didn’t check any flight logs, so I also could be completely wrong.

I’ll continue to check it on my own for the moment, but if any idea related to this issue comes to you, please, write it down, I’d be so glad to use this quad at 100% before tuning it at 200% haha.

Thanks again guys.