Question about FrSky output mapping

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jjuk
Posts: 305
Joined: Thu 05. Oct 2017 20:06:35

This is a digital protocol. Are the centre frequently and endpoints not defined in the receiver specification as a known constant values?
ZeXx86
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They are not defined, actually each manufacturer have these values different. And some radios allow to change these centers.

But it would be enough if the radio manufacturers would define absolute values for min, max and center. But they still insist on analogue value conversion from PWM signal.
Other problem is that even temperature is changing readings. So different day center can be at a very different position.
Other channels are not critical for steering and are not usually affected by drifts like these that are controlled by sticks, so calibration is not applied there.
Spirit System developer
azaz44
Posts: 288
Joined: Thu 12. Jul 2018 17:51:47

Mattes61 wrote:Hello azaz44,
you are right, the other channels except RUD, ELE and AIL don't center automatically, thats also my realization -
The best idea would be to center all channels automatically then that would be logical and consistent -

Why is this not implemented, what is the reason ?
I think this is not even possible. Spirit calibrates it at power on, and RUD, AIL and ELE are at zero at this time. Other channels are not.
Mattes61
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As I understand Tomas, the zero points are probably calculated from the existing min and max values, not via the real zero position, so it doesn't matter what the middle frequency is in the end -

Regards
azaz44
Posts: 288
Joined: Thu 12. Jul 2018 17:51:47

Mattes61 wrote:As I understand Tomas, the zero points are probably calculated from the existing min and max values, not via the real zero position, so it doesn't matter what the middle frequency is in the end -
I don't think they are calculated from min or max. Spirit looks what are values of RUD, AIL and ELE when it's powered on, and assumes these are zeros. Your sticks are better centered at this point. And it also estimates PITCH center from this.

I think main reason for doing this is to account for gimbals with potentiometers, where this center value can change a bit over time. Hall sensors are much better and maybe wouldn't need this calibration, but not every radio has them.
franz88
Posts: 338
Joined: Sun 08. Jan 2023 14:32:43

tomas wouldn't it be better leave in the wizard the list central impulse servo but in the advanced add an editable field where to write for the central impulse 1518 or 1520 or whatever value we want.
So we have centering for each type of radio.
it's a idea
ZeXx86
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I am afraid we dont want to make things complicated.
It worked in the way as it is now without any problem for over 12 years.
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Mattes61
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Tomas would it be possible that you explain how auto center will work ?
Thanks !
jasc
Posts: 61
Joined: Fri 20. Aug 2021 6:12:26

I dont get it, why this is such a big thing
just adjust outputs so Spirit sees +/- 100 and call it a day ....
Mattes61
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Joined: Wed 21. Dec 2016 15:13:38
Location: Germany

jasc wrote:I dont get it, why this is such a big thing
just adjust outputs so Spirit sees +/- 100 and call it a day ....
Thanks for your great input...forget it!
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