ERSKY9X Coding

[MikeB]

I've been looking at the operation of the trims. Currently, these are used as offsets from the centre position, with the stick input added on. This means that if, for example, you have +10% on a trim, then stick movement in that direction will reach the limit (100%) when the stick has only moved 90%, the last 10% of stick movement has no effect. If you move the stick in the opposite direction, then when the stick is at -100%, the channel output is only at -90%.
This is different from the operation of the sub-trim (offset in the limits menu), where the stick movement is scaled to reach +/-100% from the offset position.
I plan on adding an option where you may either use the trims as they currently operate, or have the stick movement scaled so you do reach +/-100% from the trim position. If you have a rate setting on the stick, this will scale appropriately.

Mike.

[jhsa]

Mike, I think I like your idea.. Dead band is not good as well as losing servo movement.
The only "downside" I see is that we lose a bit of linearity? Something like adding a higher rate due to the compression? Or am I misunderstanding it?
Also this would be more evident with larger amounts of trim AND Sub-Trim, at the same time..
But there will always be a compromise, right?
If this works well, I believe there is no need for an option to select between this way or the old way. Just change it, it is an improvement, no more dead band or lost throw..

João

[Kilrah]

What will you use as "reference" for the now fixed trim end points?

I've never seen a radio doing it that way, IMO the hard to understand implications of a "non-linear" mode there are much more likely to bite people.

When setting things up "properly" (with <100% D/Rs) the margin for trim not to clip stick throw is naturally there.

[jhsa]

When setting things up "properly" (with <100% D/Rs) the margin for trim not to clip stick throw is naturally there.

Yes, but you are still reducing throw on one of the sides of the travel to match the other side..
That is the way I normally do it by the way..

João

[Kilrah]

No, you precisely still have the same amount of travel on either side of the new center!

If you had it non linear OK you'd have more absolute throw on one side, but then your plane responds faster to a stick order on one side than to the other (by 2x the trim excursion), can't see why you'd want that unless your goal is just to have as much throw as possible without any consideration for precision...

[jhsa]

No, you precisely still have the same amount of travel on either side of the new center!

Yes you have, but what i said is that you will not have the same amount of throw as you had before. You lose the amount of throw that equals the amount of trim used. And anyway, that is not the trim you/we are talking about now.. It's the sub-trim. Mike is talking about the "Trim" itself. You don't normally change the trim and compensate with D/R

If you had it non linear OK you'd have more absolute throw on one side, but then your plane responds faster to a stick order on one side than to the other (by 2x the trim excursion), can't see why you'd want that unless your goal is just to have as much throw as possible without any consideration for precision...

That is that compromise I was talking about. I think I'd prefer that instead of reduced throw in one side, or dead band on the other

João

[Kilrah]

Yes you have, but what i said is that you will not have the same amount of throw as you had before. You lose the amount of throw that equals the amount of trim used.

Well we might not be talking of the same thing... if you trim right you lose some left throw with regard to the old center point, but you keep the same throw with regard to the new center, which is what matters. The throw with regard to the old center doesn't matter, as that center was wrong anyway (or you wouldn't have needed to trim).

I.e. how it is now is what keeps the model response the same regardless of trim position. A non linear option would cause response to change with trim position.

And anyway, that is not the trim you/we are talking about now.. It's the sub-trim.

Uh no, I'm definitely talking about the trim.

[jhsa]

Well we might not be talking of the same thing... if you trim right you lose some left throw with regard to the old center point, but you keep the same throw with regard to the new center, which is what matters. The throw with regard to the old center doesn't matter, as that center was wrong anyway (or you wouldn't have needed to trim).

You introduce dead band on the right side then, so you won't have the same throw as the other side, unless you enable extended limits.
If you use the D/R to compensate, you will lose servo throw. Just tried it in eepskye..
Mike's idea would solve that problem. As I also said before, that also brings other situations.

I.e. how it is now is what keeps the model response the same regardless of trim position. A non linear option would cause response to change with trim position.

That is what I also said above..

Uh no, I'm definitely talking about the trim.

Sorry, it doesn't sound like it.. You just don't compensate normal trim with Dual rates You do that to compensate for sub-trim when setting up a model. I use the Dual rate menu to match two independent elevator halves, or 2 flaps, for example.. And normally a curve to overcome some non linearity due to different linkages, or different servo centering, so they move exactly the same..


Mike, what about something like the "Auto Limits" for the trims? That would avoid the linearity problem, as it would correct it automatically as with the Sub-Trims.


João

[MikeB]

Scaling down on the side the trim goes isn't bad, it avoids a deadband, but perhaps scaling up on the other side is not needed.
Note, this would likely remain as an option, so you don't have to use it.

Mike.

[jhsa]

would that be a radio setting or a model setting?

Thanks

João

[jhsa]

Scaling down on the side the trim goes isn't bad, it avoids a deadband, but perhaps scaling up on the other side is not needed.


Mike.

I'm not sure Mike, I do use the auto limits all the time.. I normally use lots of servo throw on my models (acro), and I don't really like the idea of losing it when I trim..

João

[MikeB]

It's a model setting.
You don't!
Assume trim centre and limits at +/-100%. The stick currently will move the servo from -100% to +100%. Now put in +20% trim, currently the stick will move you from +20% to -80% (so 100% movement), but the other way the first 80% of the stick moves you from +20% to +100% and the last 20% of stick movement does nothing.
My present suggestion is for an option that does the same, except the stick movement from the +20% trim is scaled so the whole stick movement is needed to get to +100%.
If you have some sub-trim, and auto-limits, these are applied later, and work as before.
If you prefer, you don't use the option, but set the mix weight to 80%, then full trim+full stick only reach to +100%, so no deadband.

Mike.

[jhsa]

The way I see it I do lose throw. Please see..

Now put in +20% trim, currently the stick will move you from +20% to -80% (so 100% movement),

Exactly, that's 100% movement.

but the other way the first 80% of the stick moves you from +20% to +100%

~

And this side moves from 20 to 100, that is, on this side I have only 80% travel. To have the same travel as the other side, I need to turn E.Limits ON and set the limit to 120%.

That means,if model was perfectly setup with the trims at center, and for full defection of the control surface, it will respond equally to both sides of the travel. With 20% trim, at full defection of the same surface, it will not respond equally on both sides. The reason is, with with 20% of trim, the plane will fly straight with the control surface offset. You will also need 20% more deflection of the control surface on the same direction of the offset to make it react the same way as if it had zero trim. If you give only 80%, it won't react the same.
The angle of the control surface movement should be the same on both sides of the servo travel.
To achieve that, I use the DR menu because I can adjust both sides independently, or enable E.Limits, or both, depending on the situation..

João

[Kilrah]

And this side moves from 20 to 100, that is, on this side I have only 80% travel. To have the same travel as the other side, I need to turn E.Limits ON and set the limit to 120%.

But you can't do that, becasue you already had (or should have had) your limits set for the max travel that is mechanically possible - increasing them would just cause your linkage to bind.

Really what he's talking of implementing won't change any of your throws, it will only eliminate stick deadband by reducing stick sensitivity (and thus making it different on both sides of the stick, which is why its usefulness is very questionable as I can't think of anyone who would like his aircraft to behave differently in one direction than another, and for it to change everytime he trims).

Just like you showed when saying we were talking of subtrim, you're mixing what happens (and should be configured) on the input/control side and what happens on the output / servo side.

[MikeB]

If you put in some sub-trim, and don't change any other settings, then you effectively get a different sensitivity on the two sides of the stick already. If you have (say) 10% sub-trim in, then one side of the stick movement gives 90% movement while the other side gives 110%.
If you have zero sub-trim, then put in some ordinary trim, then use the instant trim function, you get a change in sensitivity and deadband at that point because trim and sub-trim are handled differently. As always, if you need some trim or sub-trim, you probably need to adjust the mechanical linkage so they are both zero, in which case these settings are not needed at all!

Mike.

[jhsa]

Kilrah, your aircraft will only behave differently because of what I said above.. You do not have the same throw on both sides. Forget the limits for a moment, for 20% trim you have 80% on one side and 100% on the other. That is NOT the same amount of travel as if the model didn't need any trimming. There are two things you can do.

1. Adjust the limits carefully to give more 20% on one side without breaking stuff. But this should only be used when you've already copied the trims to the sub-trim as the trim might not be always equal for different speeds or even different days with different weather conditions or even different air density. It's just like in real aircraft..
Of course the limits have to be changed, but this is when setting the model up, not when normally trimming the model in flight. And that is what I do. I set the limits to the max the mechanical limits allow. That is why they are called limits.

2. Adjust the mixer and/or DR. Sometimes only mix and differential are enough, but you will lose throw if you bring the travel of the side that has 100%, down to 80%, to match the other side. But again, this is when setting up the model. The subject here is "Trims", and trimming is NOT a fixed setting It changes all the time.

João

[jhsa]

. As always, if you need some trim or sub-trim, you probably need to adjust the mechanical linkage so they are both zero, in which case these settings are not needed at all!

Mike.

Exactly, and if you zero the trim by offsetting the linkage, you will have the same throw on both sides, like it should be. That is what I have been saying on all my posts.. And I believe that is what the radio should also do for the cases where adjusting linkage is not possible.

João
EDIT: again all this talking is only valid is extreme cases where a model needs always huge amount of trimming. Then the trims should be copied to the subtrims, or even better adjust linkages.
I'm talking about huge amounts of TRIM in flight when for example you lower the flaps or landing gear and the trim changes considerably. Here,nI think the trims shoukd keepbthe same throw on both sides, and without dead band.

[Kilrah]

Kilrah, your aircraft will only behave differently because of what I said above.. You do not have the same throw on both sides. Forget the limits for a moment, for 20% trim you have 80% on one side and 100% on the other.

Only in some cases, where your model is set up "wrong" and you didn't leave margin for the trim to operate!

[jhsa]

Some aircraft (and not only models) have great trim variations, depending on some configurations. Landing gear out, for example can add a great amount of drag and require a considerable amount of trim. That doesn't mean the model is setup wrong.

João

[MikeB]

I've just posted a test version of ersky9x. This has a new method of editing the entries for the custom telemetry displays.
The editing still works as it did before, but if you press MENU LONG, you get a new display where the possible values are displayed in a grid of 6 rows by 4 columns. This makes it easier to see what values are available, and where they are. Simply navigate to the required value, then press MENU to accept it or EXIT to cancel and leave the value unchanged.
As a help to see what the values represent, copy the file from the .zip called Helptel.txt into the root of the SD card (you may edit this file to add more info or change the language).
The bottom line of this new display will show the text from the file for the highlighted item after a short time.

This type of editing may well become available for other items in due course.

Happy new year!

Mike.

[jhsa]

Mike, what is "ersky9xs_rom.bin"?? Is this for the skyboard only?
If so, does that mean "ersky9x_rom.bin" is only for the Ar9x board??
Thanks and Happy New Year..

Happy New Year to all

João

[MikeB]

That will be the case as the SKY board only has 256K flash and we are getting close to that limit, all the other ARM boards have 512K flash. At the moment "ersky9x_rom.bin" still fits on the SKY board.

Mike.

[jhsa]

Thanks Mike. I flashed my 9XT last night when I came back from work. It looked very nice but didn't really have time to test or have a good look. I can say it does look very good and "promising"
If proved to be a good and easy way of editing, and I believe it will be, It could be made the only way of selecting sources? I mean just press menu (not long) to enter this list?

Thank you for trying to make ersky9x even easier to work with. I believe that is very important. And the way you have been implementing it, it keeps the same power at worst. Most of the times you made ersky9x or er9x more user friendly, they actually became more powerful than before. Examples are the new menu system, voice menu, etc..

João

[jhsa]

As a help to see what the values represent, copy the file from the .zip called Helptel.txt into the root of the SD card (you may edit this file to add more info or change the language).
The bottom line of this new display will show the text from the file for the highlighted item after a short time.

Mike, I think this is not working as it should, at least not on the 9XT (will flash the other next).
At the bottom, I see the same as the "Source" name. A1, A2, TmOK, etc. No extra text at all.

Apart from that, I gotta say I like it very much, thank you. If only would be possible to re-order the sources, like for example putting A1, A2, A3, and A4 all together, it would be nice.. But I guess if it was that simple, you would have already done it..

João

EDIT: The same on my Ar9x radio. The last line displays the source name.. No extra text. I have placed the "Helptel.txt" file in the rood directory of the SD Card.

[MikeB]

All working OK for me on 9XT, SKT, 'PRO, AR9X, Taranis.
Double check the "Helptel.txt" file is in the root, has exactly that spelling (Capital H) and starts like:

Code: Select all

Cvlt,Lowest Cell
Amps,Current
Mah ,Capacity used
Ctot,Cells Total

Mike.

[jhsa]

Mike, I copied the file from the zip file to the sd card root directory. And it does not work..

[MikeB]

OK, I'm not forceing looking in the root. If you have some music set, it's changing the current directory, then looking there.

Mike.

[KAL]

Hi guys,

I checked the new menu on two 9XR-PROs and three 9Xtremes and all works well.
Very nice

And a Happy New Year to you all

Klaus

[jhsa]

OK, I'm not forceing looking in the root. If you have some music set, it's changing the current directory, then looking there.

Mike.

Thanks Mike, can you fix that, or shall I do something else?

João

[MikeB]

Fixed, new test version posted.
The Model setup|Music menu includes a "Configure" option that takes you to the Music setup menu.
The display of TSSI/Tx=/Swr should be fixed.
The buffer for the text storage of the Multi.txt file has been increased,it was not large enough for the latest file.

Mike.