MobiFlight Community Support

Hi,
I'm building a servo driven turn co-ordinator but having trouble with calibrating the ball movement, I'm using FSUIPC offset 036E 1 bit, monitoring this offset in FSUIPC shows the correct value -/+127 full left and right or 0 for center. However monitoring the same offset in Mobiflight in the FSUIPC window full left shows a value of 140, full right 120 and center 255 Does anyone have any idea whats going on here ? iam I using the correct offset ? does any else have this problem ?

any help would eb much appreciated !

Hi crazypilot_uk,

this seems to be a signed / unsigned problem again.

With sign (signed) the value goes from -128 to + 127 with 0 in the middle. Without sign, he should then go in the range +127 - +255 - +127. Will be a bug.

Is there a way to recognize the right / left?

You could enter in the Transform line: $ -255, then the middle position would be 0 and the left stop -127, the right but unfortunately also

What happens to you at the offset 0x037C? Are there on the MF side the right values? Then you could take this value and put in the Transform line: $ / 4 and have your result.

Hi StephanHo,
Mobiflight handles offset 037C fine, plus and minus values seem to be ok however I cant use this offset for the turn co-ordinator ball as it doesnt follow correctly whats happing in the aircraft, I'm currently using 037c for the bank of the turn co-ordinator which is working fine.

Any other ideas how to use 036E offset ?

Brgds.

Hi guys....

Right idea.... Wrong solution
For a Signed Unsigned Problem you need a IF ELSE function to solve.... not a single transform cause the "upper half" of the offset is already correct !
A transform like "$-255" as Stephan said only change the problematic side to the other but not solve the issue !

Try the follow two things.

1. To get a value like original -127 to +127 .....
Use transform : if($>127,$-255,$)
PROBLEM : Maby you work with a servo.... And Servos can have problems with negative values.... So your current range from -127 to +127 will not work perfect... YOU must try out.

2. to get a Value with only possible numbers..... 0-255 ( with 128 = Center)
Use transform : if($>127,$-128,$+128)
Now Max Left = 0 ... Center = 128 Max Right = 255
(Thats maby better for servo setting)

Have Fun !

Hey guys
I got stuck with this as well so I would very much appreciate your help.
I'm working around the clock to convert my new PA23 250 cockpit section. I stripped the whole panel and managed to get nearly all of the basic sixpack instruments fitted with servos and successfully working with Xplane.
I have to say again, I JUST LOVE MOBIFLIGHT !!
It's an amazing tool so I'll surely and continuously support it's development as much as I can.

Now regarding my issue. The turn coordinator Ball (offset 036E) seems to feed mobiflight with very confusing data.
For some reason, instead of negative and positive values, the FSUIPC Value goes up 0 - 255 for one direction and down 255 - 0 for another direction.
This really doesn't make any sense. I can't think of any formula that could be used for the transform function here as we are going through the same numbers but in different directions.

Thanks in advance
Jay

As i said Multiple Times .... Xplane can be problematic.
We can just think about FSUIPC Logics ( Myself, Stephan and as i know also Sebastian not work with Xplane)
So we must trust in XPUIPC to do the same as FSUIPC . If not we can not figure out ourself.

About Problem:

Do you still use a Transform ??

What you report ( Value go 0-256 in one direction and sameway backwards in other is normlay not possible,)

Without transform it should be something like this.....
In Center Position value should be 0 Zero.
If Ball goes to the right value increase to 127 (Maximum Right)
If ball goes back value should decrase from 127 back to Zero.
If Ball goes to the left Value jump to 255 and decrease to 128 (Maximum LEFT)
If Ball goes back it increase from 128 to 255 and swap to 0 when reaching the Center Position

Whatever.... Value can NOT reach 255 in both directions.... Only to the rigth ! (Aslong no transgform is in use. )


Solution:
If my idea is correct then Awnser is the same like above in other request ....

For -128 to +127 Value use if($>127,$-255,$)
For 0-255 range use if($>127,$-128,$+128)

If i´m wrong and XPUIPC is realy different here then you must find a logic here. Maby check Offset 0380

Offser: 0380 .... Size 4 Byte .... Typ: FLOAT32 ..... turn coordinator ball position, –1.0 to +1.0

NOTE: This is a floating Value.... Here a Miltiply is needed to get full numbers we can use for a motor.

The answer from pizman is correct

Either use: if($>127,$-255,$) in the transform field or use the comparison tab and say

if current value > 127 then $-255 else $