MobiFlight Community Support

HI every body
i have servo motor tower pro micro sg 90 using 737 ngx with p3d v4 & arduino mega
but my Problem is servo not run on my gague correctly example: the EGT gague start from 0 to 8 & turn back to 4 when i start APU in pmdg ngx but
my servo start from 8 to 2 & turn back to 4 I think the problem is value interpolation or comparison value i tried many values but no sucsess & this is setting ihave

fsuipc : offset is 0x648C
value type :float
size in byte :4
compare :no settings because i dont know the correct values for EGT gague input -output & this is my main Problem
display :min value :0
max value :1000
max rotation :100%
& ihave another question
how i can calculate interpolation values for other gagues like duct press. Diff press ..cabin climb ..fuel temp for home made overhead
with steep motor or servo motor...
i hope any body to help me with EGT gague
sorry for bad Einglish

best regards 4 all
Abdo....

Hi
Welcome to Mobiflight !

At first.... You not need to /PUSH a Posting after 10 Hrs... Specialy not when you request it middle in the night !
We normaly reply within 24 hrs to every question !

*****

About your Problem.....

This can not be awnserd directly.... I not see your Gauge... So i not know what you need.

Some Basic rules:

1. Is the Needed Range Possible with your hardware ?
A standard Servo have a range of 180° .... If you need more moving (for example like 270°) then it can´t work. here you need a servo with more range or a selfmade cogwheel system.
If you need a gauge that can turn multiple times ( like altimeter) then a stepper is needed.... Whatever myself i use 100% steppers.... I Think they are more accurate like servus.... but this a personal taste !

2. Is the Gauge LINEAR or NON-LINEAR ??
A Linear gauge ( i think for example APU EGT is linear) can be used without a interpolation.... A NON LINEAR Gauge like the Flaps in B737 MUST be used with interpolation !

3. In What direction does it run ? Clockwise or Counterclockwise ?
If your setup is wrong (inverted) then you can also use a cogwheel to reverse it OR you must use Interpolation, too to make this posible.

4. What is the Range of the Raw FSUIPC Value ???
You need to understand the System of the Value to find the correct settings for the Motor Setup Data ( Rotation ,Min Value, max Value).
Also you need it to calculate for example the needed interpolation Data.

*****

In your situation....

Please find out how the FSUIPC Value is working.... Where it starts ? Whats the value for example if needle should be at position 4 ?
Is it 4000 is it 4 or something else ?

Please give me that data ( i have no installed PMDG at the moment to test this myself) .... then i can give you the needed settings !

hi pizman my servo is 180
i think my Problem solved 95%
I used values in interpolation
0=1000
1000=0
but the gague start from 1 to 8 & back to 4
i want the gague start from 0 to 8 & back to 4
in test mode start from 0 to 8 normaly
waiting for any body have pmdg 737 ngx
thnx 4 your help & fast replay
regards
Abdo

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
UPDATE : I changed the servo by 28BYJ-48 Uln2003 stepper motor & the gague worked perfectly as expected
and this is my settings if any body search about it
APU EGT

offset: 0x648C
value type: float
size in bytes: 4
mask value: 0xFFFFFFFF
sim/stepper: 1600 / 4096
test value: 1000
transform :$*0.582
compare : no settings
best regards 4 all

Nice to hear it workes....

But maby you think to difficult.....
For future problems you should think much easyer....

Not try to compare the value..... Make better inputs in the Display/ Motor Settings Tab.....

to Limit the Range of the Display ( For examplethe EGT gauge only use maby 270° of the full circle..... 4096 Steps is a circle.... so Use just 3072 Thats the same like 75% of the Circle.
To set the Value Range you must change the SIM Value.... If your offset can have for example a value form 0-1000 (0 is Zero Point.... 1000 is the maximum point)
then say SIM 1000 Stepper 3072.
Now gauge only turn 270° Zero is lower position.... and 1000 means a turn to the 270° Point !

As i said.... To understand this ( and to set the interpolations for advanced displays in the future) you MUST explore the Offset itself.... Try out all Posible Positions in the Sim and check whats the Offset Values in that situations.....then you understand the mathematical logic and you can figure out a setting that work for you !

Have Fun !