How to export the trimmer position?

[Battlemage]

Hi everyone,

 

currently I'm working on the trim and autopilot functions of my DIY FFB joystick.

 

For my FFB solution I'm not using a real FFB device. Instead I installed "vJoy" to let DCS think that a FFB device is connected.

I wrote a tool that can readout the Export.log informations and also controls the motors of the joystick axis.

With this setup I'll need to generate the FFB effects depending on the informations I get from the export file.

 

If I check the trim and autopilot functions on the "ControlsIndicator" overlay, I see that the trim indicator is moving while the stick position doesn't

change. Which is correct, because my FFB joystick has no information yet that it should move the axis to adapt the change of the trimmer position.

 

 

So what I need now is something to get the data from the trim position into the export file.

 

 

I'm not sure if this is a module specific thing, but as the F-14 is my main ride I checked the \F14\Cockpit\draw_args.lua

for the arguments but had no luck.

 

I also had a look at the \F14\Cockpit\Scripts\ControlsIndicator\ControlsIndicator_page.lua.

 

There I found this:

trimmer_stick_position = CreateElement "ceTexPoly"

trimmer_stick_position.name = "trimmer_stick_position"

This is the correct indicator, but I have no Idea how to export the position...

 

 

I would be thankful for any advise.

[harryharry]

Hi, I think I had the same problem a week ago:

 

https://forums.eagle.ru/showthread.php?t=172964&page=43

 

Harry

[Battlemage]

Thank you Harry for your reply.

 

I already read this before as I searched the forum for a solution.

But I dont know how to use this to get the information that I need. The TF51 has trim wheels which makes it possible to get their data with "get_argument_value()".

However, in the F-14 the trim and autopilot system changes the neutral position of the stick itself.

So I think there are no instruments or controls that could be read out with "get_argument_value()".

At least I found none in the \F14\Cockpit\draw_args.lua.

[CeeGee]

Battlemage,

 

I believe you mean the neutral position of the "artificial control feel" of the f-14 stick.

The neutral position of the control surface (Elevons) and therefore the stick in the F-14 does not change. This is indicated by the 0 on the Control Surface Position Indicator.

 

Furthermore I'm very interested on how you would like to use the control/trim indicator position as data for your FFB stick and how are you solving the actual forces on the stick?

Are you going to solve this mechanically (springs) or electrically (Servo's/DC motors) or a combination of the two?

 

Greetz,

 

CeeGee

[Battlemage]

Hi CeeGee,

 

maybe we mean the same, but I read in different posts in the Heatblur forum that the trim system changes the neutral position of the stick.

 

https://forums.eagle.ru/showthread.php?t=275549

 

... The special option essentially makes it so that the trim actuator functions like real life (moving the neutral position of the stick). ...

 

 

For your question: I use servo motors in "position control mode". In this mode the motor tries to hold its position (in this case the neutral position of the stick).

As you pull the stick you have to work against the motor. As you relase the stick the motor moves back to its old position.

The force that the motor uses can be changed by parameter. I also can change the "neutral" position of the motors.

 

I wrote a software-tool that reads the data from the export.lua and also controls the motors (neutral position and force).

If I could get the trim offset from the export.lua I could use this values to change the neutral positions of the motors depending on this values.

 

 

But for now I'm going with plan-b. I realized the trim function completly outside of DCS. I use the joystick trim buttons directly

in my software. And this is working fine so far.

 

I plan to share more infos. Maybe in my own homepit thread.

Unfortunately I have almost zero time to work on this project thees days.

Edited July 17, 2020 by Battlemage

[erniedaoage]

Just a heads up, if you trim with your software you have to make sure every time you start the aircraft your stick has to be in the same position as the virtual stick. For example on the f14 hot start campaign you start on the catapult ready for take off with the stick trimmed forward.

[Battlemage]

Hi erniedaoage,

 

thanks, thats a good point. I'll keep that in mind.