MobiFlight Community Support

Hello

I have configured a Mega 2560 R3 into a Mobiflight board and used the Servo tutorial to set up a test servo to motorize a throttle quadrant. My Mobiflight version is 7.4.0 and the Arduino IDE version is 1.8.5. The servo is a MG995 Tower Pro. I am using the FSUIPC Offsets 088C and 0924 (output for Throttle 1 & 2). On the display tab, when the settings are Min 0, Max 255 and the Test button is pressed, the servo moves its full range. When the Stop button is pressed it moves back its full range. The full range for the throttles, according to FSUIPC is -4096 to 16384. When these values are placed into the Min Max values, the servo doesn't work.

Hi

At first please check if your AddOn ( if you use one) is working with that offsets....

simply use this two configs and not use the Servo for device.... ( No device selected) ....
Now start Sim and work with the Throttle..... In Manual Mode and by Autothrottle.

Please find out how the Offset workes ( I not do a autothrottle till now.... so i get no direct experience)

*****
If Offset is ok and logical maby your problem is the negative Value in the Servo setting ( Not shure if this is possible....
Maby you can tryout the follow....
Use TRANSFORM Enable and say $+4096
For Servo Value you use MIN:0 MAX 20480 ( You simply add the 4096 here, too for MIn and Max)
Now Servo Value is alway positiv..... Maby this already helps!

Please reply experience !

I am beggining to work on a autothrottle quadrant for my PMDG 737 and I indeed was succesfully on getting the levers moving accordling. However I am not being able to do the opposite: mannually move the levers, once the servos I am using lock on their current position.
I've tried using a stepper motor instead, but the result was the same.
My questions are:
1) should I use a servo or a stepper motor?
2) is there a way to put the servo or stepper motor in a 'neutral' mode (maybe powering it off)?
3) is there an specific model of servo or steper motor that allows to be mannualy moved from its current position?

Thank you.

Decio

A Motor axis can not controlled manualy while its powered cause it always try to turn back in that case.

Thats why we talk about this in lots of different topics in the past.....
In a Real B737 it is possible to "overdrive" the Throttle.... You can controll it by hand whatever the AT is ON..... In that case the Motor will not work against you.....
In the Simulator this is difficult.

A solution is to disconnect Autopilot always if you like to controll throttle Manualy..... With a relais you can cutoff electirc power of Servo to make it moveable,
Then you can use only a Servo ! A Stepper miss Zero point Position after you cutoff power !

Professional Cockpitbuilders do this with hall sensors or photocell .... They use coupling systems for example.... So the Motor can get temporary physical offline.
But in that Case the Motor not know the Throttle Position.... Thtas why you need a indicator like the sensors!

Final Problem then is.... You need a logic that tell the motor it should use this sensor information to recalibrate..... and this is not possible with Mobiflight.

So for a 100% Real situation you need own Code i think (Maby in combination with Mobiflight or complete external).
A improvisional solution should be possible with mobiflight like i said above .

Hi, Pizman!

Thank you for your very detailed explanation. It is much more clear for me now.
Cutting the power off with a relay sounds a good idea.
I'll check it out.

Decio