Controls on overhead, specially for big airliners, are the most complicated part to activate on home cockpits with the default FS2020 planes.
My experience up to now with Arduino and Fsuipc / Mobiflight or even direct to simconnect, is that only 30-40% of the functions are working, and even less with default parameters or event-ids.
Very basic and simple commands like “nav lights” or “taxi lights”, or “hyd pumps”, “apu start”, etc, are not working or require a lot of trial and errors before even become partly usable.
No documentation is given for custom vars (on XPlane you find a complete list of datarefs for the Laminar B737 and you can use them easily), there is nothing like “dataref tool” to view the undocumented vars…
Even so, I managed to get working (with many “tricks”) the following controls:
- landing lights (only one)
- beacon lights
- cross feed valve and annunciator
- apu starter % (has to be set repeatedly to 100% - I use SIOC or lua for this)
- apu stop
- apu rpm indicator (with stepper motor controlled by MobiFlight)
- apu bleed and annunciator
- apu generator
- generator 1 a/b and generator 2 a/b and gen off bus annunciators
- generator 1 and 2 source off (when gen switch on and engine is not running)
- fuel pumps and Low press annunciators (partly faked)
- hyd pumps and annunciators (faked with fsuipc free offsets for the moment)
- yaw damper (AP yaw damper and annunciator - sometimes disconnecting by itself)
- battery switch (not always working as expected but responding)
NOT working at the moment:
- nav lights (is only connected to other lights)
- start knobs, gnd, cont, etc - seems not working from cold and dark situation
- taxi lights
- isolation valve
all of the remainig controls
- pitot, wings, windows, engine anti-ice
- windscreen wipers
- ground power
It would be interesting to collect informations among all home cockpit builders on this subject!