How to detect if elevator trim is changed manually ?

[bcs112 0]

Hi,I'm finishing up my A300B4 panel right now (C gauges and freeware) and I'm trying to add the final touches. One of the things I haven't been able to do was add the trim wheel sound that the real panel uses when the elevator trim is changed manually (so not when the AP changes the trim). Manually trimming while the AP is turned should also disable the AP.So how do you detect this ? Anybody have an idea ?Thx,Bj

[Guest HartmannH]

You can either store the last trim setting in a variable and compare it to the current setting to detect changes or use an event handler which captures keyboard/joystick input:// Prototypevoid FSAPI msys_EventHandler(ID32 event, UINT32 evdata, PVOID userdata);// in your gauge callback function:case PANEL_SERVICE_POST_INSTALL:register_key_event_handler((GAUGE_KEY_EVENT_HANDLER)msys_EventHandler, 0);break;case PANEL_SERVICE_PRE_KILL:unregister_key_event_handler((GAUGE_KEY_EVENT_HANDLER)msys_EventHandler, 0);break;// and the event handler function itselfvoid FSAPI msys_EventHandler(ID32 event, UINT32 evdata, PVOID userdata){switch (event){case KEY_ELEV_TRIM_DN:case KEY_ELEV_TRIM_UP:// do something herebreak;}}That should do what you want.

[bcs112 0]

Hans,Thing is that, as far as I understand, the FS autopilot also uses the trim to make changes in the aircraft pitch so detecting a change in the trim will not detect wether this change was made by the autopilot or by the pilot. Bj

[phjvh 0]

Hi,In XMl I should add a custom variable to generate sound when trimming manually.May be in C++ that is possible too.Jan"Beatus Ille Procul Negotiis"

[bcs112 0]

Jan,That's what I plan to do, but how to distinguish manual trimming from FS AP trimming ? That's the question !Bj

[Guest HartmannH]

The event handler code I posted above, only reacts on key commands, not on trim changes made by the autopilot. This is actually the code I used on the Flight1 ATR to switch off the autopilot when the user moves the yoke.

[bcs112 0]

Thx Hans,Will give it a try tonight, I'll keep you posted how it works out...Bj

[phjvh 0]

I use this one to see when AP is trimming:(A:ELEVATOR TRIM PCT,percent) (>G:Var1) (A:AUTOPILOT MASTER,bool) if{ (A:ELEVATOR TRIM PCT,percent) (G:Var1) 0.1 + > if{ 1 } els{ (A:ELEVATOR TRIM PCT,percent) (G:Var1) 0.1 - < if{ 2 } } } els{ 0 }Manual trimming disconnects the autopilot through the custom var.Jan"Beatus Ille Procul Negotiis"

[bcs112 0]

Hans,Tried the code, is it possible that this is FS2004 only ? Can't seem to get it to work in FS2002. Is a similar interception of events possible in FS2002 ?Bj

[Guest HartmannH]

No idea, sorry. I never tried this in FS2002.

[Guest HartmannH]

deleted... answered without thinking ;)

[bcs112 0]

Well works fine in FS2004 so thx a million for the great tip !Bj