I am trying to find a work around for a rotary button that only has a push-function but not a pull-function. I want to use it in an Airbus home cockpit for the Baro encoder that in the real airplane is push/pull. My plan is that if a push sends a push command (ROTOR_BRAKE plus parameter) to FSUIPC, the next push will send a pull command. So while the button can only be pushed, it will send alternating commands. I have experince with the EPIC programming language that is similar to C++, but I cannot find information how Lua handles flags. Anyway, this is what I came up with, and it does not work:

local i = n            -- defining the local variable

    if i > 1 then
        ipc.control(66587,71008) -- command for pushing the Baro knob
        ipc.control(66587,71011) -- command for releasing the Baro knob
    i = 1            -- setting the local variable to 1 in order to continue with "else" for the next push
    else
        ipc.control(66587,71007) -- command for pulling the Baro knob
        ipc.control(66587,71010) -- command for releasing the Baro knob
    i = 2            -- setting the local variable to 2 in order to continue with the first command for the next push
    end

I would be happy for any advice. If this is not the right forum for these questions, please let me know.

Best regards,

Holger

I'd do it by putting the state flag into a user offset, which persists across lua script executions.  For your example to work, you'd have to keep the script running in a loop (to keep the state variable "i" alive) rather than just executing it once each time the button is pressed.

e.g. (using user-area offset 66C0 as an example)

btnstate = ipc.readUB(0x66C0)
if btnstate == 2
  then
    ipc.control(66587,71008) -- command for pushing the Baro knob
    ipc.control(66587,71011) -- command for releasing the Baro knob
    ipc.writeUB(0x66C0,1)
  else

   ...etc

That said, I think it would be better to code your "pull" action for something like a press-and-hold > 1 sec rather than alternating the press-pull actions.

Dear Bob,

Thank you so much for your advice. This is what the script looks like now, and it works, even without running in an infinite loop. I think this is because the value is stored in the offset. Thank you again so much!
Best regards,
Holger

P.S.: For the record: This is for the FSLabs Airbus (FSX) EFIS Baro knob. The display alternates between "Std" and the selected QNH with every push of a button now. But the command for releasing the button comes too quickly, so I have lost the animation. I understand that there is no wait function in Lua, so I will have to carry on tinkering until I find a solution.

btnstate = ipc.readUB(0x66C0)
if btnstate == 2
  then
    ipc.control(66587,71008) -- command for pushing the Baro knob
    ipc.control(66587,71011) -- command for releasing the Baro knob
    ipc.writeUB(0x66C0,1)
  else
    ipc.control(66587,71007) -- command for pulling the Baro knob
    ipc.control(66587,71010) -- command for releasing the Baro knob
    ipc.writeUB(0x66C0,2)
end

 

7 minutes ago, EPICfan said:

P.S.: For the record: This is for the FSLabs Airbus (FSX) EFIS Baro knob. The display alternates between "Std" and the selected QNH with every push of a button now. But the command for releasing the button comes too quickly, so I have lost the animation. I understand that there is no wait function in Lua, so I will have to carry on tinkering until I find a solution.

I'd think adding a 1/4 sec sleep delay between the controls should fix that:

...

    ipc.control(66587,71008) -- command for pushing the Baro knob
    ipc.sleep(250)
    ipc.control(66587,71011) -- command for releasing the Baro knob

...

 

I just tried this (below) and it worked. But your solution works, too, and it is much more elegant. Thank you very much! This is my first day with Lua, I haven't coded for years, and its like coming back home.

local clock = os.clock
function sleep(n)-- seconds
local t0 = clock()
while clock() - t0 <= n do end
end

btnstate = ipc.readUB(0x66C0)
if btnstate == 2
  then
    ipc.control(66587,71008) -- command for pushing the Baro knob
sleep(0.2)
    ipc.control(66587,71011) -- command for releasing the Baro knob
    ipc.writeUB(0x66C0,1)
  else
    ipc.control(66587,71007) -- command for pushing the Baro knob
sleep(0.2)
    ipc.control(66587,71010) -- command for releasing the Baro knob
    ipc.writeUB(0x66C0,2)
end

 

Most importantly, the ipc.sleep function suspends execution of the script rather than going into a tight timing loop, which is a potentially important consideration when coding real-time processes.

There's a lot of useful functionality built into the Lua library for FSUIPC.  I never cease to be surprised at how much one can get done with simple Lua scripting using the FSUIPC library.