persistent error...ERROR - logic.lua:9: attempt to call a nil value

[NikTB]

Hi
So, I'm getting to grips (read: reacquainting myself) with script writing to build switch panels for my Flight deck, migrating from SimVim.
I've managed to geta few switches working without an image on the panel. Whilst building the panel, want to add the image of the switch or button...

So, run the videos and copied the switch and button scripts/amended, your basic as follows:

function propsync_pressed()
print("I am pressed!")
end

function propsync_released()
print("I am released!")
end

propsync = button_add("press_off.png", "press_on.png", 50,50,100,100,propsync_pressed, propsync_released)

RUN the script and get - ERROR - logic.lua:9: attempt to call a nil value (global 'button_add') I've written several scripts for variations of adding an image and xxx-add persists in this error...

The .png are located in the correct resource folder and I just cannot fathom why I get this error.

Its gota be a basic mistake ... can you point me in the right direction, please.

Thank
Nik

[Ralph]

The button add is the virtual button. In hardware functions you'll need to use hw_button_add

[Sling]

What you posted should work if it's used in an instrument script rather than a hardware function script.

As Ralph said you can't generate any graphics from a hardware function script.

[Nik201]

Hi Guys
Thanks.. for refreshing my knackered old memory!!
Yeh.. worked with instruments... Duh
Still thrashing around ... Getting there slowly.
As ever grateful ...
Cheers
Nik