Aspen EFD 1000 interface and RasPi OS Bookworm

[Mito173]

Hello out there,

I have started my 'career as sim XP12 sim pilot' only recently. After some time flying my BN-2A Islander with the instruments on the main displays only, I decided build myself a little cockpit panel. Central instrument for this will be the Sim Innovations Aspen EFD 1000, which is displayed on a 7" HDMI TFT connected to a Raspberry Pi 5B 4GB, running AirPlayer.

The instrument itself is running fine on the RasPi, as you can see in attached image AirPlayer_Aspen_Raspi_Display.jpg.

Next step was to add and configure the Aspen EFD 1000 premium interface, see attached image AirManager_Aspen_Raspi_GPIO.png

Unfortunately, switching the selected GPIO pin on the RasPi (by connecting it to ground) has no effect. I tried with different Buttons, GPIO pins and even performed the steps described in the forum post 'AIR PLAYER 4.2.9 for Raspberry BUG REPORT #1 (Issue: GPIO Autoplay)' - the GPIO pins won't trigger any change in the Aspen instrument panel.

I have to admit that I never used the Raspberry Pi I/O pins before and do not have much knowledge on it. Though, what I found is the following forum entry:
https://forum.fhem.de/index.php?topic=137661.0
It basically states:

Access via the sysfs-gpio interface (/sys/class/gpio/export) is no longer supported starting with Bookworm.
The new method works with gpiod tools (debian package) or pinctrl (Raspberry Pi OS tool).

So I guess, Air Player is using the old, no longer supported method? If yes, does anyone know how I can work around this and get the hardware interface going?

Thanks a lot in advance!

Kind regards,
Michael