OpenHAB Exec Binding explained in detail on 433MHz radio transmitter example

Can you execute the command from commandline as user openhabian?

Why do you fiddle with sudoers?
Did you add openhabian to the gpio group?

What do you try to achieve here? Wohnzimmer ist a switch which can be on or off. Not a string.

Please try to follow the instructions step by step.

  1. Execute the command as user openhabian and post the result.
    Maybe the returned information will help getting the command to execute, mostly by adding the user to the group. Soduer rights are mostly not required.

Please remove all other stuff, as there are errors listet in the log which obviously contains data which is not listet here, which has errors.

And please use the preview to make sure the formating is properly, also or even more when copy pasting.

Sometimes/often it helps to restart the rpi when the files are changed a lot.

If it is really necessary to get sudoers for openHAB it is explained here