Hi Mo
I have the Arduino flat panel working from Voyager. It can be preset to a know brightness and Voyager will set the exposure to get the correct flats for you Camera. Or you can have Voyager try to set the brightness if you need to set the exposure time.
This is the page you need to look at
I am using a Arduino Uno connected to a cheap artists sketch panel.
I also have the Flip Flap addition to the code working from Voyager.
If you need any further help, mail me.
Regards
Graham