Hilleskog:
So I should try to find the common GND of the built in RGB controller and share it with the Arduino and use it as GND for the voltage divider as well?
Yes that is how it must be done.
Hilleskog:
So I should try to find the common GND of the built in RGB controller and share it with the Arduino and use it as GND for the voltage divider as well?
Yes that is how it must be done.