I am using the Mini Maestro 6/12 controller as an analog to digital converter. The analog source is connected to port 0. But it seems that the port influnces all other ports as displayed in the attached picture.
Both the Mini Maestro 12 and the Mini Maestro 6 are showing this behavior.
Thank you for posting the great picture; it really illustrated the issue well! It is normal for analog readings from one port to affect other ports in this way when they have a high impedance, such as when they are left floating. In general, reading the voltage from a floating port does not mean much, but you could connect any unused ports to ground if you want to get rid of the behavior.
Thank you very much Claire. The device works as intendet.