I'm considering purchasing a RTC extension card (This one for instance).
But this card would be in contact with many GPIO pins.
There are probably unused pins, so I assume I still could use the others with other stacked components. But that's not the first time I see other extension cards connected to many pins, but that still permit to stack many extension cards, using the same pins.
Aren't there conflicts sometimes or is there something that permits to share a GPIO pin with many equipments?