Mixing different HATs, beware of addressing conflict

Doc Garret

New member
this post is merely posted as feedback rather than a question.. And i hope i did my research properly. šŸ™ˆ
While building and programming a setup with a 8 HV Input card and a 8 relay i found that the output card was also controlling my input card.
Several manuals are stating something similar like the next quote and i quote from the relay manual : Up to eight 8-RELAYS cards can be stacked on top of one Raspberry Pi.

As this is entirely true when you only use the same cards. But this is FALSE, when you use other cards as well, based on the same chip.

Maybe it would be better to make a list of cards, which are based on the same chip. ( xCA9534 )
So when you are using one of the next cards, you can mix those up to eight ( and have to have set their own I2C address set with the (dip)switches.

Maybe others can kick in to complete this list ?


New member
Just to clarify, are you saying the cards on the list can be mixed in a single setup (up to maximum of eight in total)? Or that they can only be used with other cards of the same type?



Staff member
The cards on the list can be used with a single stack up to 8 in total (does not matter if is a single type or multiple types from the list). On the same stack can be added cards that are not on the list up to 8 of each type.