Oops..[*]All HAT EEPROM have the same address.* Outside of pin conflicts this is the primary reason they cannot be stacked.
However, with respect to the specific case of stacking Sense HAT on top of Build HAT, I suppose it is still doable. Specifically, leave pin #17 of the 40-pin header unconnected. (For example, if you would use a tall header, simply cut pin #17 off..)
The reason one can do this is that the ID EEPROM circuit of the Build HAT can only be powered through pin #17. Meanwhile according to its schematics, the Sense HAT can still get 3v3 power through pin #1.
Statistics: Posted by muzkr — Fri Sep 27, 2024 9:13 pm