Sorry to reopen an old thread but I’m trying to do something similar with unicorn hat hd. I can’t seem to be able to use a 40-cable or individual wires, though when plugged in directly it works just fine. Is there a similar ground preference?
A 40-pin cable should absolutely work- I use one most of the time to hook up HATs and pHATs since my workstation Pi’s are enclosed in cases.
How are you connecting the cable to the HAT?