I have a Raspberry-Pi 3 with a Sense Hat connected. The Python 3 application can find, query, and write to the Sense Hat. However, in Mathematica
FindDevices does not find it and
DeviceOpen["SenseHAT"] shows a couple of errors about pins before it says that a Sense Hat could not be found.
How do get Mathematica on the Raspberry Pi to see the Sense Hat?
The Sense Hat works because the Python 3 app can see it. Therefore, I think it is a Mathematica issue.
Note that online Wolfram Language reference link for Sense Hat is broken (only has Japanese and, I think, Mandarin) but the installed PC desktop (not Rasberry Pi desktop) documentation does have it in English.