Hi. I've never used Pi but maybe i can help.

First, in a previous post someone claimed it was a Mathematica issue and that their "packlet", if used, resolved the issue.

http://community.wolfram.com/groups/-/m/t/1116486

tell (us) the Output of

In[n]:=FindDevices[]

Make sure Pi is one of the devices and run examples to insure you can communicate with the Pi.

I don't see the "Sense Hat" as one of the Wolfram Connected Devices, though because it's for Pi it may not need to be in the list as a separate device.

The source code appears to connect to getfbdevice (ex. /dev/fb0) for visual output and uses IC2 (a bus protocol) to speak with the Pi.

I can't see anything in the examples or source indicating the Sense HAT acts as a driver in /dev/xxx. What I see is python script examples that instructs the device what to display on it's grid display (the device has it's own pixel display).

My concern is i see no specific driver "create to return only sense hat from the pi", for Mathematica or any program, to find. The python script itself uses the Pi driver. (that's found on the Sense Hat main page on Pi's website)

However the device appears simple to use using (Linux and the Pi).

in a python script one can read the hat and print data to a file (and mathematica can read files as (realtime) data):

from sense_hat import SenseHat
sense = SenseHat()
raw = sense.get_accelerometer_raw()
print("x: {x}, y: {y}, z: {z}".format(**raw))
print(sense.accel_raw)
print(sense.accelerometer_raw)

It seems like if you run commands in Mathematica to read the Pi, you can read your instrument by using those commands in the same ways the Python "library" does. Ask the Pi to return data, parse the data, use the data.