Tip : S-Pen/Touch Testing The Android way
Thought i'd post this useful hidden feature to test/check your digitizer/s-pen as well as pressure on Note 8 (should likely work for mouse too)
It can be enabled/toggled under Settings > Developer options > Input > Show Pointer location
It will draw cross hairs at your touch location as well as give you some data points.
such as described below
P =1 when touched; Otherwise P=0
dx/dy (delta x, delta y) (offset between location touched and location released, basically drag/stroke offset)
X,Y Screen Co-Ordinates of your touch location (when touched).
Xv/Yv (velocity tracker values for Hori/ Vert resp)
Prs: Pressure Level (0>P<=1 for s-pen, P=1 for finger ) (max pressure i have been able to achieve is around 0.88 that too by adjusting the internal controller inside the s-pen.)
Size: size of your touch region co-ordinate (with finger) value is Zero when using s-pen.
Hope it helps the curious!
for those who want to look into some details , nothing better than the android source code (java) :