Hello,

i've no solutions for the driver, but yet (after one day over it) it works ...

Hitecastro DC Focus, Ubuntu Mate 16.04LTS, PI3B+, Kstars/ekos

I've removed definitively the powered USB HUB, and after many many tries it works with this parameters:
Polling 5000ms (yeah, 5 seconds)
Speed 50 or 100 (<50 no function)
Max travel 10000

Steps: between 4000 and 10000 it runs but no update for the position (tiks)
between 20 and 4000 it runs perfectly, only wait 12s (12 seconds) to launch another command

Position: for a move of 2000 steps, the position move of 4000
many tries: always x2

no safe position (limits visible in .cpp)
override below 0, i've reached -2200
I didn't test the override > 10000 (Max travel ?)

At startup the tiks (position) is always 49800 (position not saved)
all others parameters are correctly saved

Read More...