Hi Bojan,
Now I have done some more test, works very good. Just one problem, my stepper motor have very low impedance, the DC resitans is only 2.2 Ohm and it doesn't work very well with the DRV8255 driver and 12 Volt, need another stepper motor, but not worse than I could use it.
Added some more pages with information:
http://www.astrofriend.eu/astronomy/...us-driver.html
I have now take out the dust collector, my TS130 APO refractor. 3D-printing new tube rings for the guide telescope I will use until I switch over to off-guiding technology. I have also changed my Vixen dovetail to a shorter one to make mor room along the telescope tube. Rebuild the dew heater band to lower power. I designed it for 8 Watt which was too powerfull, now I aim för 3 Watt. The dew heater for guide telescope will also be reduced in power. Lower power means smaller battery.
Lars