I have now learn a lot from different focuser project I have found and read about. I decided to go for the Focuser Pro 2, an open source project. It use an Arduino to control the stepper motor and it has a software and drivers both for ASCOM and INDI.
Here I have collected the information I found and what options I want to include, very basic because I controlled it from Raspberry:
When searching for the items I need to buily this I sometimes have problems to find them, maybe it's an old project and the parts have been replaced by new versions.