I’ve built an electronic automatic focuser (EAF) for my Vixen R114 reflector for automated and precise focusing. The focuser was built with a geared stepper motor, A4988 stepper motor driver, and an Arduino Uno.

The focuser is ASCOM compliant and works with astronomy software such as the Nighttime Imaging N Astronomy (NINA) for automated focusing during unattended imaging. To watch a video showing the focuser’s movement, click here.
Related links:
DIY Electronic Automatic Focuser (EAF) | Refractor
DIY Electronic Automatic Focuser (EAF) | Telephoto Lens
Night Sky in Focus © Anthony Urbano | Bacoor, Philippines