Telescope Autofocus with MyFocuserPro2 and 28BYJ-48/ULN2003
DIY MyFocuserPro2 for my new astrophotography setup with the 28BYJ-48 stepper motor and Uln2003 stepper controller, all controlled by the Arduino Nano.
I started astrophotography last year after aquaring the Sky-Watcher Sky Adventure i2 and an old used Canon 600d. A couple of weeks ago I received my upgrade from the ordinary Canon kit lenses, a Sky-Watcher Evostar 72ed Pro.
The whole setup is rather "flimsy" when trying to focus the scope, I guess due to the rather simple tri-pod (EQ1), and overall weight of scope/camera and tracker.
I have been using a Raspberry Pi 4 with Stellarmate for capturing/scheduling and focusing my Canon 600d and kit lenses, and searched the internet for diy solutions to the focusing issue.
After looking at Ardufocus and MyFocuserPro2, both DIY focuser solutions, I landed on the later.
The description of the focuser and required parts recommends the use of a Nema 14 or 17 size, but these being unavailable locally with the appropriate planetary gear for sufficient gearing ratio, I opted for the much cheaper, but also weaker 28BYJ-48 that could be bought for 79 NOK (10 USD), including the ULN2003 controller. Since the description mentioned the the motor could be to weak for the imaging train, I thought it could be strong enough if used on the fine adjustment knob, and as the video shows, it is working perfectly.
The video shows the prototype setup, and I intend to redo the mounting bracket at a later time, but first I'll test the setupwith the autofokus mode in Stellarmate as soon as I get a clear sky night 👍