Autofocuser for A4988

[Idefix2006]

Hi,
we have successfully installed the software on our Raspberry Pi4. We have a selfmade autofocuser with the A4988 driver and a Nema17 motor. Unfortunately, so far the software only supports the 28BYJ-48 driver. Does anyone have a solution to the problem or has already used the software with our equipment? Or even better, perhaps an integration is planned or simply implemented?
Thanks for the answers

[aaronwmorris]

I will take a look at this.

[aaronwmorris]

I have merged #1848 which should enable A4988 NEMA17 stepper support for the focuser functionality. If you are able to use this, please let me know since I do not have this hardware available to test.

[sdh1605]

Thanks very much for the quick implementation. So far we have successfully been using the A4988 and NEMA with KStars/Ekos and the Astroberry Focuser driver. The Pins we use there are:

I have tried the focus with Indi-allsky assigning D26 to DIR (GPIO Pin 2), D19 to STEP (GPIO Pin 1) and different combinations for GPIO Pins 3 and 4 (D17,D13 / D17,D27 / D13,D17 / D22,D13). None of them were successful. Do you have other suggestions for the use of GPIO Pins 3 and 4? Or maybe the implementation of the A4988 driver board needs some adjustments according to the Astroberry Focuser Indi driver? Thanks again for the help.

[aaronwmorris]

First I would start with the minimum of just the two pins for DIR and STEP in full step mode. Pin 3 is optional if you want to implement half step mode. (Pin 4 does not do anything currently)

I tested with my Pi4 with an oscilloscope and the pins appear to be functioning as expected. I based my code on examples I found online.