Help for wiring up CNCv3 - DRV8825 -R32 - D1 #esp32 #wemos #250p #arduino #d1



my name is Stefan. I'm newbie in terms of telescopes and just bought a Skywatcher Dobson 10" 250p.
I came across this awesome site full of great ideas and switched my former Intention to build a cnc machine, to motorizing my Dobson.

I do have most of the parts shown at this wiki entry, which does supply a lot of information, but unfortunately not detailed enough for me.

 I'm not the best electrician (although I try to get better :)), so I do have some missing knowledge on wiring up the components.

I own this kit:
  • 3 Nema 17 1.8 200 steps
  • 4 DRV8825
  • Cncv3 shield
  • 3 Endstops
  • D1 R32
  • D1 mini
  • DS3132RTC
  • GT-U7 GPS
  • BME/BMP280
  • Active Buzzer 5v
  • 3d printer
  • soldering station
  • elect. accessories (capacitors, etc.)

Of course I know that with this kind of components there is not much to expect in terms of accuracy, but I would be glad to use it as guiding help for visual scoping
and to learn more about the night sky, telescopes and the ecosystem around it.

My scope with 3d printed gears and endstoppers: 

Gear reduction on azimuth 44:1 and altitude 22:1

I read the wiki up and down and found a lot, so that I was able to tune the stepper drivers to 0.75A.
Configuring OnStep and uploading it to the R32 worked and I was able to steer both steppers manually with the Android app.

Goto did not work for me, as the dobson just turned around in circles after setting it up aligning as described here.

So there a few questions, I do not find an answer for and would be very pleased if someone could shed some light into it.

  1. DRV8825 the 1.5A (0.75A) are without heatsink - I read somewhere that with heatsink 2A (1A) max is possible, true and does this improve something?
  2. Is OnStepX possible to run the SWS on the same R32 or do I always have to use the D1 mini additionally
  3. How would I connect the D1 mini to use the SWS for accessing OnStep?
  4. I did not get the endstoppers to work, when configuring the as LimitSense Low - I guess also the wiring was wrong...
  5. How do I wire up the additional components? It was not possible for me to get them to work, I think the reason is setting the correct pins.

Here are images of my components as well as my current config for OnStep:

Any help would be appreciated, thank you!

Best regards


Join to automatically receive all group messages.