Any issues running Easy Driver v44 and NEMA17 PG-27 Stepper Motor?
Version 2 of the myFocuser Project
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brownrb
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Hello,
I am collecting the bits together to build the My Focuser Pro 2 basic build first, I was wondering if there has been any issues running the two together, in regards to current draw etc.. I have the Easy Driver board already and have just purchased the Arduino Nano to go with it. I have the Stepper Motor on the way, but if there are issues that may have popped up and I haven't seen in any documetation, then I will most likely go with the DRV8825 board.
In the future I plan to gather the parts to make the full kit, with Encoder and OLED display, but for now I am happy to just use a computer to control the focusing.
Any discussion apreciated. Looking forward to getting tis unit running with my scope. 8" F4 with moonlite Focuser, No Moonlite Steper though.
Andrew.
Hi Andrew
Not sure that I understand what you mean by "issues running the two together"?
The power for the drv8825 or easydriver comes from 12v.
The controller board is powered from the 12v-8v regulator and applied to the nano which then drops it down to 5v via an onboard regulator. The controller board uses < 1A. Adding OLED and encoder later will have little impact on current.
The easydriver board is ok to use. Similar to DRV8825 but more physical space. But I have managed to set a few on fire when breadboarding. Easy to get wires in the wrong place and the boards emit really nice bright red flames if you are not careful. After that, well, boards do not work once they have caught fire, that is my experience anyway.
So most controllers are powered by 12V external supply, and with the recommended NEMA17 motor at 400mA, it means total power draw is < 2A with everything fitted, oled, encoder etc etc. All you need is a power supply rated at like 3A or higher.
The USB connection is just that, it is for data, not power, as the Nano will derive its power from the 12V supply. That is why is can work in stand alone mode or with bluetooth and not have a usb connection at all.
Regards
robert
Last edit: brownrb 2018-07-03
Hi Robert,
The issues I meant were, current draw using the NEMA17 motor, I think you clarified that pretty well in your response though. I did have the EasyDriver circuit working before with a Arduino Uno clone. That was being used as a focus driver too, but using SGL Focuser code. It was a little clunky and I never really got good results from it, maybe since I wasn't using a geared stepper motor either, it was direct drive and I didn't tune the current either, if memory serves me right. this time, I plan on doing things properly. Thanks for your quick response, I'll let you know how it goes.
Andrew.