Is the MKS and BigTree closed loop stepper the same? I see more responses to BigTree question. I read BigTree was plug and play and seems to be getting good support from them. I'm using the MKS product and trying to go from a standard Nema17 to the MKS Closed Loop. Using PlatformIO C++, Arduino Nano, DRV8825 with the expansion bd. When using the MKS42b the driver is removed and replaced with the adapter and cable to the MKS. I can run the simple code provided in GitHub but can't get beyond that.
I'm stuck for now, I'm just trying to move the stepper to a given position (degrees) when ACS712 senses an AC current. If I can accomplish that I can move on to the array set up.

Over view of project:


Description: For use with vacuum system for dust collection in a woodworking shop.
Consists of one stationary round disk with holes arranged every 45°, 8 “ports” total each leading to a specific tool. Mated to this is a secondary disk that rotates with one matching port that aligns with the stationary ports 1 at a time as rotated. This assembly can be operated manually or automatically via this program. Using an Arduino Nano Microcontroller, ACS712 current sensors, and a Closed Loop stepper motor.
In simple terms,

  • Each current sensor is connected to an analog port and detects when that tool is turned on.
  • Each port is assigned a specific position that the stepper is programmed to 45, 90, 135, 180 ... 360°.
  • The digital output from the Nano would tell the stepper to go to that position. The Closed Loop stepper remembers its current position and would remain in that position if it is already there. “Using same tool repeatedly”
  • $\begingroup$ Sorry, but this question is not clear what the problem is. Please rewrite the question. E.g. what top question is meant? Why mention BigTreeTech? Who is you? All that is not relevant and distracting from the problem. How do you run code in GitHub? You mention NEMA17 and later AC? This almost qualifies for those automatically generated posts that technically describe something, but in the end are SPAM posts. Please rewrite the question to make it more understandable so we know this isn't a SPAM post. $\endgroup$
    – 0scar
    Feb 24 at 22:56
  • $\begingroup$ Sorry I wasn't more clear, Was trying to get question about earlier post I read. I edited the post and hope that helps. Not a Spam Post. The only AC I see is reference to ACS712 Current sensor. Was trying to explain my project, guess not doing very well at it! $\endgroup$
    – Greg
    Feb 28 at 21:17
  • $\begingroup$ We get spammed frequently with questions that look like questions but are not. Thanks for the update. I don't see the benefit of the closed loop stepper driver, once powered off, it will forget the position anyways. I would turn the selector disk on startup of the controller, using a mechanical endstop or an optical. From that point you'll know the position, I don't think the disk is that much stressed to require a closed loop controller. $\endgroup$
    – 0scar
    Feb 28 at 23:04
  • $\begingroup$ 0scar is exactly right. Use a single endstop switch connected to a digital port on your Nano, for the secondary disk, and you'll know where it is when the switch is tripped. Then it;s just a matter of counting the steps to the correct hole alignment. $\endgroup$ Mar 2 at 0:09
  • $\begingroup$ Thanks for the input. I did think I would need a homing routine when the system is turned on. After that, my thought was that the closed loop stepper would be easier to code since it would keep track of its own position. Staying with the degree setup, I may use a tool that would go from 90*, then to 180* and then to 45*. Plus was thinking of adding code for the shortest Direction to the next position. I guess this is possible with steps and starting over if it past home?ec $\endgroup$
    – Greg
    Mar 2 at 2:21

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