Hi Kane,

is there a way to use the AS5600 as a quadrature encoder?

cheers

tanc

Hello,
I did not understand absolute.

1 revolution = increment 40909
1 increment = 0,0088°.

Current on: position 5000 [increment] = 44,0001°.
Current off: Position changes manually to 40000 [increment] = 352.0008°.
Current on: what value do I get?

Sorry, I translate with machine

does the as5600 hold absolute angular value when powered off? kind of noob question but i cant find the answer anywhere. 

As long as the magnet doesn't move it knows absolute shaft angle

How large or powerful does the magnet need to be?  Do you have a recommended size?

Hi Matt,

I've been using and supply these with the boards I have sold.

https://magnet.com.au/neodymium-disc-6mm-x-2-5mm-n35-diametrically-magnetised.html

The encoder had automatic gain control so it will cope with a wide variety of magnetic strengths. Just make sure that the magnet is diametrically magnetised (along the diameter). The size does not really matter since it is the alignment of the magnetic field is used to determine the angle.

Hope this helps.

Thanks, yes it helps.  I was wondering if there was a lower limit to the size...but I certainly have room for the 6mm size.

Thanks for your schematic, but how can I use this to access Ramps and Marlin? 

I'm not familiar with the Ramps or Marlin system. The current design is not yet adapted for existing systems. Perhaps a possible design feature in a future version 

yea! thanks man, this is what we need, cheap / concise servo motor controller, good job! looking forward to your hardware files

I did my dissertation on a project which used a very similar setup. Looking cool!

Thanks Sam,

Closed-loop control is an interesting topic with plenty of research still to be done, particularly in the efficiency of driving methods. I'd be ken to know what your dissertation was on.

Kane,

My dissertation was looking at the use of closed loop BLDC motor control to actuate rotary haptic feedback effects. Essentially making a BLDC motor feel like a variety of different controls when turned by hand, through the use of software.

I really enjoyed it and wished I could have spent more time on it. I often think about revisiting it in my free time. Your project is an inspiration to do just that and would likely give me a starting point. At university, I was following on from a student from the previous year, and was using a laser-cut enclosure to hold the motor above the sensor in the correct location. My project also used a magnetic field sensor.

Sumix, I see you have full PID solution. Any thoughts on the simplified digital paper? May save some time over full PID for this application.

AlanX

AS5600 has the problem with the wrong occour between two byte . Be careful!

Thanks, can you clarify what two byes you're referring to please? 

HI,Kane,  You can see there https://github.com/uStepper/uStepper/issues/4

AS5600 is not good at continuous rotation problem;

Very slick, should make a lot of projects easier. Can't wait to see the details.

Thanks Dan, shouldn't need to wait too long hopefully. Slowly getting everything ready to publish.

Magic, I was looking at this problem recently for my SCARA to control oscillation (overshoot/undershoot).

There is a paper for a simple digital PID controller that sits between the Controller (i.e GRBL) and the stepper motor drivers. If you put an AVR on board (perhaps as the holes for an ATiny85 or similar) then the solution would be complete.

https://pdfs.semanticscholar.org/177a/858daa1b8c0cee930c7d315c1c711ccabb3b.pdf

Regards AlanX

Thanks for the feedback Alan. I'm currently doing research into incorporating an onboard microcontroller and potentially a motor driver to compensate for any missed steps. I hope to be updating this regularly over the coming months. 

Kane

In case you haven't, check out https://tropical-labs.com/mechaduino/

It's a great idea and is awesomely open-sourced. I have had this on my list of cool projects to fork and play around with but i just haven't had the time.

I'd love to see your take on closed loop stepper motors!

I wasn't aware of the Mechaduino sumix however I have come across the uStepper (http://www.ustepper.com) which is very similar. These are excellent products and have enormous potential. 

Having an all in one solution is a valuable resource, however, the user is limited to the functionality of the onboard microcontroller and motor driver. This is why the primary focus of this project is to find the middle ground between products like the Mechaduino/uStepper and open-loop control. By providing a standalone encoder solution the types of applications can vary greatly and expand to incorporate the most suitable hardware for a users need.