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pkerspe / ESP-FlexyStepper

This library is used to control one or more stepper motors from an ESP32 device. It is based on the FlexyStepper library by S.Reifel but provides some additional functionality
MIT License
150 stars 32 forks source link

Deceleration with position rather than speed. #12

Closed dcentri closed 2 years ago

dcentri commented 3 years ago

HI,

Thanks for this awesome project. Am having an issue with the setTargetPositionToStop() function. I was trying to achieve continuous motion with the library and settled for calling setTargetPositionRelativeInSteps(CONSTANT) so I basically extend the relative position whenever the target is almost reached. I just realized there is two issues with this.

  1. When I call setTargetPositionToStop() to decelerate to a stop it sometimes takes as much time to stop as It has been running. This, I think is because it uses the position to decelerate instead of the speed.
  2. setTargetPositionRelativeInSteps(CONSTANT) seems to accumulate the relative position and thus could overflow eventually

Is there a way to fix the setTargetPositionToStop() so that it decelerates as per speed not position and is there a better way for continuous motion?

pkerspe commented 3 years ago

Can you please describe what you actual goal in your project is? If you only want to spin the motor for an unlimited time at a constant speed, this libaray is totally overkill, you can just setup the PWM module of the ESP to output a PWM signal with the required frequency and you are done. If you need a specific number of pulses only you can combine with the hardware pulse counter module. I posted a example code in the Issue #4 (https://github.com/pkerspe/ESP-FlexyStepper/issues/4#issuecomment-774678853)

dcentri commented 3 years ago

I am working on a paper separation mechanism. Kind of like a printer, picking a paper from a stack but with a lot of variability on paper size and type. I need to coordinate 2 motors as per my design.

I have limit switches that start and stop the the motors and everything seems to work well, except that when I call the setTargetPositionToStop(). The motor seems to keep moving as though it is more corelated with the targetPositionRelativeInSteps other than the motor speed. I would expect the deceleration to be the same at the same speed but this is not the case.

I had a look at the PWM example and for my application the library has all the required features(background task, variable speed, acceleration/deceleration, easier to manage multiple motors ++).

I hope this clarifies things and a huge thanks for your work!

pkerspe commented 3 years ago

Please provide your complete code you are using for further checks