Reduce power to steppers when not moving

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12 Aug 2018 14:41 #115962 by Ralf
Is it possible to assign a pin that is only active when a move is done?

If possible I would like to utilize my drivers "power down" function, which reduces power to the steppers when full power is not needed, i.e. when the mill just sits idle, but still needs to maintain it's position.

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12 Aug 2018 18:01 - 12 Aug 2018 18:03 #115979 by PCW
One way is to feed motion.current.vel into the "near" component and then use the output of near to set the drives to low power mode when the velocity is zero or very close to 0 , something like:

loadrt near
addf near.0 servo-thread
setp near.0.in2 0
setp near.0.difference 0.00001
net velocity motion.current-vel => near.0.in1
net zerovel near.0.out => PinToEnableLowPowerMode
Last edit: 12 Aug 2018 18:03 by PCW.
The following user(s) said Thank You: tivoi, Ralf

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13 Aug 2018 07:17 #115990 by Ralf
Thanks, I actually think that I understand what's going on there.. ;)

Will test out tonight..

If I want to add a hysteresis to prevent powerdown from flickering up and down, could I abuse the debounce component, combined with an or gate like this ?
loadrt near
addf near.0 servo-thread
setp near.0.in2 0
setp near.0.difference 0.00001
net velocity motion.current-vel => near.0.in1

loadrt debounce cfg=1
addf debounce.0 servo-thread
setp debounce.0.delay 1000
net debounce-in <= near.0.out => debounce.0.0.in

loadrt or2
addf or2.0 servo-thread
net powerdown-1 or2.0.in0 <= near.0.out
net powerdown-2 or2.0.in1 <= debounce.0.0.out

net powerdown or2.0.out => PinToEnableLowPowerMode

I would assume that the or gate would be needed, since the debounce seems to work in both directions, and would would cause a delay before the steppers would be enabled on move, if wired directly to the output.

Or does a timer module exists, with a simple countdown function, instead of using debounce?

And where would I put all of this, custom.hal or custom_postgui.hal?

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13 Aug 2018 15:40 #116008 by Mike_Eitel
Use OR plus ONESHOT in parallel to rise current. OR in0 for moving and OR in1 for delayed reduziert
Mike
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14 Aug 2018 04:34 #116021 by Ralf
Oneshot seem to do the trick, together with velocity.

The following works out nicely in halscope.
loadrt near
addf near.0 servo-thread
setp near.0.in2 0
setp near.0.difference 0.0000001
net velocity motion.current-vel => near.0.in1

loadrt not
addf not.0 servo-thread
net moving not.0.in <= near.0.out

loadrt oneshot
addf oneshot.0 servo-thread
setp oneshot.0.width 1
setp oneshot.0.rising TRUE
setp oneshot.0.falling TRUE
setp oneshot.0.retriggerable TRUE
net moving oneshot.0.in <= near.0.out

loadrt or2
addf or2.0 servo-thread
net moving-inv or2.0.in0 <= not.0.out
net powerdown-2 or2.0.in1 <= oneshot.0.out

net powerdown parport.0.pin-08-out <= or2.0.out

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