Mesa 7i96 to spindle FWD/REV control
19 May 2021 13:05 #209502
by PCW
Replied by PCW on topic Mesa 7i96 to spindle FWD/REV control
Set the PWM scale to 3125
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19 May 2021 14:55 #209516
by mhd325ic
Replied by mhd325ic on topic Mesa 7i96 to spindle FWD/REV control
It works to match the high end rpm. One step closer.
Can we add offset as well? When I add the following line in hal file, it complains about unknown parameter of offset.
setp hm2_[HOSTMOT2](BOARD).0.pwmgen.00.offset 0.027
Can we add offset as well? When I add the following line in hal file, it complains about unknown parameter of offset.
setp hm2_[HOSTMOT2](BOARD).0.pwmgen.00.offset 0.027
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19 May 2021 15:09 - 19 May 2021 15:10 #209517
by PCW
Replied by PCW on topic Mesa 7i96 to spindle FWD/REV control
There is no offset parameter for the PWM gen
but you can do it by adding a scale component
or if you want to get really fancy, curve-fit
by using the lincurve component, but note
that actual spindle speed matching is rarely
important if its with 20% or so
but you can do it by adding a scale component
or if you want to get really fancy, curve-fit
by using the lincurve component, but note
that actual spindle speed matching is rarely
important if its with 20% or so
Last edit: 19 May 2021 15:10 by PCW.
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19 May 2021 18:22 #209533
by mhd325ic
Replied by mhd325ic on topic Mesa 7i96 to spindle FWD/REV control
I setup a lincurve as lookup table from 0-2000 and replaced the net line in the hal file
net spindle-speed spindle.0.speed-out => hm2_[HOSTMOT2](BOARD).0.pwmgen.00.value
with the following two lines
net spindle-raw spindle.0.speed-out => lincurve.0.in
net spindle-corrected lincurve.0.out => hm2_[HOSTMOT2](BOARD).0.pwmgen.00.value
Now, only the spindle can only excute CW rotation and no CCW rotation. Is it because of the negative sign in spindle.0.speed-out?
net spindle-speed spindle.0.speed-out => hm2_[HOSTMOT2](BOARD).0.pwmgen.00.value
with the following two lines
net spindle-raw spindle.0.speed-out => lincurve.0.in
net spindle-corrected lincurve.0.out => hm2_[HOSTMOT2](BOARD).0.pwmgen.00.value
Now, only the spindle can only excute CW rotation and no CCW rotation. Is it because of the negative sign in spindle.0.speed-out?
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19 May 2021 18:40 #209535
by PCW
Replied by PCW on topic Mesa 7i96 to spindle FWD/REV control
Does your lincurve data include negative values?
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19 May 2021 20:05 - 19 May 2021 20:31 #209543
by mhd325ic
Replied by mhd325ic on topic Mesa 7i96 to spindle FWD/REV control
no， it is only in the rang of 0 to 2500. Can we setup in the way so that only the the absolute value go through the lincurve lookup table?
Last edit: 19 May 2021 20:31 by mhd325ic.
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19 May 2021 22:33 #209561
by andypugh
It would be simpler to extend the lincurve into the negative directions. And are you sure that the curve is the same shape in reverse?
Another option might be to close the loop, and use PID.
Replied by andypugh on topic Mesa 7i96 to spindle FWD/REV control
no， it is only in the rang of 0 to 2500. Can we setup in the way so that only the the absolute value go through the lincurve lookup table?
It would be simpler to extend the lincurve into the negative directions. And are you sure that the curve is the same shape in reverse?
Another option might be to close the loop, and use PID.
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20 May 2021 00:53 #209590
by mhd325ic
Replied by mhd325ic on topic Mesa 7i96 to spindle FWD/REV control
I used 12 points in the lincurve for the positive part. I guess that I need to squeeze it into 8 points in order to mirror to the negative side under the constraint of 16 points in lincurve. I will give it a try tomorrow.
Close the loop is an ultimate solution for sure. I will live with lincurve for a while until I figure out how to fit an encoder to my spindle
Close the loop is an ultimate solution for sure. I will live with lincurve for a while until I figure out how to fit an encoder to my spindle
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20 May 2021 16:29 #209663
by mhd325ic
Replied by mhd325ic on topic Mesa 7i96 to spindle FWD/REV control
Hi Andy,
I did mirror the lincurve into the negative direction. Now everything works like charm. Thanks for the helps from everybody!
BTW, what is the multi-element desgined for in lincurve? I got confused because lincurve is a 1D mapping function, say X->Y. How could you extend it into multidimensional linear interpolation.
I did mirror the lincurve into the negative direction. Now everything works like charm. Thanks for the helps from everybody!
BTW, what is the multi-element desgined for in lincurve? I got confused because lincurve is a 1D mapping function, say X->Y. How could you extend it into multidimensional linear interpolation.
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21 May 2021 18:27 #209773
by andypugh
Like all the other HAL components, if you want more than one, you load them all at the same time. But they are independent instances.
I have VBA code that does it in Excel. Let me go to the other computer...
Replied by andypugh on topic Mesa 7i96 to spindle FWD/REV control
BTW, what is the multi-element desgined for in lincurve?
Like all the other HAL components, if you want more than one, you load them all at the same time. But they are independent instances.
That would be a new component. Entirely do-able but pretty painful to put the numbers in to in HAL.How could you extend it into multidimensional linear interpolation.
I have VBA code that does it in Excel. Let me go to the other computer...
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