Re: [Emc-users] Help with PWM spindle control

[andy p. <bod...@gm...>]

On 12 March 2011 16:18, Tony Zampini <zam...@co...> wrote:

> addf pwmgen.make-pulses base-thread
> addf pwmgen.update servo-thread
> net spindle-cmd <= motion.spindle-speed-out => pwmgen.0.value
> net spindle-enable <= motion.spindle-on => pwmgen.0.enable
> net spindle-pwm <= pwmgen.0.pwm
> setp pwmgen.0.pwm-freq 10.0
> setp pwmgen.0.scale 4000.0
> setp pwmgen.0.offset -700.0
> net spindle-cw <= motion.spindle-forward

> setp parport.0.pin-01-out-invert 1
> net spindle-pwm => parport.0.pin-01-out

That ought to be enough.
I am a little surprised to see that the output is being inverted, so
that 0 spindle speed will give 5V.

I think the problem is the offset. You would need (spindle/4000) - 700
to be > 0 for any actual PWM.

So, M3 S2802000 should give you a 50% duty cycle :-)

I would suggest setting the offset to  zero and removing the pin-invert.

-- 
atp
"Torque wrenches are for the obedience of fools and the guidance of wise men"