different software times, impossible?

[HenrikOlsson]

So the PIC is what's going to generate the pulses for two step motor drivers and you're trying to implement linear interpolation in the PIC?
Generally what you're looking for is Breshenhams algorithm but your case seems rather specific with one axis always moving the same distance so I don't know.

/Henrik.

[lutherblisset]

if i choose the two pic serially connected solution the two separate quartz can produce an error in time or it will be negligible?

[richard]

it would be relatively easy to to emit 400 cycles of a 50% pw 600uS period wave [x] using a ccp module while toggling another pin at 2 to 12 mS intervals (100-600 pulses) . the pin toggle isr would count down the desired number of [y ] pulses (the period being predetermined) and terminate the ccp output and itself at that point . if a 16 bit timer is used for the isr then the resoution would be reasonable with a 20mhz clk.
you could also look at a PoKeys57 module or an arduino running GRBL.
your description of the problem at hand lacks sufficient detail for me to progress beyond this point , a classic xy problem http://xyproblem.info/

[lutherblisset]

hello richard so its possible to stop the pwm after a fixed time? Maybe its a solution, cause the 400 steps (or always multiply of 400) are fixed, i need only to stop the pwm output after the same time of y, its possible to stop the pwm at the exact point from the software?

[richard]

CPRxCON=12 PWM ON
CPRxCON=0 PWM OFF

You may need to set the CCPx output pin to 0 if the pin idle state is critical

[lutherblisset]

the lowest possible hpwm frequency is 245 hz (for a 4mhz quartz) and 1221hz for a 20mhz quartz, now i have to calculate the frequency of 400 pulses.....

[richard]

try this