Peter Restall wrote: >Afternoon All, > >This is my first EMC Users post (first mailing list in a while actually), so >please be gentle with any etiquette misdemeanors ! > > The nerve! :)
>[snip] >So, my question for the time being is, are the parallel port signals (ie. the >waveform/timing diagrams) documented anywhere ? > Yes, it should be in the manuals. I don't know if all the low level stuff is in the PDF manual, but you should find it all on the linuxcnc.org website: <http://www.linuxcnc.org/docview/html/> HAL tutorial here: <http://www.linuxcnc.org/docview/html//hal_tutorial.html> (note: some screenshots are a bit out of date) >For instance, are the axis >step signals sent as pulses (ie. step the motor once per low-high transition), >or are they flat (ie. keep stepping the motor until the signal goes low) ? >I've seen the StepConf documentation - which is the closest I've found - but >that doesn't really explain a lot (it's more end-user oriented). > > Note that you have options that are not step/dir. You can do PWM+direction or up/down PWM for example. Making a driver for a (smallish) servo may be easier than a stepper, since you need half the electronics (one H-bridge instead of two). There is the added complexity of encoders, but those are pretty simple to hook up - you just need more I/Os. If you decide you need some type of output that EMC2 doesn't already have, you can write a component to generate it. EMC2 is separated into several layers, and the motion controller doesn't care how the lower levels get the motors to move. You can use PWM on one axis, step/dir on another, and analog on another, and the motion controller will still be happy (as long as all the motors keep up). >I'm sure I will have more questions, especially around timing, so if there is >a source on the 'net with this sort of low-level detail that I haven't seen >yet, I'd appreciate a link. It's either that or you're going to get sick of >my constant e-mails pretty quickly...! > > <http://cvs.linuxcnc.org/> has all the timing info you need, if you can read C :) HAL components like the step and PWM generators are in the directory emc2/src/hal/components/ - Steve ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
