Andy Holcomb wrote: > How would I implement this? To be more specific which pin on the LPT > port would I attach the wire to?
Any pin that is an input and isn't already in use. > Would I need to have the other leg of > the switch tied to ground or 5 volts? EIther one. If you tie the other end of the switch to +5, then closing the switch will pull the parport pin high. You need something else to pull it low when the switch is open. If you tie the other end of the switch to ground, then closing it will pull the parport pin low. Since A) many parports already have pullups, and B) there isn't a convenient source of +5 on the parport, its usually easier to hook a switch between the parport pin and ground. The above is NOT an EMC specific issue. How to hook a button to a parport is basic fundamental knowledge for using a PC to control anything. This information is on the web - for example http://www.epanorama.net/circuits/parallel_output.html Inputs are addressed in the section "Input Circuits" about 3/4 of the way down the page. Electrically, connecting a pushbutton or toggle switch is no different than connecting a limit or home switch. > In which config file will I need > to set this up In your HAL file. You have a choice - you can add custom HAL stuff to your existing file (I assume that is a copy of one of the sample configs) or you can put your stuff in another file and invoke it from the ini file. > and how would I do that? Lots of possibilities. You could get fancy and use classicladder to make a latching pushbutton (push button A to pause, button B to resume). You could do the same thing with the HAL flipflop component (simpler - see "man flipflop"). You could use a toggle switch instead of a pushbutton - that means no latching is needed at all. A couple of detailed examples: 1) You are using a toggle switch, and wired it to pin 10 of the parport. The switch is wired from pin 10 to ground, then when you flip it ON, pin 10 goes low. Add this to your hal file: # when external PAUSE switch is on (input low), pause the # machine using feedhold input net feedhold parport.0.pin-10-in-not motion.feed-hold 2) You have two buttons. PAUSE is connected to parport pin 10, and RESUME is connected to parport pin 11. Both are active low (pressing the button makes the pin on the parport go low). Use a flipflop to do the latching: # need a flip-flop to latch the state of feedhold loadrt flipflop count=1 addf flipflop.0 servo-thread # connect the flipflop output to the motion controller # so motion will stop when the flipflop is set TRUE net feedhold flipflop.0.out motion.feed-hold # the PAUSE button should set the flipflop net pause-button parport.0.pin-10-in-not flipflop.0.set # and the RESUME button should reset it net resume-button parport.0.pin-11-in-not flipflop.0.reset I sincerely hope you do NOT just copy these examples and use them. To get the most out of EMC and HAL, you should understand what it is doing. The HAL code above is not very complicated, and it is commented. If you read it and understand it, you have taken the first step from "machine user" to "machine builder". If you aren't willing to take that step, then you are stuck using the stock configuration. The EMC2 Integrator Manual is the "bible" for machine builders. http://www.linuxcnc.org/docs/2.1/EMC2_Integrator_Manual.pdf Regards, John Kasunich ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
