On 01/03/2014 11:03 AM, Jared Turner wrote: > > I’m using a BBB with LinuxCNC to retrofit an old CNC mill. I have all > of the stepper motors working, but I would like to add programmatic > control of the spindle. The motor drive uses an analog signal, so I > bought a digital pot so the speed can be controlled digitally. How do > I add support for this with the existing HAL code? I want to retain > the extruder control so I can use the mill for a 3d printer. I have a > link to the digital pot’s datasheet below. Thanks for the help.
Spindle drivers come in different forms, but often are VFDs or SCR DC. VFDs are often controlled with a PWM signal going to an opto-coupler. An example is here: http://wiki.linuxcnc.org/cgi-bin/wiki.pl?VFD_Digital/Analog_Interface also try searching 'vfd' on the wiki: http://wiki.linuxcnc.org/cgi-bin/wiki.pl Or with SCR or KBIC type drivers, again a PWM and opto-coupler can be used: http://www.wallacecompany.com/machine_shop/kbic/ The SCR drivers usually have a floating input at high voltage, so be careful. http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Closed_Loop_Spindle_Speed_Control http://www.cnc4pc.com/Store/osc/index.php?cPath=25&osCsid=4ee7c2af33a2df353290adab83b731b7 http://linuxcnc.org/docs/html/man/man9/pwmgen.9.html -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
