On Wednesday 13 April 2016 09:07:26 Dmitry Yurtaev wrote: > On Wed, Apr 13, 2016 at 2:29 PM, andy pugh <[email protected]> wrote: > >> or is it possible to > >> change HOME_SEARCH_VELOCITY at run-time? if so, then it will do > > > > I don't think you can change the homing data at run-time. > > One option might be to choose a different config depending on > > whether absolute position has been lost. > > to know if abs position is good it needs a driver module loaded to ask > a servo amp, so can't do it easily before linuxcnc is up and > running... > but thanks, you gave me another idea. i think i can use existing > halui.joint.n.unhome pins. instead of adding "set-homed" pins maybe it > is easier do the following > > 1. add code which saves "motor_offset" values in position.txt or some > other place. if i'm not mistaken, those values are the sole result of > performing a homing procedure. so if i want persistent home i need to > save those
I envy you, you do have data to save. The average stepper has no microstep index marker, nor is there a way to tally it back to LCNC. However since the driver powers up in a default zero microstep position, would it be possible to add the microstep value as a mod(steps % microsteps) function during homing, and save that? We would then have to decide which way the motor should be microstepped at enable time to place it exactly at the microstep that existed at the homing switch detection. But do this again at position.txt save, saving too the result of the last position it was parked at so we could step the motor back to this position at the next powerup/enable. This would seem to be a step forward toward achieving a home once (theoreticly) operation of a machine that has no handwheels, powering up in the same nominal position, but the driver will whang it to the zero micro-stepped position. The object is to give the driver a few millisecs to stabilize, then step the motor one way or the other to get back to the microstepped position it was in when powered down. Am I making sense? > 2. start up in homed state (new option of combination of values to > existent ones? something akin to HOME_SEARCH_VEL=0..) > 3. unhome if abs position is lost. i have "abs-lost" output pin in the > driver > > adding a new pin to halui brings up too much new code... this should > be much briefer > > /dmitry > > ---------------------------------------------------------------------- >-------- Find and fix application performance issues faster with > Applications Manager Applications Manager provides deep performance > insights into multiple tiers of your business applications. It > resolves application problems quickly and reduces your MTTR. Get your > free trial! > https://ad.doubleclick.net/ddm/clk/302982198;130105516;z > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
