Greetings all; The man 9 encoder page assumes its talking about the software encoder module, not one of the nearly hardware blocks in a mesa card, so there obviously is/are some differences.
One of the things I'd like to do is to implement a delay count after the mesa card outputs an index, of a certain number of edges, in my case up to 240, between the index pulse from the card, and the "index" pulse actually fed to motion. This to function as a phase adjustment between the spindle and an existing thread. This would seem to require that an externally generated reset pulse be fed back to the mesa encoder to reset its index instantly, without depending on motion to reach back and do it. At this point, we need a counter to be reset by the mesa index, so it can start an 8 bit count, which is compared to the desired count, and when they match, give that to motion as the index its looking for. By this means, we could rotate the phase of a thread one edge at a time, which would be 1.5 degrees of rotation per count added or subtracted to the comparison value. It would be handier than sliced bread if this counter were in the mesa firmware because then we might be able to look at that "raw" value, and trigger our regenerated index without loading up the limited iron in the pi's toolbox. In software, it would have a spindle speed limit, 240 edges per turn at 4 turns a second is 960 which is probably overruning our 1khz effective sample rate, meaning we'd be missing counts. But if its missed, the spindle will simply make another rev before the z motion is started. So 200 revs should be the max we ask this bit of rube goldbergury to work well. But we're obviously talking bigger threads too, not the sub 8mm stuff that strains my mill. Absolutely none of these details is well enough documented in the mesa docs, well enough to be able to work out the feasibility of such a contraption. Where can I improve my knowledge in this regard? Thanks for reading my wee hours of the morning ramblings. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
