On Sunday 12 March 2017 23:54:49 Jon Elson wrote: > Got some rotary switches in, and built up a palm-sized MPG > pendant for my Bridgeport today. > I built my first pendant using a big Fanuc MPG that John > Kasunich gave me at a codefest/CNC meeting in about 2007. > When I built a second one, I used an encoder very similar to > the ones from MP Jones and found I could do touching-off > with a paper feeler if I held the pendant in one hand and > operated the MPG with my thumb. My first version was not > set up so that was very easy to do. So, I just made a new > one that allows me to do that. > > See http://pico-systems.com/pendant.html > for pictures of my first and 2nd versions. The one I just > built with the MP Jones encoder is VERY similar to the 2nd > picture. > You can hold it in one hand, press the enable button with > your index finger and jog with your thumb. > > Jon > The switches I wound up using for the enables are much higher force switches than I would have liked. At least a pound to make them click.
So I will have a timedelay in the code as a time to disable the wheels. When the switch is depressed to the click point, it will steer the wheels A=B=on signal to an updown, input controlled by the wheels turn direction to drive the count.up and count.down inputs. The updown is restricted to a 0-7 range, and decoded by a bitslicer whose 3 output lines are the sel's for a mux8 which has the jog size setp'd to its 8 inputs. When the button is released the timedelay eventually times out and disables the wheel. Currently set for a 10 second timeout. More time is obtained by pressing the button again w/o moving the wheel. With the range clamped, for largest jog, just press button & spin cw, back to minimum, press button and spin ccw. I think each of us likely has his own take on how a wheel should work, and my back, already tired from the housework (but the microwave is fixed hoooooraayyy!) is limiting my time at the machine as that forces me to stand and lots of walking around it, so my code isn't working yet because I tested it with halshow without either the wheels or the switches hooked up. So I have some logic that needs inverted and the timedelay re-routed. I suspect my code is 3x the complexity of that for a single wheel pendent. And I also suspect that the wheel reading parts may have to be moved to the faster servo-thread else counts might be missed at a 100hz sample rate. The wheel can be turned faster than one rev/second. That, or speed up my "jog-thread" to 500hz, as cpu loading doesn't seem to be growing that much with a 100hz thread. Full opengl video would help also as the halmeter response is noticeably slow. But my questions on that to the debian-arm list have been ignored, twice now. Does anyone here have a better video drive set up and working on a pi with the jessie install as base, kept uptodate daily? Thanks everybody 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> ------------------------------------------------------------------------------ Announcing the Oxford Dictionaries API! The API offers world-renowned dictionary content that is easy and intuitive to access. Sign up for an account today to start using our lexical data to power your apps and projects. Get started today and enter our developer competition. http://sdm.link/oxford _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
