On Thursday 08 March 2007, John Kasunich wrote: >Andy Holcomb wrote: >> http://littlemachineshop.com/products/product_view.php?ProductID=2938 > >Yes. > >> Can EMC II use a jog wheel yet? >> If so what is required? > >A jog wheel. The ability to count the pulses it makes. Hardware pins >to get the pulses into the system. A few lines of HAL code to hook it > up. > >The wheel you linked to has 40 counts per rev which is typical.
Mmm, the propaganda claims 100. >Assuming you aren't going to spin it faster than 10 revs per second, >that works out to a maximum of 4000 counts per cycle. EMC2 can easily >count that speed in software. (The limit is probably more than twice >that, even on a slow PC.) So all you need is two free general purpose >digital input pins. Parport pins work fine, as do extra inputs from >motenc or mesa cards, or a variety of other general digital input cards >(8255 based, etc). > >The Pico systems boards (USC and UPC) have opto-22 modules on most of >their I/O, which isn't good for encoder signals. However, those boards >have 4 encoder channels. If you have a three axis mill, or a 2 axis >lathe with spindle encoder, you should still have an encoder channel >free to count the jog wheel. Using a hardware counter to count 4000 >counts per second is overkill, but if its there, might as well use it. > >You can do a variety of things with the jogwheel. AXIS provides HAL >pins that can be used to make the wheel control whatever axis is >selected in the GUI. I'm not sure if the other GUIs can do that or not. > You can also select the axis to jog using onscreen buttons with pyVCP, >or real buttons and/or selector switches. You can also select different >scale factors, again with onscreen buttons or real ones. For example, >you could select between 1.000 inch per rev (0.010 per click) and 0.01 >inch per rev (0.0001 per click). > >If you rich and have three wheels, you can hook one to each axis >permanently. Yeah, rich we aren't. There is another product, whose link escapes me ATM, with similar definition, but it can be had for as little as $29 & ship, and has a USB output. No idea how to drag that in and hook it up to hal, but at that price it might be worth a look. Internally it is a quadrature system from the clues given. A solid looking milled alu knob of about 2" diameter, it seems like it would be suitable. I thought I had it bookmarked but cannot find it now. Me, goes off muttering about the old mans stupidity for not bookmarking it. I recall I found it with a google search though, and its available from several dealers who do business on the net at prices ranging up to $59.95 US. It didn't have the spinner, but that's fixable. After all, that is what we do isn't it? >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=DEVD >EV _______________________________________________ >Emc-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/emc-users -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) When the going gets tough, the tough go shopping. ------------------------------------------------------------------------- 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
