On Wed, 2009-06-03 at 18:22 +1000, Erik Christiansen wrote: > On Tue, Jun 02, 2009 at 08:04:00PM +0200, Michael Buesch wrote: > > The AVR certainly is good enough for non timecritical tasks like tool > > changer I/O. > > A tool changer looks like an event-driven application, to me. I don't > know if this site is then of any interest: > > http://github.com/geekscape/Aiko/tree/master > > Admittedly, if I ever reach the point where I'm adding a tool changer, > I'd probably go with the state machines which I've used for quarter of a > century. (Telecommunications products often use many intercommunicating > state machines to rapidly process inputs in a stateful manner, in real > time. The language used is clumsily named "Specification and Description > Language", but is very powerful.) > > Erik
I prefer to have EMC2 do as much as it can. If I understand the term "state" correctly, I would just use parport I/O and handle the logic in a hal component. For the rest of the machine, I've gotten away with software signals, but in this particular situation I need to have a fast hardware PWM signal. I could use a Pluto-P or something similar, but for just one signal, it's over-kill. Ideally, I would have a $20 board with an SPI input and a PWM output, which I could use where ever it's needed. Then not worry about, when I upgrade the rest of the machine to a grown-up I/O controller. This ST L99H01 seems to fill the bill: http://www.rutronik.com/index.php?id=939 but I don't know if they are available yet. A micro-controller can also be a cheap solution, but the problem is that they can also do a lot more, so it's tempting to add more features and lose the original intent. Another rambling thought, is that you could have these $20 micro-controller boards that you plug into a socket and turn them into whatever function you need at the time. I think this is what the Arduino is about. I suppose this is just a matter of creating an EMC2 "hardware comp" application. The card could have a few EMC2 terminals that connect to a parport (for SPI), a few machine side terminals, then a USB port. You plug the board into the PC's USB port, a window pops up, you press a button to select the function you need, and presto, you have an ADC input, fast PWM output, fast encoder input, or whatever you need that the parport can't normally do. The problem here is that there is no good way to handle all the machine side signal conditioning and still keep things simple. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ OpenSolaris 2009.06 is a cutting edge operating system for enterprises looking to deploy the next generation of Solaris that includes the latest innovations from Sun and the OpenSource community. Download a copy and enjoy capabilities such as Networking, Storage and Virtualization. Go to: http://p.sf.net/sfu/opensolaris-get _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users