Hi, I've become interested in Computer Numeric Control (CNC) machine control. I find there is very little support for the Macintosh platform and many PC programs for the task have a crude user interface so I would like to create a Macintosh CNC application using MacRuby.
CNC programs and motor drivers generally use the LPT parallel port output from a PC in the basic unidirectional mode. Most PC CNC apps do not support PC laptops due to processor sleep logic interfering with stepper motor timing. I would need a similar fast interface on the Mac. I have a Prolific 2305 based USB to IEEE 1284 adapter cable that I would like to use. Mac OS recognizes the device as an "IEEE-1284 Controller" in the USB device tree and I can add a generic print queue for the device, but I don't know how to connect to the device at high speed as the printer controller does. Prolific provides documentation for the simple report protocol for the device. I suspect that an appropriate driver already exists for this device but how would I find it? Thanks, Bob Rice On Jan 17, 2012, at 2:27 PM, Alan Skipp wrote: > Hi folks, > just a quick note (followed by a question) to let you know that my GCD > rendition of ruby 1.9's most used feature – Fibers, is nearing completion. > Code here: > > https://github.com/alskipp/MacrubyFibers > > Currently passes 51 expectations from the fiber spec. 3 failures, all related > to raising exceptions, 2 of which can't be solved just yet as Macruby doesn't > raise LocalJumpError for errant procs. The final test failure I'd like to > fix, so here's the question… > > When executing code on a serial dispatch queue, how can I raise an exception > on the main queue? The following works in an Xcode project: > > Dispatch::Queue.new('serial_queue').async do > Dispatch::Queue.main.sync do > raise "Exception from #{Dispatch::Queue.current}" > end > end > #> Exception from com.apple.main-thread (RuntimeError) > > My assumption is that this works because it is executed within an application > run loop. The same code does not work if invoked directly by Macruby, > presumably due to the lack of an application run loop, Macruby exits before > the Exception can be raised on the main queue, sometimes resulting in a > EXC_BAD_ACCESS crash. > > Is there an alternative approach? > > Cheers, > Al > > > On 10 Jan 2012, at 18:44, Joshua Ballanco wrote: > >> Hey Alan, >> >> Awesome! I haven't had a chance to go through the code in detail, but I like >> the general approach. I'll definitely be looking into this in more detail >> later, but for now I just wanted to let you know that there are specs for >> Ruby 1.9's fibers in the MacRuby repo at 'spec/frozen/library/fiber'. It >> would be interesting to see how many of them pass with your implementation. >> >> Cheers, >> >> Josh >> On Thursday, January 5, 2012 at 10:36 AM, Alan Skipp wrote: >> >>> Hi everyone, >>> I've had a go at implementing Fibers using dispatch queues. The code can be >>> found here: >>> >>> https://gist.github.com/1565393 >>> >>> Inspiration was taken from the following ruby 1.8 Fibers implementation: >>> https://gist.github.com/4631 >>> >>> The implementation of Fiber.yield currently relies upon a hash stored as a >>> class variable. This is hopefully just a temporary solution to get things >>> started. The hash is always accessed through a serial queue (so it should >>> be thread safe) and dead fibers are removed after use. There are a couple >>> of GCD functions that look like they could be used to solve this problem: >>> 'dispatch_queue_set_specific' and 'dispatch_set_context'. Though I'm not >>> sure how to use these from Macruby. If anyone has any experience using >>> either of those GCD functions I'd be interested in learning more. >>> >>> The major omission currently is the lack of a 'transfer' method. I've >>> pondered this quite a bit, but I've yet to come up with a solution. It is >>> quite possible that the way I've written the Fiber class prevents a >>> successful implementation of a 'transfer' method - but I've not given up >>> just yet. If anyone has a cunning plan on how to achieve it, that would be >>> great. >>> >>> I've tested all the examples here: >>> http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html >>> >>> and they all seem to work, plus I've included a few tests in the gist. >>> The test which creates a fiber from Fiber.current, causes macruby to crash, >>> but I don't know why - it doesn't cause a crash when invoked normally >>> outside of minitest. >>> >>> From my limited tests, everything other than the 'transfer' method appears >>> to be working, but feedback would be welcome if you discover any problems. >>> >>> Al >>> _______________________________________________ >>> MacRuby-devel mailing list >>> MacRuby-devel@lists.macosforge.org >>> http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel >> >> _______________________________________________ >> MacRuby-devel mailing list >> MacRuby-devel@lists.macosforge.org >> http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel > > _______________________________________________ > MacRuby-devel mailing list > MacRuby-devel@lists.macosforge.org > http://lists.macosforge.org/mailman/listinfo.cgi/macruby-devel
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