Yes, you are right about the PRU's I have two Beagles here on my desk I thought about using the PRUs but I want my code to be portable so I avoid using them. Instead I do that kind of work with ARM Cortex-M. This preserves the possibility to upgrade the
There ARM M is tiny and dirt cheap and is very good for real-time work. I have a robot with four motors and encoders and get 44,000 interrupts per second and much better real time latencies then from any Linux based solution on any platform. My solution for robot control is a hierarchy with ARM M for the lowest level, then Raspberry Pi 3 connected by high speed serial. Finally the Pi 3 uses WiFi to connect to server class 16-core Xeon That said I always try to use the bigger computer for software development if I can usually I can at least start there until I need to test on real hardware Back to machine tools - Why bother trying to save power and space. The milling machine already need AC mains power and weights a LOT. What does one save by using a micro sized controller very an ATX save mainboard? Why can't LinuxCNC run faster on the BBB then on a 10 years old PC? A computer is not a CPU. It has also a memory and I/O subsystem. Also you can't compare clocks. What mattress how mach work is done per clock. The old PC does 2 or 4 times as much per clock and the BBB/ So your 10 year old 1.7Ghz PC is kind of like owning a 4GHz BBB, if such a thing could exist. Then you compare the graphic abilities and the old PC wins by a huge amount. The BBB is great if you need it's small size and low power. And it's the wrong thing to use if you don't have need to save size and power. I've got several project going and those running off batteries all use ARM M and A type. On Sat, Oct 7, 2017 at 7:00 PM, John Dammeyer <jo...@autoartisans.com> wrote: > Hi Chris, > Thanks for your comments. > > > > I don't know why people like to use these 1GHz ARM boards for machine > > controllers. > > I use them for projects that run on batteries but if you have AC mains > > power available > > go with a bigger computer. > > > > You can stay with Machine kit but I just don't see why so many people > like > > the low > > powered ARM boards. > > > > The Beagle is in a different class from the Raspberry Pi and Arduino > modules. The dual PRU's allow it to do things that outshine the LinuxCNC > systems from 20 years ago running on Pentium 33 size machines. The nice > thing about them is they are small. A small 1GHz 32 bit PC in the tiny > brick format costs into the hundreds of dollars. > > But that's also why I asked. Comparisons that I've done with a Pi3 and a > BeagleBone Black show for normal graphics GUI and even compiling programs > with Lazaras (Delphi Pascal) that the Beagle is about half the speed but > then the Pi3 has a dual processor core. Probably still not fast enough to > do the real time stuff for Linux. > > But it does be the question doesn't it? If Linux could run real time on > much slower PCs 10 years ago, why can't it run on the much faster with more > memory Beagles? > > Has LinuxCNC really changed that much? > > As I mentioned in the reply to Andy. I'm hoping to start a conversation > with people who have used both and perhaps even Mach3. > > John > > > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
