Hi guys, I think the other thing that came up was the changing processor environment. The Beagles have been around for a few years now. I've just received the second edition of Derek Molloy's book. Much better than the first. But if I was going to complain about the BBB it would be the Linux moving target more than the hardware. Hardware does tend to be more stable.
I used a prototype development board to develop software for a Motorola 9S12DP512 that is like the original 8 bit MC6809 family but expanded into the pseudo MC6812. http://www.autoartisans.com/rings/M9S12-Eval2.jpg One of these eval boards was mounted in a metal box and ran for a year in an outdoor heated cabinet. The processor has 5 CAN bus channels, I wired in a USB to parallel port interface. The design with the proto board was started at Christmas 2008. Installed end of February 2009. At the same time I also had to design the lamps that the board talked to and the PC software that talked to the M9S12. The project was: http://www.autoartisans.com/rings/YVR-ORings.jpg In the fall, because the proto-boards were no longer available I whipped out custom module in less than a month. With 6 relay drivers, 6 dry contact switch sensing and added an RS485 port. There's also an internal expansion connector which eventually allowed me to add a Real Time clock, MicroSD card reader and Ethernet Module. http://www.autoartisans.com/rings/Assembled9S12-1.JPG Two of those were installed at the end of OCT2009 and ran until the end of April 2010. http://www.autoartisans.com/rings/Barge1a.jpg That was 10 years ago. The processors, even with the sale of Motorola, are still available. For how long I don't know. The IP was bought by my new customer and I've been making these modules and writing software for them ever since. 32K RAM, 512K flash memory in a 64K paged memory map. At some point we may get an End Of Life email. Then the decision is only really for how many extra processors to order. 500? 1000? The development environment only ran on Windows and I'm not even sure it will run on WIN-10. It hasn't been changed or upgraded for 10 years either. Or maybe it's time to look at the ARM family. I believe ST makes a 4 or 5 CAN port ARM processor. It's whether or not there is single step debugging hardware available. The current 9S12 is programmed via the USB port with encrypted files. So that would have to be developed for the ST family of hex files. The modules on the CAN bus (CANopen) are also programmed with encrypted files. Some of the 9S12 software is closely coupled to the paging and 8/16 bit architecture. Changing isn't just a recompile. And to bring this back to LinuxCNC and ARM or other technology. The software environment has to stabilize. A moving target, be it the OS, the IDE, the compiler, hardware etc. doesn't make for stability if the developers spend more time updating just to stay current. I'm still using a DELTA 1939 band saw. It cuts wood. Gets the occasional replacement blade. Tires. Yes it's a simple tool compared to a PC but it does the job. Until we look at the CNC control of the yet again simple milling machines and lathes we won't see stability. And I realize this is not the majority opinion. John > I am not against modern CPU architecture. It's the sandwich design that > makes no sense to me. And lack of simple connection with easy > interchangeable interfaces for DIO and stepper motors drivers. Capes, > hats, and underware are not professional solutions. It's toys on top of > toys for school projects. Might as well put that in Lego plastics. > > If Beaglebone came with a decent PCB design so that companies could make > professional interfaces for it I would be all over that architecture. I > don't see it anywhere. Trouble is that modern designers don't bother to > see what people created with much more limited resources in the 70's and > 80's. S-100 bus would be better than a "sandwich with header connectors". > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
