> > I have been thinking about FPGA for a communication switch, it would be > > possible to get perfect timings. Then ordinary micro controllers could be > > used for implementing the hardware, the approach is similar to the new > > devices with so called Cortex-M-* PRUs but by using SPI, UART or maybe CAN > > it is possible to build more modular and add an insulation barrier. > > > > The new devices with PRU may be a cheaaper solution for machines built in > > very large series. A modular architecture there different special hardware > > drivers could be combined is a better solution then building a lot of > > different mashines. > > > > The Cortex M Costs about $1 or some of them even less. You can buy a > complete system on a PCB with connectors. For under $3 shipping included. > If you need to make something like a switch or control a few motors these > work well. I have several of them. I am using them for motion controller.
Yes I know it very well and also have a few of them. > In terms of "compute power" They are an order of magnitude above an > Arduino. But not even close to a Pi 3 or BBB. This is good enough for one motor probably with plenty margin. > ... > I'm using one of the boards liked to below to control two motors using > PID. I have two PIP loops running and the optical encoder is sending about > 11,000 interrupts per second for each motor. I run the PIP loops and get > commands over a serial ... Similar as I do. > I would not go with an FPGA unless you need very high speed where signals > are in the teen's of megahertz at least, up to GHz. The FPGA is much > harder to program them an ARM Cortex-M. > > If I were building a machine tool controller from scratch I'd run much of > it on a small computer under Linux then I'd get as many of these Cortex-M > chips as required. Each could handle between 2 and 6 axis. There I am heading. The FPGA could give me as many serial communication ports as needed with perfect communication period. Second option is to add a Ethercat slave device on each device. Regards Nicklas Karlsson ------------------------------------------------------------------------------ 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
