I'm aware that the PRU's are separate from the OS But it was my understanding that you can set the OS to use just one core (for the most part)
https://stackoverflow.com/questions/13583146/whole-one-core-dedicated-to-single-process https://superuser.com/questions/1082194/assign-an-individual-core-to-a-process so for example use "isolcpus=1,2,3" which just leaves core 0 free for the OS but reserves the other 3 core's for a dedicated process. (there's also the irqaffinity option) then use taskset -a -p 1 PID to allocate a process to a specific core. I may have up to 4 steppers for x, y, z and possibly another 2 if I try to do 5 axis in the future. plus SPI for the stepper drivers and lots of end stops so I was considering testing out the latency on some SPI to RS485 interfaces to hook everything up. On Wednesday, December 20, 2017 at 6:08:24 AM UTC, Rob M wrote: > > > > On Wednesday, December 20, 2017 at 4:38:19 PM UTC+11, Rob M wrote: >> >> >> >> The BBB PRU's are separate from the underlying OS. >> >> The cores of the RPi or any other multi core chip, (as for as I am aware) >> can't be separated from the OS. >> >> I'd run a BBB any day of the week over a RPi. >> >> The way I have my BBB setup allows me to have 35 gpio's plus I2c and that >> is with HDMI. I've made a custom cape and 2 connecting daughter boards that >> I have setup with 12 Outputs & 5 inputs on one board and 13 inputs and 4 >> outputs on the other. Similar to a PC with 2 Parallel ports. The extra gpio >> is used to control the OE of each board. The boards also do the conversion >> from 3.3v to 5v and 5v to 3.3v. >> >> The PRUs are great for step generation and reading a MPG type quadrature >> encoder. >> >> If you want to run the BBB headless that will allow for a few extra >> GPIO's. I think from memory my max velocity is 4800mm/minute which is kind >> of scary fast one a BF20/G0704 Benchtop mill. >> >> I know the RPi is cheaper, has more memory and better graphics than the >> BBB, but the fact that you can have hardware step-dir generation without >> any extra hardware with the BBB is a winner. And personally I really don't >> see an issue with the BBB graphics when running axis. >> >> Personally the BBB rocks and actually prefer it over a x86 platform for >> running my mill. >> >> Anyway that just my opinion...and as they say opinions are >> like............ everyone has one. >> >> Keeping asking questions, you'll get more answers and eventually work out >> which option is best for your situation. >> > -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
