On 10/17/2017 3:14 PM, Pauluzs wrote: > > There are some questions i run into: > Can the beaglebone/machinekit even keep up with this amount of pwm pins? > Should i use the pru stepgen code? (stepgen does not seem to support 3 > phase)
You'd need to code a 3-phase stepgen. > Should i use the pru pwm code? I wouldn't. > Use the bldc component with standard writes? This won't work well on the BBB, the ARM can't handle a high-speed base-thread, which is why the PRU is used instead. > Or use the bldc component with pru_pwm? Maybe, but I don't think you'll get the performance you want (see below). > Usefull thoughts or comments are most welcome, I would only recommend using the BBB and PRUs if you are driving the BLDC as a 3-phase stepper, but since you are wanting a bunch of PWM channels, it sounds like you want a "proper" drive for the BLDC. The PRU is well suited to tasks on the order of several uS, but if you're wanting a 20 KHz PWM rate that means you only have 20-50 or so discrete PWM steps (without radically re-writing the PRU code). You could use the hardware timers on the BBB to run some of your PWM channels, but there aren't enough for all your motors. I'd recommend using FPGA hardware (either x86 + Mesa hardware or one of the ARM SoC+FPGA boards) for your application. -- Charles Steinkuehler [email protected] -- 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.
