The pull-up resistor would go between the FET output and the 5V power rail.
But I'm not sure you should use a FET output. The FETs were not designed to be fast, and have a pretty significant turn on/off delay (this is intentional, to limit dI/dT caused voltage spikes). I'd suggest using ehrpwm0A or ehrpwm0B, both of which are available on the SPI expansion header of the CRAMPS board (P503). The 3.3V BBB output should be able to directly drive the Pololu H-Bridge input, which accepts logic levels down to 1.8V. On 9/23/2016 10:02 AM, Sag ich Dir nich wrote: > while i read myself into creating python components, do you mean i should put > the resistor between the FET + output (which is going into the pwm pin on the > motor controller) and the extruder power input (p405)? > > Am Freitag, 23. September 2016 15:57:40 UTC+2 schrieb Charles Steinkuehler: > > On 9/23/2016 8:39 AM, Sag ich Dir nich wrote: > > thank you, the motor controller i use is the > > > > Pololu G2 High-Power Motor Driver 24v21 > > > > https://www.pololu.com/product/2995 > <https://www.pololu.com/product/2995> > > That is pretty much just a raw H-Bridge driver. The PWM output from > the PRU will not be nearly fast enough to provide smooth operation. > > I suggest you use one of the BBB's hardware PWM channels running at > about 20 KHz (the PWM frequency recommended by Pololu). While the PWM > pulses need to be generated quickly, updates to the PWM can happen > slowly. I suggest you write a simple user-mode Python HAL component > and use one of the available libraries to drive the hardware PWM logic. > > -- > Charles Steinkuehler > cha...@steinkuehler.net <javascript:> > > -- > 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 machinekit+unsubscr...@googlegroups.com > <mailto:machinekit+unsubscr...@googlegroups.com>. > Visit this group at https://groups.google.com/group/machinekit. > For more options, visit https://groups.google.com/d/optout. > -- Charles Steinkuehler char...@steinkuehler.net -- 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 machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
