Thank you very much Charles, i use the ehrpwm0a pin and now it works flawlessly :)
again thanks for your support Am Freitag, 23. September 2016 18:18:26 UTC+2 schrieb Charles Steinkuehler: > > ehrpwm0B is on P9 pin 29: MISO on the CRAMPS board (P503 pin 2) > > ehrpwm0A is on P9 pin 31: SCK on the CRAMPS board (P503 pin 4) > > This may help: > > > https://github.com/cdsteinkuehler/beaglebone-black-pinmux/blob/hal_pru_generic/pinmux.ods > > > On 9/23/2016 11:04 AM, Sag ich Dir nich wrote: > > so i searched for the pin of "ehrpwm0a" and "ehrpwm0b" in the shematics > of the > > board but only found "ehrpwm1a" "ehrpwm1b" "ehrpwm2a" and "ehrpwm2b". > > the last page of that shematics where p503 is, does not say anything to > me, so i > > searched in the internet and got up with "p9.22" for "ehrpwm0a" but in > the > > shematics it is labeled with UART2_RXD | FET6 > > > > Am Freitag, 23. September 2016 17:24:34 UTC+2 schrieb Charles > Steinkuehler: > > > > 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> < > 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+...@googlegroups.com <javascript:> > > > <mailto:machinekit+unsubscr...@googlegroups.com <javascript:> > <javascript:>>. > > > Visit this group at https://groups.google.com/group/machinekit > > <https://groups.google.com/group/machinekit>. > > > For more options, visit https://groups.google.com/d/optout > > <https://groups.google.com/d/optout>. > > > > > > > > > -- > > 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+...@googlegroups.com <javascript:> > > <mailto:machinekit+unsubscr...@googlegroups.com <javascript:>>. > > Visit this group at https://groups.google.com/group/machinekit. > > For more options, visit https://groups.google.com/d/optout. > > > > > -- > 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. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
