the funny thing i just discovered is, the motor turns even if the machine is powered down, only when i pull the plug of the power supply, the motor shuts off
Am Donnerstag, 22. September 2016 19:37:19 UTC+2 schrieb Charles Steinkuehler: > > On 9/22/2016 12:21 PM, Sag ich Dir nich wrote: > > so now i added a scale (which is maximum rpm) and i can command various > speeds > > but still the motor vibrates. somehow it sounds like it ramps up and > down a bit > > when commanding for example 2000rpm. Noise could probably be, i may > change the > > output to another port (had some coordinate moves with various spindle > speeds > > and when one axis changed direction, the motor stopped for a few > milliseconds), > > is there any pin i can use for pwm that has 5v output on its own? > > The PRU generated PWM output is fairly low frequency. You may need to > increase the PWM frequency (which will decrease the available > resolution) or use one of the hardware PWM outputs. I don't think > there is a HAL driver to talk directly to the BBB's hardware PWM > channels, but for spindle speed a user-mode python script should work > fine. > > There is nothing on the BBB that generates a 5V output (3.3V only), > and no 5V buffered outputs on the CRAMPS boards (just the FET outputs). > > If there is an analog input to your motor control, you could craft a > low-pass filter and the low-speed PWM wouldn't matter that much. > > > what do you mean by "pull-up"? > > A pull-up resistor to 5V. A resistor between the FET output and the > power rail to pull the output high when the FET turns off. > > -- > Charles Steinkuehler > [email protected] <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 [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
