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
Am Donnerstag, 22. September 2016 19:37:19 UTC+2 schrieb Charles
> 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
> > 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
> > and when one axis changed direction, the motor stopped for a few
> > 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
> 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
website: http://www.machinekit.io blog: http://blog.machinekit.io github:
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