4028 fan PWM control shutdown MCU
Hi! Yesterday i connected my 4028 fan to control it with PWM signal. I used this tutorial (https://os.ratrig.com/docs/guides/4028/) and because the fan was still working on 0% i had to connect GND from step-down converter to heater 1 - output on mainboard and add enable_pin to the fan section in printer config. The problem is that i keep getting errors in random moments while printing but i realised that it happens on layers when the part cooling fan has to be turned on so I suppose that it causes problems with mcu connection. For example i made one print without print cooling and it went with no issues. The same print with cooling ends up with an error.
4 Replies
exotic-emerald•2y ago
Don't cut power to the step-down, cut power to the fan.. step-downs can cause a brief spike and need a sec to regulate, so switching it off and on repeatedly isn't healthy
or rather, GND
Connect only the power output of the stepdown to the + of the fan, and wire fan GND directly to the heater port. Stepdown input still needs + and -, of course.
harsh-harlequin•2y ago
Okay so + and - from PSU to step_down , + from step-down to the Fan and - from heater port directly to the fan?
exotic-emerald•2y ago
Yep.. then define the - heater port pin as the enable pin.
harsh-harlequin•2y ago
Now everything works fine, thank you for quick response.