How to activate a PWM Fan with two PWM Ports
Can somebody help me to turn on a 12V PWM Fan via PD14 and PD15? I want to turn the chamber heater fan with 80%
PD14 needs to be 1.0 (on) and PD15 needs to be 0.8 (80%)
Is this possible without a "always on port" ?
8 Replies
thats...not how pwm works?
What are you trying to accomplish?
I have a PWM Fan that should run with 80%
Is it possible to make a PD14 Header run 12V constantly and use PD15 as PWM Signal?
Same like in the documentation but without an available constant on header (they are all in use)
I hope you understand now what I try to achieve
I might think too complicated?
so you have a spare pwm pin, but need 12V from somewhere?
I phrase my question different. For PWM Fan with 3 Pins I need 12V GND and 5V the 5V is PWM Signal right?
How can I achieve this if I just have two PWM Ports (PD14 & PD15) available
ah. I think you can set one of those PD14/15 to just 'on'. Check the klipper docs in the [fan] section
Think yesterday I was just too blind to see. solution is to use
Enable_pin for the main voltage (12V)
Pin: !PD15
cycletime: 0,00004
Fan_speed: 0.8
Enable_pin: PD14
Ah, that'd do it