How to get the Controller fan to turn on at power up?

Basic Information:

Printer Model: RatRig v-core 3.0
MCU / Printerboard: BTT Octopus v1.1
klippy.logklippy.log (1.2 MB)

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Describe your issue:

…I want the controller fan to come on at power up. Maybe I’m missing something but seems like that should be SOP? I tried this override, which put another fan under “misc” in the dashboard.

[controller_fan my_controller_fan]
pin: PC8
max_power: 1.0
shutdown_speed: 0
cycle_time: 0.010
hardware_pwm: False
kick_start_time: 0.100
off_below: 0.0
#   See the "fan" section for a description of the above parameters.
fan_speed: 1.0
#   The fan speed (expressed as a value from 0.0 to 1.0) that the fan
#   will be set to when a heater or stepper driver is active.
#   The default is 1.0
idle_timeout: 30
#   The amount of time (in seconds) after a stepper driver or heater
#   was active and the fan should be kept running. The default
#   is 30 seconds.
idle_speed: 1.0
#   The fan speed (expressed as a value from 0.0 to 1.0) that the fan
#   will be set to when a heater or stepper driver was active and
#   before the idle_timeout is reached. The default is fan_speed.
heater: extruder
stepper: stepper_x, stepper_y, stepper_z, stepper_z1, stepper_z2
#   Name of the config section defining the heater/stepper that this fan
#   is associated with. If a comma separated list of heater/stepper names
#   is provided here, then the fan will be enabled when any of the given
#   heaters/steppers are enabled. The default heater is "extruder", the
#   default stepper is all of them.

Does not work with controller_fan as this setting is bound to the criteria as described.

Use a generic fan and pull it up either with a delayed gcode or a static pin.

1 Like

do you want to enable the pins at printer mainboard startup?
if so u can add the pin ( PC8 in your case ) here at the “gpio pins to set at micro-controller startup”, recompile the firmware and reflash it


/edit: if you are using a skr2 board, also enable the PC13 pin in the “gpio pins to set at micro-controller startup”, in your example: PC13, PC8 - “gpio pins to set at micro-controller startup” is a comma seperated list

I have a similar situation, I have one fan that sits over my electronics and want to keep it at an idle speed to keep the pi cool but also hit active speed when my motor drivers are active. The current way the controller fan works is that it only stays in the idle speed for however long you set the timer for. I made the option of keeping it going by adding in a -1 value that would disable the timeout feature. This means that it will run at active speed when called for but any other time it will be at the idle speed including on start up.

I made a pull request on this feature so we will see if it gets adopted.