Using the quite new display_template feature for fans, I have created a fan control for my electronics bay.
It works similar to what is known from today’s PC mainboards, i.e. you set some temperature interpolation points with a corresponding fan power and the template constantly evaluates this and controls the fan depending on the readings of a sensor in the electronics bay.
[display_template FAN_BAY]
text:
# This is the sensor object of the thermistor used to control the fan
{% set temp = printer['temperature_sensor electronics_bay'].temperature %}
# Set the interpolation points here:
{% set points = [
[0, 0.3],
[35, 0.3],
[50, 0.5],
[60, 0.8],
[61, 1.0]
] %}
{% if temp < points[0][0] %}
{ "0.0" | trim }
{% else %}
{% if points|length > 0 %}
{% set value = 0 %}
{% for i in range((points | length) - 1) %}
{% set t1, v1 = points[i] %}
{% set t2, v2 = points[i + 1] %}
{% if t1 <= temp < t2 %}
{% set value = v1 + (temp - t1) * (v2 - v1) / (t2 - t1) %}
{ value | round(3) | trim }
{% endif %}
{% endfor %}
{% if temp >= points[-1][0] %}
{% set value = points[-1][1] %}
{ value | round(3) | trim }
{% endif %}
{% else %}
{ "0.0" | trim }
{% endif %}
{% endif %}
## Cooling Fan of the electronics bay
[fan_generic electronics_bay]
pin: !PD14
max_power: 1
shutdown_speed: 0.0
cycle_time: 0.00004
[temperature_sensor electronics_bay]
sensor_type: Generic 3950
sensor_pin: PF4
# Start the electronics bay fan control
[delayed_gcode _START_BAY_FAN]
initial_duration: 1.
gcode:
SET_FAN_SPEED FAN=electronics_bay TEMPLATE=FAN_BAY
The settings above give a control curve that looks like:
