# Monitoring loop. Begins at Klipper start.
[delayed_gcode CHECK_ALL_FANS]
initial_duration: 1
gcode:
    HOTEND_FAN_CHECK
    UPDATE_DELAYED_GCODE ID=CHECK_ALL_FANS DURATION=3

# Change min_rpm and max_consecutive_stops to your desired values.
[gcode_macro HOTEND_FAN_CHECK]
variable_he_stop_count: 0
gcode:
    {% set min_rpm = 3000|float %}
    {% set max_consecutive_stops = 3 %}
    {% set rpm = printer['heater_fan hotend_fan'].rpm|float %}
    {% set he_target = printer[printer.toolhead.extruder].target|float %}
    {% set he_temp = printer[printer.toolhead.extruder].temperature|float %}
    {% set fan_on_temp = printer.configfile.settings['heater_fan hotend_fan'].heater_temp|float %}
    {% set he_stop_count = printer["gcode_macro HOTEND_FAN_CHECK"].he_stop_count|int %}

    {% if (he_target >= fan_on_temp) and (rpm < min_rpm) and (he_temp >= fan_on_temp) %}
        SET_GCODE_VARIABLE MACRO=HOTEND_FAN_CHECK VARIABLE=he_stop_count VALUE={he_stop_count + 1}
        RESPOND PREFIX="HOTEND FAN CHECK:" MSG="Hotend fan stoppage detected ({he_stop_count+1}/{max_consecutive_stops})."
        {% if printer["gcode_macro HOTEND_FAN_CHECK"].he_stop_count|int >= max_consecutive_stops-1 %}
            M400
            FAN_STOPPAGE_ROUTINE
        {% endif %}
    {% else %}
        SET_GCODE_VARIABLE MACRO=HOTEND_FAN_CHECK VARIABLE=he_stop_count VALUE=0
    {% endif %}

# Insert the gcode that you want to run when a fan stoppage is detected.
# This runs every ~3 seconds until the stop conditions are cleared.
[gcode_macro FAN_STOPPAGE_ROUTINE]
gcode:
    # If not already paused
    {% if printer['pause_resume'].is_paused|int == 0 %}
        M117 !!FAN STOPPAGE!!
        RESPOND PREFIX="FAN CHECK:" MSG="Fan stoppage detected. Pausing print."
        PAUSE
        SET_HEATER_TEMPERATURE HEATER=extruder TARGET=0 # Turn off the hotend. 
    {% endif %}