LDO Nitehawk MCU template and tachometer proper integration

config/hardware/fans/hotend_fan_tachometer.cfg

@@ -0,0 +1,14 @@
+[gcode_macro _USER_VARIABLES]
+variable_hotend_fan_tach_enabled: True
+gcode:
+
+[heater_fan hotend_fan]
+pin: E_FAN
+max_power: 1.0
+kick_start_time: 0.100
+heater: extruder
+heater_temp: 50.0
+tachometer_pin: E_FAN_TACHO
+
+# And we also include the tachometer check macros from here
+[include ../../../macros/helpers/tachometer_check.cfg]

config/hardware/fans/part_fan_tachometer.cfg

@@ -0,0 +1,12 @@
+[gcode_macro _USER_VARIABLES]
+variable_part_fan_tach_enabled: True
+gcode:
+
+[fan]
+pin: PART_FAN
+kick_start_time: 0.100
+cycle_time: 0.010
+tachometer_pin: PART_FAN_TACHO
+
+# And we also include the tachometer check macros from here
+[include ../../../macros/helpers/tachometer_check.cfg]

docs/pinout.md

@@ -57,7 +57,9 @@ Here is a list of all the "Frix-x names" available to use in your own board_pins
 #### Fans
 
   - `E_FAN`: hotend fan. This fan should stay at 100% whenever the hotend is hot, so a PWM capable pin is not mandatory
+  - `E_FAN_TACHO`: tachometer of the hotend fan, optional and used to validate that the fan is spinning as a safety feature
   - `PART_FAN`: part fan used during the print. This pin should be a PWM capable pin to allow modulation of the fan speed
+  - `PART_FAN_TACHO`: tachometer of the part fan, optional and used to validate that the fan is spinning as a safety feature
   - `EXHAUST_FAN`: for an exhaust filter (such as the Voron basic exhaust). This pin should be a PWM capable pin to allow modulation of the fan speed
   - `FILTER_FAN`: for a filter (such as a Nevermore filter). This pin should be a PWM capable pin to allow modulation of the fan speed
   - `CONTROLLER_FAN`: to cool down your MCUs or electronic bay

macros/base/cancel_print.cfg

@@ -13,6 +13,7 @@ gcode:
     {% set bed_mesh_enabled = printer["gcode_macro _USER_VARIABLES"].bed_mesh_enabled %}
     {% set filament_sensor_enabled = printer["gcode_macro _USER_VARIABLES"].filament_sensor_enabled %}
     {% set filter_default_time = printer["gcode_macro _USER_VARIABLES"].filter_default_time_on_end_print|default(600)|int %}
+    {% set hotend_fan_tach_enabled = printer["gcode_macro _USER_VARIABLES"].hotend_fan_tach_enabled %}
 
     PARK
 
@@ -33,6 +34,10 @@ gcode:
         SET_HEATER_TEMPERATURE HEATER=extruder TARGET={safe_extruder_temp}
     {% endif %}
 
+    {% if hotend_fan_tach_enabled %}
+        UPDATE_DELAYED_GCODE ID=_BACKGROUND_HOTEND_TACHO_CHECK DURATION=0
+    {% endif %}
+
     M107
     M400
 

macros/base/end_print.cfg

@@ -13,6 +13,7 @@ gcode:
     {% set bed_mesh_enabled = printer["gcode_macro _USER_VARIABLES"].bed_mesh_enabled %}
     {% set filter_default_time = printer["gcode_macro _USER_VARIABLES"].filter_default_time_on_end_print|default(600)|int %}
     {% set filament_sensor_enabled = printer["gcode_macro _USER_VARIABLES"].filament_sensor_enabled %}
+    {% set hotend_fan_tach_enabled = printer["gcode_macro _USER_VARIABLES"].hotend_fan_tach_enabled %}
 
     PARK
 
@@ -33,6 +34,10 @@ gcode:
         SET_HEATER_TEMPERATURE HEATER=extruder TARGET={safe_extruder_temp}
     {% endif %}
 
+    {% if hotend_fan_tach_enabled %}
+        UPDATE_DELAYED_GCODE ID=_BACKGROUND_HOTEND_TACHO_CHECK DURATION=0
+    {% endif %}
+
     M107
     M400
 

macros/base/start_print.cfg

@@ -61,6 +61,8 @@ gcode:
     {% set firmware_retraction_enabled = printer["gcode_macro _USER_VARIABLES"].firmware_retraction_enabled %}
     {% set filter_enabled = printer["gcode_macro _USER_VARIABLES"].filter_enabled %}
     {% set filament_sensor_enabled = printer["gcode_macro _USER_VARIABLES"].filament_sensor_enabled %}
+    {% set part_fan_tach_enabled = printer["gcode_macro _USER_VARIABLES"].part_fan_tach_enabled %}
+    {% set hotend_fan_tach_enabled = printer["gcode_macro _USER_VARIABLES"].hotend_fan_tach_enabled %}
 
     {% if MATERIAL not in printer["gcode_macro _USER_VARIABLES"].material_parameters %}
         RESPOND MSG="Material '{MATERIAL}' is unknown!"
@@ -96,6 +98,19 @@ gcode:
         STOP_FILTER
     {% endif %}
 
+    # If a tachometer is enabled on one of the fans, we check them:
+    #   - It's done only once for the part fan to be sure nothing block it before starting the print
+    #   - And as a safety feature, we start a monitoring loop for the hotend fan (that is automatically stopped at the end of a print)
+    {% if part_fan_tach_enabled %}
+        M106 S255
+        G4 P2000
+        _PART_FAN_CHECK
+        M106 S0
+    {% endif %}
+    {% if hotend_fan_tach_enabled %}
+        UPDATE_DELAYED_GCODE ID=_BACKGROUND_HOTEND_TACHO_CHECK DURATION=1
+    {% endif %}
+
     SET_GCODE_OFFSET Z=0
     M221 S100
     M220 S100

macros/helpers/tachometer_check.cfg

@@ -0,0 +1,44 @@
+## This config file contains macros that are used in conjuction with tacho-enabled hotend and part fans
+
+# Monitoring loop for hotend fan safety check
+[delayed_gcode _BACKGROUND_HOTEND_TACHO_CHECK]
+gcode:
+    _HOTEND_FAN_CHECK
+    UPDATE_DELAYED_GCODE ID=_BACKGROUND_HOTEND_TACHO_CHECK DURATION=3
+
+[gcode_macro _HOTEND_FAN_CHECK]
+description: Check the hotend fan tachometer to verify that it is running effectively
+variable_he_stop_count: 0
+gcode:
+    {% set min_rpm = 1000|float %} # This is a relatively low value adapted to all fans to check that they are effectively running
+    {% 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 MSG="Hotend fan stoppage detected for {(he_stop_count+1)*3}sec (max {max_consecutive_stops*3}sec allowed)"
+        M400
+        {% if printer["gcode_macro _HOTEND_FAN_CHECK"].he_stop_count|int >= max_consecutive_stops-1 %}
+            CANCEL_PRINT
+        {% endif %}
+    {% else %}
+        SET_GCODE_VARIABLE MACRO=_HOTEND_FAN_CHECK VARIABLE=he_stop_count VALUE=0
+    {% endif %}
+
+
+[gcode_macro _PART_FAN_CHECK]
+description: Check the part fan tachometer to verify that it is running effectively
+gcode:
+    {% if printer.fan.rpm is not none %}
+        {% if printer.fan.rpm > 1000 %} # This is a relatively low value adapted to all fans to check that they are effectively running
+            {action_respond_info("Part fan OK!")}
+        {% else %}
+            M400
+            CANCEL_PRINT
+            {action_raise_error("Hotend fan stoppage detected, print was canceled!")}
+        {% endif %}
+    {% endif %}

user_templates/mcu_defaults/main/BTT_SKR_3.cfg

@@ -1,3 +1,4 @@
+
 #-------------------------------------#
 #### BTT SKR3 definition ####
 #-------------------------------------#

user_templates/mcu_defaults/main/BTT_SKR_Pro_V1.2.cfg

@@ -1,3 +1,4 @@
+
 #----------------------------------------#
 #### BTT SKR Pro v1.2 definition ########
 #----------------------------------------#

user_templates/mcu_defaults/main/MY-OWN-CUSTOM-TEMPLATE.cfg

@@ -37,7 +37,9 @@ aliases:
     E_HEATER=   , E_TEMPERATURE=   ,
     BED_HEATER= , BED_TEMPERATURE= ,
 
-    PART_FAN= , E_FAN= ,
+    PART_FAN=      , E_FAN= ,
+    PART_FAN_TACHO , E_FAN_TACHO ,
+
     CONTROLLER_FAN=        ,
     EXHAUST_FAN=           ,
     FILTER_FAN=            ,