smart filament sensor

 i liked this model but i had the wrong sensor. so I edited it 

for my case i had to change two wires before my printer recognised it. (if you only see a dimmed light then you should to

Also i had to paint the wheel black (i used black nailpollish for that :) )
for klipper i wrote some code

for klipper add:

[filament_motion_sensor filament_sensor]
detection_length: 10
extruder: extruder
switch_pin: ^!PE4
pause_on_runout: false
runout_gcode: FILAMENT_ISRUNOUT

and the macros

[gcode_macro FILAMENT_ISRUNOUT]
description: Is called when filament runout is detected by filament_motion_sensor
gcode:
 {% set runout_state = "delay_runout_check" if printer.print_stats.print_duration < 30 else "runout" %}
 {% set runout_state = "not_printing" if printer.idle_timeout.state != "Printing" else "runout" %}
 # {% set runout_state = "nope" if 1 == 2 else "runout" %}
 {% set counter = printer["gcode_macro cfgs"].counter + 1 %}
 SET_GCODE_VARIABLE MACRO=cfgs VARIABLE=counter VALUE='{counter}'
 # { action_respond_info("counter: %i" % (counter)) }
 { action_respond_info("runout state: %s" % (runout_state)) }
 {% if runout_state == "delay_runout_check" %} 
     { action_respond_info("No runout detection first 30 seconds of print duration.") }
 {% elif runout_state == "not_printing" %}
     ## Printer not in printing state
     { action_respond_info("No runout detection as printer is not in printing state.") }
 {% else %}
       {% set breaker = namespace(found=False) %}
       {% if runout_state == "runout" %}
           {% if counter < 4 %}
               UPDATE_DELAYED_GCODE ID=RECHECK_FILAMENT_ISRUNOUT DURATION=5 ; Recheck after XXs duration
               { action_respond_info("Detected possible runout. Recheck runout sensor in 5s.") }
           {% else %}
               SET_GCODE_VARIABLE MACRO=cfgs VARIABLE=counter VALUE='0'
               { action_respond_info("Detected actual runout. Go to filament change position.") }
               M600 ; Go To Filament Change position
              {% set breaker.found = true %}
           {% endif %} 
       {% endif %} 
 {% endif %}

[gcode_macro M600]
gcode:
    SAVE_GCODE_STATE NAME=M600_state
    CLEAR_PAUSE
    PAUSE
    G91
    G1 E-.8 F2700
    G1 Z50 F600
    G90
    G1 X10 Y10 F10000
    G92
    G92 E0  
    RESTORE_GCODE_STATE NAME=M600_state

[delayed_gcode RECHECK_FILAMENT_ISRUNOUT]
gcode:
    {% set rechecks = printer["gcode_macro cfgs"].rechecks %}
    {% set rechecks=rechecks+1 %}
    SET_GCODE_VARIABLE MACRO=cfgs VARIABLE=rechecks VALUE='{rechecks}'
    {% if printer["filament_motion_sensor filament_sensor"].filament_detected == True %}
        { action_respond_info("filament found, total rechecks: %i"  % (rechecks | int)) }
        SET_GCODE_VARIABLE MACRO=cfgs VARIABLE=counter VALUE='0'
    {% else %}
         { action_respond_info("no filament detected, total rechecks: %i"  % (rechecks | int)) }
        FILAMENT_ISRUNOUT
    {% endif %}

[gcode_macro cfgs] 
variable_counter: 0
variable_rechecks: 0
gcode:
      { action_respond_info("var is loaded.") } 

[delayed_gcode SETFILAMENTSENSOR_ON]
gcode:
 SET_FILAMENT_SENSOR SENSOR=filament_sensor ENABLE=1

[gcode_macro PAUSE]
description: Pause the actual running print
rename_existing: PAUSE_BASE
gcode:
  SET_GCODE_VARIABLE MACRO=RESUME VARIABLE=last_extruder_temp VALUE="{printer[printer.toolhead.extruder].target}"
  PAUSE_BASE
  _TOOLHEAD_PARK_PAUSE_CANCEL {rawparams}
    
  #filament runout sensor needs to pause to
  SET_FILAMENT_SENSOR SENSOR=filament_sensor ENABLE=0

[gcode_macro RESUME]
description: Resume the actual running print
rename_existing: RESUME_BASE
variable_last_extruder_temp: 0
gcode:
  ##### get user parameters or use default #####
  {% set macro_found = True if printer['gcode_macro _CLIENT_VARIABLE'] is defined else False %}
  {% set client = printer['gcode_macro _CLIENT_VARIABLE'] %}
  {% set velocity = printer.configfile.settings.pause_resume.recover_velocity %}
  {% set sp_move        = velocity if not macro_found else client.speed_move|default(velocity) %}
  ##### end of definitions #####
  #M109 S{last_extruder_temp}
   TEMPERATURE_WAIT SENSOR=extruder minimum={last_extruder_temp-2} maximum={last_extruder_temp+2}

  _CLIENT_EXTRUDE
  RESUME_BASE VELOCITY={params.VELOCITY|default(sp_move)}

  #filament runout sensor needs to resume to
  UPDATE_DELAYED_GCODE ID=SETFILAMENTSENSOR_ON DURATION=5