check_image.cfg

# Include the timelapse.cfg file
[include timelapse.cfg]

[extended_template]
# This section defines the path to the configuration file for a 3D print error detector using a camera
path: ~/klipper-camera-watchdog/config.yaml

# Move Back Macro - This macro helps the printer head return to its previous position
[extended_macro MOVE_BACK]
# This macro stores the current position of the head and then uses Gcode commands to move back to that position. 

# These variables will store the X, Y, and Z coordinates of the printer head when the macro is called
variable_saved_x: 0.0
variable_saved_y: 0.0
variable_saved_z: 0.0

gcode:
  # Set absolute positioning mode (G90) - This tells the printer to use absolute coordinates instead of relative ones
  G90

  G1 Z{saved_z} F300  # Move to saved Z position at 5 mm/s
  G1 X{saved_x} Y{saved_y} F6000  # Move to saved X and Y position at 100 mm/s

# Check Print Macro - This macro checks for movement during printing
[extended_macro CHECK_PRINT]

gcode:
  {% set cancel_print = check_image() %}  # This line calls a function to check the camera image for movement

  {% if cancel_print == "Movement detected" %}
    G90
    CANCEL_PRINT  # This command likely triggers a print cancellation
  {% endif %}

# Check Image Macro - This macro sets up the printer to capture the image, runs the macro to take the picture and the macro to check if movement is detected
#                     and then sets up the printer to continue printing
[extended_macro CHECK_IMAGE]

gcode:
  {% set position = printer.gcode_move.gcode_position %}  # This line gets the current printer head position

  # Save the current position for the MOVE_BACK macro to use later
  SET_GCODE_VARIABLE MACRO=MOVE_BACK VARIABLE=saved_x VALUE="{position.x}"
  SET_GCODE_VARIABLE MACRO=MOVE_BACK VARIABLE=saved_y VALUE="{position.y}"
  SET_GCODE_VARIABLE MACRO=MOVE_BACK VARIABLE=saved_z VALUE="{position.z}"

  # Save the current printer state 
  SAVE_GCODE_STATE NAME=saved_state1

  # Prime the extruder a bit (-10mm)
  M83  # Set relative extrusion for the extruder
  G1 E-10 F300  # Retract 10mm

  # Move to a specific position (X0 Y220 Z20) for camera capture
  G90
  G1 X0 Y220 F6000  # Move to X0 Y220 at 100 mm/s
  G1 Z20 F300  # Move to Z20 at 5 mm/s

  # Restore the printer state to what it was before moving for camera capture
  RESTORE_GCODE_STATE NAME=saved_state1

  # Capture a timelapse frame
  TIMELAPSE_TAKE_FRAME

  # Move the head back to the previously saved position using the MOVE_BACK macro
  MOVE_BACK

  # Call the CHECK_PRINT macro to cancel the print if movement is detected
  CHECK_PRINT

  # Save the current printer state 
  SAVE_GCODE_STATE NAME=saved_state2

  # Retract the filament a bit (10mm)
  M83  # Set relative extrusion for the extruder
  G1 E10 F300  # Extrude 10mm to prime the extruder

  # Restore the printer state to what it was before priming the extruder
  G90
  RESTORE_GCODE_STATE NAME=saved_state2