Power Loss Resume Function in Klipper

Overview

• The Power Loss Resume function in Klipper refers to the ability to automatically restore the printing status of Klipper after it loses power and is re-powered.

• This function can only be used with the FAST system.

• Lite2.1 requires the KPPM power loss module to be used.

• Not suitable for models where the Z-axis may shift after a power outage.

• Introduction to KPPM

  Configuration

  Turn off power-off shutdown

  Note

  • Power-off shutdown needs to be turned off, otherwise the power failure resume function cannot be used.
  • The power failure resume has a function to automatically shut down after saving the progress.
  • Please ensure that there is no other power connected to the host, otherwise it will not be able to start up

  • Enter the device's IP address in the browser's address bar, for example: http://192.168.6.179

  • Enter the configuration page

    • Open the device ip address in the browser, for example: http://192.168.1.2/
    • In fluidd, as shown on the left in the picture, uncheck -> filter hidden files and folders.
    • In mainsail, as shown on the right in the picture, check -> show hidden files.
    • At this point, you can see the .flyos-config folder, entering this folder will have the sys-config.conf file.
    • The sys-config.conf file is a soft link of the configuration file config.txt in the removable disk FlyOS-Conf.
    
    • Open the sys-config.conf file, find the configurations shutdown_pin_state and shutdown_pin=
    • Add a # before these configurations
    • Then save -> close and restart
    

  plr.cfg configuration file

  Note

  • Replace the following in the configuration file: (PINS)
  • with host:gpiochip1/gpio8
  • In the printer configuration page, find the plr.cfg file.
  • Empty its content and paste the configuration below
  • The configuration file content is as follows:

  [mcu host]   
  serial: /tmp/klipper_host_mcu
  
  [power_loss_resume]
  power_pin: (PINS)
  is_shutdown: True # Whether to perform shutdown operation, enabled by default
  paused_recover_z: -2.0 # Z movement distance when resuming printing if paused at power loss, default is no movement
  start_gcode:
      # Gcode to execute before resuming printing
      # All parameters saved before power loss can be obtained through {PLR}
      # Use M118 {PLR} to output all available parameters
      M118 Resuming print: {PLR.print_stats.filename}
      M118 Interruption position: X:[{PLR.POS_X}] Y:[{PLR.POS_Y}] Z:[{PLR.POS_Z}] E:[{PLR.POS_E}]
      M140 S{PLR.bed.target}      ; Set bed temperature
      M104 S{PLR.extruder.target-10}  ; Set extruder temperature
      M109 S{PLR.extruder.target-10}  ; Wait for extruder to heat to set temperature
      G91                             ; Relative coordinates
      G1 Z2 F100                      ; Lift Z, prepare to home X,Y
      G90                             ; Absolute coordinates
      G28 X Y                         ; Home X Y
      M140 S{PLR.bed.target}          ; Set bed temperature
      M104 S{PLR.extruder.target}     ; Set extruder temperature
      M190 S{PLR.bed.target}          ; Wait for bed to heat to set temperature
      M109 S{PLR.extruder.target}     ; Wait for extruder to heat to set temperature
      M83                             ; Relative extrusion
      # G1 E0.5 F400                  ; Extrude a little
  layer_count: 2 # Execute layer_change_gcode after resuming for specified layers
  layer_change_gcode:                
      # Gcode to execute after resuming {layer_count} layers
      M118 Resume print speed
      M106 S{PLR.fan_speed}             ; Turn on cooling fan
      M220 S{PLR.move_speed_percent}    ; Set requested speed percentage
      M221 S{PLR.extrude_speed_percent} ; Set requested extrusion speed percentage
  shutdown_gcode:
      # Gcode to execute before shutdown
      M118 Low power voltage, shutting down
      # M112 ; Emergency stop
  

  Note

  • The start_gcode macro in the above configuration file may need to be modified, specific modifications should be based on the actual machine.
  • Note that if [homing_override] is used, do not随意 set the homing position in [homing_override]. If the power failure resume fails, we are not responsible.
  • Note that if [gcode_macro _CLIENT_VARIABLE] is used, find variable_custom_park_dz and set it to 0

  • After saving the configuration file above

  • Open the printer.cfg file, and add the following content at the beginning of the file:

    
    [include plr.cfg]
    

  • Click save and restart in the top right corner.

  • At this point, the Klipper power failure resume function has been configured.

  Test

  • Print any file, click the Emergency Stop button during printing to simulate a power failure.
  • Click Firmware Restart again, wait for Klipper to connect normally.
  • If a pop-up appears on the web page or KlipperScreen, it means the power failure resume function is working properly.
  • Subsequent tests can be done with real power outages.