Klipper Power Loss Resume Function

Overview

• The Klipper power loss resume function refers to the ability of Klipper to automatically recover its printing state after being powered on again following a power outage.
• The power loss resume function can only be used when combined with the FAST system.
• PI-V2 requires the use of the KPPM power loss module to enable this feature.
• Not applicable for machines where the Z-axis will move after a power outage.
• Introduction to KPPM

Configuration

Disable Power-off Shutdown

Note

• Power-off shutdown must be disabled, otherwise power-off resume printing cannot be used.
• The power-off resume printing has an automatic shutdown function after saving the progress.

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

• Access the configuration page

  • Open the device IP address in the browser, for example: http://192.168.1.2/
  • In Fluidd, uncheck the option shown on the left figure -> "Filter hidden files and folders".
  • In Mainsail, check the option shown on the right figure -> "Show hidden files".
  • At this point, you can see the .flyos-config folder. Enter this folder to find the sys-config.conf file.
  • The sys-config.conf file is a symbolic link to the config.txt file in the removable disk FlyOS-Conf.
  
  • Open the sys-config.conf file and locate the configurations shutdown_pin_state and shutdown_pin=
  • Add # before these configurations
  • Then save, close, and restart the system
  

plr.cfg Configuration File

Note

• Please replace the following content in the configuration file: (PINS)
• with gpiochip1/gpio21

• In the printer configuration page, find the plr.cfg file.
• Empty the contents inside and paste the configuration below into it.
• The content of the configuration file is as follows:

[mcu host]   
serial: /tmp/klipper_host_mcu

[power_loss_resume]
power_pin: (PINS)
is_shutdown: True # Whether to execute shutdown operation, enabled by default
paused_recover_z: -2.0 # Z movement distance when resuming print from pause during shutdown, default is no movement
start_gcode:
    # G-code executed before resuming print
    # All parameters saved before power-off can be accessed via {PLR}
    # Use M118 {PLR} to output all available parameters
    M118 Start 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 up to set temperature
    G91                             ; Relative coordinates
    G1 Z2 F100                      ; Lift Z, prepare for X,Y reset
    G90                             ; Absolute coordinates
    G28 X Y                         ; Reset 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 up to set temperature
    M109 S{PLR.extruder.target}     ; Wait for extruder to heat up to set temperature
    M83                             ; Relative extrusion
    # G1 E0.5 F400                  ; Extrude a bit
layer_count: 2 # Resume print after specified number of layers, execute layer_change_gcode
layer_change_gcode:                
    # G-code to execute after resuming {layer_count} layers
    M118 Resume print speed
    M106 S{PLR.fan_speed}             ; Turn on material 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:
    # G-code to execute before shutdown
    M118 Low voltage, shutting down
    # M112 ; Emergency stop

Note

• The start_gcode macro in the above configuration file may need to be modified according to the actual machine conditions.
• Note that if [homing_override] is used, do not arbitrarily set the homing position in [homing_override]. Any failure caused by this is not responsible.
• Note that if [gcode_macro _CLIENT_VARIABLE] is used, find variable_custom_park_dz and set it to 0 `

• After saving the above configuration file,

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

  
  [include plr.cfg]
  

• Click the "Save and Restart" button in the top right corner.

• At this point, the Klipper power-off resume printing function has been configured.

Testing

• Print any file, and click the "Emergency Stop" button during printing to simulate a power outage.
• Click "Firmware Restart" again, wait for Klipper to connect normally.
• If a pop-up prompt appears on the webpage or KlipperScreen, it indicates that the power-off resume printing function is working properly.
• You can continue to test real power-outage situations later.