Power-off Shutdown and Power-off Resuming

Note

• Fly_FAST system is required; other systems are not supported!
• Power-off shutdown and power-off resuming functions conflict with each other and cannot be enabled simultaneously.
• If only the power-off shutdown function is enabled, the power-off resuming function will be unavailable.
• Klipper connection must be properly configured and maintained for the power-off resuming function to take effect. After this function is triggered, the system will automatically enter the shutdown process.

Wiring

Important Notes

• Notes on FLY C8 power-off shutdown/resuming functions:
• When connecting other mainboards via USB, the 5V power line must be disconnected or isolated (e.g., by cutting the cable or using a USB cable with only data pins).
• The KPPM module must be connected to three points; otherwise, it will not function properly.
• If the 5V connection between the slave and master devices cannot be disconnected, the mainboard must be completely powered off before restarting; otherwise, it may fail to boot properly.

FLY-C8 Using 5V Wiring

• FLY-Pi-V2 using 5V wiring
  

FLY-C8 Using USB Wiring

• FLY-Pi-V2 using USB wiring
  

Configuration

Power-off Shutdown

Configure Power Failure Shutdown

Note

• Method to configure power failure shutdown

• Enter the device's IP address in the browser 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 -> Filter hidden files and folders as shown in the left image below.
  • In Mainsail, check the option -> Show hidden files as shown in the right image below.
  • You should now see the .flyos-config folder. Enter this folder and locate the sys-config.conf file.
  • The sys-config.conf file is a symbolic link to the config.txt configuration file in the removable disk named FlyOS-Conf.
  
  • Open the sys-config.conf file and locate the two configurations shutdown_pin_state and shutdown_pin=, and modify them to match the configurations below:
  • Please note that shutdown_pin=none needs to be deleted or preceded by a # symbol.

shutdown_pin_state=0
shutdown_pin=PA21

• Then Save -> Close, and restart the system.

Power-off Resuming

Disable Power Failure Shutdown

Note

• The power failure shutdown function needs to be disabled, otherwise the power failure resume printing function cannot be used.
• The power failure resume printing function includes an automatic shutdown feature after saving progress.
• Please ensure that no other power supply is connected to the host computer, otherwise it will not be able to power on.

• 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 -> "Filter hidden files and folders" as shown on the left in the image below.
  • In Mainsail, check -> "Show hidden files" as shown on the right in the image below.
  • You will now see the .flyos-config folder. Inside this folder is the sys-config.conf file.
  • The sys-config.conf file is a symbolic link to the config.txt configuration file in the removable disk FlyOS-Conf.
  
  • Open the sys-config.conf file and locate the configurations shutdown_pin_state and shutdown_pin=.
  • Add a # at the beginning of these configuration lines.
  • Then click Save -> Close and restart the device.
  

plr.cfg Configuration File

• In the printer configuration page, locate the plr.cfg file.
• Clear 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: host:gpiochip1/gpio21
is_shutdown: True # Whether to perform shutdown operation, enabled by default
paused_recover_z: -2.0 # If the print was paused when powered off, the Z-axis movement distance for resuming print, default is no movement
start_gcode:
    # GCode executed before resuming print
    # All parameters saved before power loss can be accessed via {PLR}
    # You can 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 reach set temperature
    G91                             ; Relative coordinates
    G1 Z2 F100                      ; Raise Z, prepare for X and Y homing
    G90                             ; Absolute coordinates
    G28 X Y                         ; Home XY
    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 reach set temperature
    M109 S{PLR.extruder.target}     ; Wait for extruder to reach set temperature
    M83                             ; Relative extrusion
    # G1 E0.5 F400                  ; Extrude a little
layer_count: 2 # Execute layer_change_gcode after resuming for {layer_count} layers
layer_change_gcode:                
    # GCode executed after resuming for {layer_count} layers
    M118 Resume print speed
    M106 S{PLR.fan_speed}             ; Enable part 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 executed before shutdown
    M118 Low power voltage, shutting down
    # M112 ; Emergency stop

• After saving the configuration file above,

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

  
  [include plr.cfg]
  

• Click Save and Restart in the upper right corner.

• At this point, the power loss resume feature of Klipper has been configured.

About [homing_override] Description

Note

• If using [homing_override], do not arbitrarily set the homing position in [homing_override]. We are not responsible for failed power loss resume caused by this.
• Below is the configuration description for [homing_override].

• Description
  • [force_move]: Enable the force move feature, allowing forced movement to a specified position.
  • [force_move] replaces the set_position_z functionality in [homing_override]. Failure to configure as instructed may cause power loss resume to fail.
  • The [homing_override] configuration below is to correctly home the Z-axis during power loss resume.

[force_move]
enable_force_move: true


[homing_override]
axes: z
gcode:
    {% set max_x = printer.configfile.config["stepper_x"]["position_max"]|float %}
    {% set max_y = printer.configfile.config["stepper_y"]["position_max"]|float %}
    {% if 'z' not in printer.toolhead.homed_axes %}
        SET_KINEMATIC_POSITION Z=0
        G90
        G0 Z5 F600
    {% endif %}
    {% set home_all = 'X' not in params and 'Y' not in params and 'Z' not in params %}

    {% if home_all or 'X' in params %}
    G28 X
    {% endif %}

    {% if home_all or 'Y' in params %}
    G28 Y
    {% endif %}

    {% if home_all or 'Z' in params %}
    G0 X{max_x / 2} Y{max_y / 2}  F3600 
    G28 Z
    G1 Z10 F2000
    {% endif %}

• About the Z-axis lift description
  • This configuration is executed only when the Z-axis is not homed, and does not affect normal usage.

  {% if 'z' not in printer.toolhead.homed_axes %}
      SET_KINEMATIC_POSITION Z=0
      G90
      G0 Z5 F600
  {% endif %}

Testing

• Print any file, and during printing click the Emergency Stop button to simulate power loss.
• Then click Firmware Restart and wait for Klipper to reconnect normally.
• If a pop-up appears in the web interface or KlipperScreen, it indicates the power loss resume function is working properly.
• You can further test with actual power outage scenarios.