Power Off Shutdown and Power Loss Resume

Important Notice

Power Off Shutdown and Power Loss Resume features are mutually exclusive and cannot be enabled simultaneously
If only the power-off shutdown function is enabled, the power loss resume function will be unavailable
Klipper must be properly configured and connected for the power loss resume function to work. Once triggered, this function will automatically initiate the shutdown process

Feature Configuration

Power Off Shutdown
Power Loss Resume

Configure Power Off Shutdown

Notice

Please follow the steps below to configure the power off shutdown feature

Access the device configuration page
- Enter the device IP address in the browser address bar, for example: http://192.168.1.2/
Display hidden files
- Fluidd: Uncheck "Filter hidden files and folders"
- Mainsail: Check "Show hidden files"
Edit configuration file
- Locate and enter the .flyos-config folder
- Open the sys-config.conf file (this file is a symbolic link to config.txt in the FlyOS-Conf disk)
Modify configuration parameters
- Locate the shutdown_pin_state and shutdown_pin configuration entries
- Update them to the following:
```
shutdown_pin_state=1
shutdown_pin=xxxxx
```
- Ensure that shutdown_pin=none is either deleted or commented out (add # in front)
- Here, xxxxx is the actual GPIO number used; choose the correct GPIO according to your device model:
Save and restart
- Save the modified configuration file
- Close the file and restart the system

Disable Power Off Shutdown Function

Notice

The power-off shutdown function must be disabled, otherwise the power loss resume function will not work
The power loss resume function includes the ability to automatically shut down after saving progress
Please ensure no other power is connected to the host, otherwise normal shutdown will not occur

Access the device configuration page
- Enter the device IP address in the browser address bar, for example: http://192.168.1.2/
Display hidden files
- Fluidd: Uncheck "Filter hidden files and folders"
- Mainsail: Check "Show hidden files"
Edit configuration file
- Locate and enter the .flyos-config folder
- Open the sys-config.conf file

Comment out power-off shutdown configuration
- Locate the shutdown_pin_state and shutdown_pin configuration entries
- Add # in front of these two configurations to comment them out
Save and restart
- Save the modified configuration file
- Close the file and restart the system

Configure Power Loss Resume Function

Edit the plr.cfg configuration file

On the printer configuration page, find or create the plr.cfg file
Clear the file content and paste the following configuration:
Please modify the power_pin parameter according to the actual GPIO number used

[mcu host]   
serial: /tmp/klipper_host_mcu

[power_loss_resume]
power_pin: xxxx
is_shutdown: True # Whether to execute shutdown operation, default is enabled
paused_recover_z: -2.0 # If the print is paused when powered off, this is the Z-axis movement distance for resuming, default is no movement
start_gcode:
   # G-code to execute before resuming printing
   # All parameters saved before power loss can be retrieved via {PLR}
   # You can use M118 {PLR} to output all available parameters
   # M118 {PLR}
   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}]
   {% if PLR.bed.target > 0 %}
      M140 S{PLR.bed.target}      ; Set bed temperature
   {% endif %}
   {% if PLR.extruder.target > 50 %}
      M104 S{PLR.extruder.target - 10}  ; Wait for extruder to heat to set temperature
   {% endif %}
   G91                             ; Relative coordinates
   G1 Z2 F100                      ; Lift Z, prepare for X,Y homing
   G90                             ; Absolute coordinates
   G28 X Y                         ; Home XY
   {% if PLR.bed.target > 0 %}
      M190 S{PLR.bed.target}      ; Wait for bed to heat to set temperature
   {% endif %}
   {% if PLR.extruder.target > 0 %}
      M109 S{PLR.extruder.target}  ; Wait for extruder to heat to set temperature
   {% endif %}
   M83                              ; Relative extrusion
   # G1 E0.5 F400                   ; Extrude a bit
layer_count: 2 # Execute layer_change_gcode after resuming for {layer_count} layers
layer_change_gcode:
   # G-code to execute after resuming for {layer_count} layers
   M118 Resume print speed
   M106 S{PLR.fan_speed}             ; Turn on part cooling fan
   M220 S{PLR.move_speed_percent}    ; Set requested move speed percentage
   M221 S{PLR.extrude_speed_percent} ; Set requested extrusion speed percentage
shutdown_gcode:
   # G-code to execute before shutdown
   M118 Low power voltage, shutting down
   # M112 ; Emergency stop

Include configuration file
- Open the printer.cfg file and add the following at the beginning:
```
[include plr.cfg]
```
- Click save and restart

Configure Homing Override

Important Notes

If using [homing_override], do not arbitrarily set homing positions in the configuration
Incorrect configuration may cause the power loss resume function to fail

Configuration Description

[force_move]: Enables the force move feature, allowing forced movement to specified positions
[force_move] replaces the set_position_z functionality in [homing_override]
The following configuration ensures that the Z-axis can home correctly 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 %}

Z-axis lift description This configuration only executes when the Z-axis has not been homed and does not affect normal operation:

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

Function Test

Step 1: Simulate Power Loss Test

Start printing any file
During the print, click the Emergency Stop button to simulate a power loss situation
Click Firmware Restart and wait for Klipper to reconnect
Check if a pop-up appears on the web interface (a pop-up indicates the function is working correctly)
A real power loss test can be performed later to verify the reliability of the function

Step 2: Real Power Loss Test

Test preparation: Confirm the status of the indicator light next to the host (the LED should be blinking during normal operation)
Power loss test: Directly disconnect the power while the device is operating normally
Check indicator light: Observe whether the indicator light completely turns off within 5 seconds
- Turns off: The power-off shutdown function is working correctly
- Does not turn off: The automatic shutdown function is not effective, check the configuration
Recovery test: Wait at least 5 seconds before reconnecting the power
Function verification:
- Pop-up appears: The power loss resume function is working correctly
- No prompt: The power loss resume function is not activated, check the configuration

Feature Configuration​

Configure Power Off Shutdown​

Disable Power Off Shutdown Function​

Configure Power Loss Resume Function​

Configure Homing Override​

Function Test​

Step 1: Simulate Power Loss Test​

Step 2: Real Power Loss Test​