Wiring and Configuration

Buffer Internal Wiring Diagram

Installation Video

Buffer Connection to Mainboard and Configuration Methods

Basic Functions

• This buffer integrates filament runout detection and manual control functions:

• Filament Detection (FILAMENT_SENSOR)

  • Signal Output: After filament runout is triggered, the PB15 pin of the buffer outputs a low-level signal.

• Feed Button (FEED)

  • Single Press: The PA2 pin of the buffer outputs a 3S high-level pulse signal.
  • Long Press: The buffer will perform continuous feeding until the button is released.

• Retract Button (RETRACT)

  • Single Press: The PA3 pin of the buffer outputs a 3S low-level pulse signal.
  • Long Press: The buffer will perform continuous retraction until the button is released.

Wiring Guide

• When using the above functions, please refer to the wiring diagram below:

  

Important Note

• The MMU tool board in the diagram is only for reference of interface definition. When using it in practice, you need to:

1. Directly connect the cables to the endstop signal ports of your mainboard (e.g., Klipper, Marlin mainboard).
2. In the configuration file (e.g., printer.cfg), modify and confirm the port number configuration corresponding to PD3, PD4, and PD5 to ensure proper functionality.

Configuration Reference

[mcu LLL_PLUS]
serial:/dev/serial/by-id/usb-Klipper_stm32h723xx_12345-if00

[filament_switch_sensor Material_breakage_detection]
pause_on_runout: true
switch_pin: ^LLL_PLUS:PD3
runout_gcode:
    PAUSE
    RESPOND MSG="material shortage"
insert_gcode:
    RESPOND MSG="Detected"
event_delay: 1.0
pause_delay: 0.5

[gcode_button Load_consumables]
pin:^LLL_PLUS:PD4 # Replace with your own pin, connected to the feed pin
press_gcode:
    _Load_consumables

[gcode_button RETRACT]
pin:^!LLL_PLUS:PD5 # Replace with your own pin, connected to the retract pin
press_gcode:
    _RETRACT

[gcode_macro CONFIG]
description: Extruder configuration
variable_extruder_temp: 200    ## Temperature
variable_extruder_length: 50   ## Length
variable_extruder_speed: 5    ## Speed (mm/s)
gcode:

[gcode_macro _Load_consumables]  ## Feed
gcode:
    {% set temp = printer["gcode_macro CONFIG"].extruder_temp %}
    {% set length = printer["gcode_macro CONFIG"].extruder_length %}
    {% set speed = printer["gcode_macro CONFIG"].extruder_speed %}
    {% set feedrate = speed * 60 %}

    RESPOND MSG="Heat the extruder to {temp} °C"
    RESPOND MSG="Heating extruder to {temp} °C"
    M109 S{temp}

    RESPOND MSG="Start feeding {length}mm"
    RESPOND MSG="Starting feed of {length}mm"
    G91  ; Relative coordinate mode
    G1 E{length} F{feedrate} 
    G90  ; Absolute coordinate mode

    RESPOND MSG="Extrusion completed"
    RESPOND MSG="Extrusion completed"
    M104 S0

[gcode_macro _RETRACT]  ## Retract
gcode:
    {% set temp = printer["gcode_macro CONFIG"].extruder_temp %}
    {% set length = printer["gcode_macro CONFIG"].extruder_length %}
    {% set speed = printer["gcode_macro CONFIG"].extruder_speed %}
    {% set feedrate = speed * 60 %}

    RESPOND MSG="Heat the extruder to {temp} °C"
    RESPOND MSG="Heating extruder to {temp} °C"
    M109 S{temp}

    RESPOND MSG="Start material return {length}mm"
    RESPOND MSG="Starting retraction of {length}mm"
    G91  ; Relative coordinate mode
    G1 E-{length} F{feedrate} 
    G90  ; Absolute coordinate mode

    RESPOND MSG="Return of materials completed"
    RESPOND MSG="Material return completed"
    M104 S0

Using Trigger to Feed or Retract

• Firmware must be updated to V1.1.0

• The buffer can achieve automatic continuous feeding by detecting the following pin level states:

• Automatic Feeding: When a low-level signal is detected on pin PB5, the buffer will perform continuous feeding.

• Automatic Retraction: When a low-level signal is detected on pin PB6, the buffer will perform continuous retraction.

Wiring Guide

• When using the above functions, please refer to the wiring diagram below:

Important Note

• The MMU tool board in the diagram is only for reference of interface definition. When using it in practice, you need to:

1. Directly connect the cables to the endstop signal ports of your mainboard (e.g., Klipper, Marlin mainboard).
2. In the configuration file (e.g., printer.cfg), modify and confirm the port number configuration corresponding to PB5 and PB6 to ensure proper functionality.

Reference Configuration

• Add configuration
• Please note that this configuration should be added after the basic functions are configured

[output_pin _feeding]
pin:LLL_PLUS:PD6
shutdown_value: 0
value:0

[output_pin _material_return]
pin:LLL_PLUS:PD7
shutdown_value: 0
value:0

[gcode_macro Buffer_feeding]  ## Buffer feeding
gcode:
    {% set temp = printer["gcode_macro CONFIG"].extruder_temp %}
    {% set length = printer["gcode_macro CONFIG"].extruder_length %}
    {% set speed = printer["gcode_macro CONFIG"].extruder_speed %}
    {% set feedrate = speed * 60 %}

    RESPOND MSG="Heat the extruder to {temp} °C"
    RESPOND MSG="Heating extruder to {temp} °C"
    M109 S{temp}

    RESPOND MSG="Start feeding {length}mm"
    RESPOND MSG="Starting feed of {length}mm"
    SET_PIN PIN=_feeding VALUE=1
    G91  ; Relative coordinate mode
    G1 E{length} F{feedrate} 
    G90  ; Absolute coordinate mode


    RESPOND MSG="Extrusion completed"
    RESPOND MSG="Extrusion completed"
    SET_PIN PIN=_feeding VALUE=0
    M104 S0

[gcode_macro RBuffer_material_return]  ## Buffer retraction
gcode:
    {% set temp = printer["gcode_macro CONFIG"].extruder_temp %}
    {% set length = printer["gcode_macro CONFIG"].extruder_length %}
    {% set speed = printer["gcode_macro CONFIG"].extruder_speed %}
    {% set feedrate = speed * 60 %}

    RESPOND MSG="Heat the extruder to {temp} °C"
    RESPOND MSG="Heating extruder to {temp} °C"
    M109 S{temp}

    RESPOND MSG="Start material return {length}mm"
    RESPOND MSG="Starting retraction of {length}mm"
    SET_PIN PIN=_material_return VALUE=1
    G91  ; Relative coordinate mode
    G1 E-{length} F{feedrate} 
    G90  ; Absolute coordinate mode
    SET_PIN PIN=_material_return VALUE=0

    RESPOND MSG="Return of materials completed"
    RESPOND MSG="Material return completed"
    M104 S0

Wiring and Configuration with MDM Sensor

Function Overview

• When used with the FLY-MDM filament runout/clog sensor, the buffer can detect clogging
• Firmware must be updated to V1.1.0

Hardware Wiring

• The signal lines of the buffer should be connected to any unused general-purpose digital output pin on the mainboard, for example:

1. Connect the STEP pin from the buffer's PA5 to one of the mainboard's PWM, RGB, or 12864 pins. Note that the servo port of the BL-Touch can also be used.
2. Connect the DIR pin from the buffer's PB11 to a limit switch port on the mainboard.

• This connection is used to monitor the working status of the extruder motor, which is key to implementing clog detection.

• When using the above functions, please refer to the wiring diagram below:

Important Note

• The MMU tool board in the diagram is only for reference of interface definition. When using it in practice, you need to:

1. Directly connect the cables to the endstop signal ports of your mainboard (e.g., Klipper, Marlin mainboard).
2. In the configuration file (e.g., printer.cfg), modify and confirm the port number configuration corresponding to PD3 and PC0 to ensure proper functionality.

• MDM Reference Wiring

Reference Configuration

• Add configuration
• Please note that this configuration should be added after the basic functions are configured
• Please note that in the configuration below, you need to modify the STEP and DIR pins to match your wiring
• Also, other configurations should match your extruder configuration, otherwise clog detection may fail

  [extruder_stepper my_extra_stepper]
  extruder = extruder
  step_pin: LLL_PLUS:PE10
  dir_pin: LLL_PLUS:PD4
  rotation_distance: 17.472
  gear_ratio:50:10
  microsteps:16
  full_steps_per_rotation: 200   

Buffer Parameter Configuration

Get Serial Tool Assistant

• Use a USB cable to connect the module to your computer. Open the serial tool assistant, select the corresponding COM port, set the baud rate to 115200, then click Connect.

Note

• If your extruder configuration does not include gear_ratio, set both Driving Gear Teeth and Driven Gear Teeth to 1

Loading...

Parameter Description

Function	Configuration Command (Please enter in the serial tool)	Default	Unit	Notes
View all current parameters	Loading...	-	-	Send the command to read all current configurations.
Set motor pulse count	Loading...	916	-	Sets the number of pulses required for the motor to move one millimeter.
Set encoder detection distance	Loading...	1.73	mm	Sets the filament movement distance represented by each encoder signal.
Set running timeout duration	Loading...	60000	ms	Sets the auto-stop time in an untriggered state to prevent continuous extrusion.
Set error scaling factor	Loading...	2.0	-	Allowed error = encoder value × scale value. Example: 1.73 * 2.0 = 3.46 mm

Operation Notes:

1. Command Format: In the "Configuration Command" column above, the entire line of command (e.g., steps 916) must be entered completely.
2. Sending Method: Enter the command into the sending area of the serial assistant, then click Send.
3. Auto Save: After successfully sending the command, the parameters will take effect immediately and be automatically saved, no additional save operation is required.
4. Confirm Configuration: After modifying any parameter, send the info command to query all current parameters and verify if the configuration is correct.