Wiring and Configuration

Buffer Internal Wiring Diagram

Installation Video

How to Connect the Buffer to the Mainboard and Configuration Methods

Important Note

• The MMU Toolboard shown in the wiring example below is only for reference regarding the interface definition. When actually using it, you need to:

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

Basic Functions

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

• Filament Runout 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 high-level pulse signal for 3 seconds.
  • Long Press: The buffer will perform a continuous feeding action until the button is released.

• Retract Button (RETRACT)

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

Wiring Guide

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

  

Important Note

• The MMU Toolboard shown in the diagram is only for reference regarding the interface definition. When actually using it, you need to:

1. Directly connect the cables to the endstop signal ports of your KLIPPER mainboard.
2. In the configuration file (e.g., printer.cfg), modify and confirm the corresponding port numbers for PD3, PD4, and PD5, to ensure the functionality works properly.

Configuration Reference

Reference Configuration Using the Mainboard

[filament_switch_sensor Material_breakage_detection]
pause_on_runout: true
switch_pin: ^PD3 # Replace with the pin you are using
runout_gcode:
    PAUSE
    RESPOND MSG="Filament runout triggered"
    #SET_IDLE_TIMEOUT TIMEOUT=86400
insert_gcode:
    RESPOND MSG="Triggered feeding"
event_delay: 2.0
pause_delay: 2.0
debounce_delay:2.0

[gcode_button Trigger Feeding]
pin:^!PD4 # Replace with the pin you are using, connected to the feed pin
press_gcode:
    RESPOND MSG="Triggered feeding"
    # Custom Gcode

[gcode_button Trigger Retraction]
pin:^!PD5 # Replace with the pin you are using, connected to the retraction pin
press_gcode:
    RESPOND MSG="Triggered retraction"
    # Custom Gcode

Using Trigger for Buffer Feeding or Retraction Function

• The firmware needs to be updated to V1.1.0

• The buffer can perform automatic continuous feeding by detecting the following pin level status:

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

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

Wiring Guide

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

Important Note

• The MMU Toolboard shown in the diagram is only for reference regarding the interface definition. When actually using it, you need to:

1. Directly connect the cables to the endstop signal ports of your KLIPPER mainboard.
2. In the configuration file (e.g., printer.cfg), modify and confirm the corresponding port numbers for PB5 and PB6, to ensure the functionality works properly.

Reference Configuration

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

Reference Configuration Using the Mainboard

[output_pin _Feed Button]
pin:!PD6 # Replace with the pin you are using
debounce_delay:2.0
value:0

[output_pin _Retract Button]
pin:!PD7 # Replace with the pin you are using
debounce_delay:2.0
value:0

[gcode_macro Buffer Feeding]  ## Buffer Feeding
gcode:
    SET_PIN PIN=_Retract_Button VALUE=0
    SET_PIN PIN=_Feed_Button VALUE=1
    G4 P10000 # 10 seconds
    SET_PIN PIN=_Feed_Button VALUE=0

[gcode_macro Buffer Retraction]  ## Buffer Feeding
gcode:
    SET_PIN PIN=_Feed_Button VALUE=0
    SET_PIN PIN=_Retract_Button VALUE=1
    G4 P10000 # 10 seconds
    SET_PIN PIN=_Retract_Button VALUE=0

Wiring and Configuration Using the MDM Sensor

Function Overview

• When used with the FLY-MDM filament runout/clog sensor, the buffer can achieve clog detection functionality.
• The firmware needs to be updated to V1.1.0.

Hardware Wiring

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

1. Connect the STEP from the buffer's PA5 to any of the mainboard's PWM, RGB, or 12864 pins. Please note that the servo port of the BL-Touch can also be used.
2. Connect the DIR from the buffer's PB11 to an endstop port on the mainboard.

• This connection is used to monitor the working status of the extruder motor and is key to achieving clog detection.

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

Important Note

• The MMU Toolboard shown in the diagram is only for reference regarding the interface definition. When actually using it, you need to:

1. Directly connect the cables to the endstop signal ports of your KLIPPER mainboard.
2. In the configuration file (e.g., printer.cfg), modify and confirm the corresponding port numbers for PD3 and PC0, to ensure the functionality works properly.

• MDM Reference Wiring

Reference Configuration

• Add the configuration
• Please note that this configuration must be added after the basic functions are configured.
• Please note that in the configuration below, you must modify the STEP and DIR pins to match the ones you have wired.
• Also, other configurations must match your extruder settings, otherwise clog detection will fail.

Reference Configuration Using the Mainboard

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

Buffer Parameter Configuration

Get via Serial Tool Assistant

• Connect the module to the computer using a USB cable, open the serial tool assistant, select the corresponding COM port, set the baud rate to 115200, and click Connect.

Note

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

Loading...

Parameter Description

Function Description	Configuration Command (Please enter in the serial tool)	Default Value	Unit	Notes
View all current parameters	Loading...	-	-	Send command to read all current configurations.
Set motor pulse count	Loading...	916	-	Set the number of pulses required for the motor to move per millimeter.
Set encoder detection distance	Loading...	1.73	mm	Set the filament movement distance represented by each encoder signal.
Set run timeout duration	Loading...	60000	ms	Set the auto-stop time in an untriggered state to prevent continuous extrusion.
Set error scaling factor	Loading...	2.0	-	Allowed error = encoder value X scale value. Example: 1.73 * 2.0 = 3.46 mm
Set speed control command	Loading...	260	mm	Set the buffer operating speed, maximum 600 (revolutions/minute), firmware needs to be updated to V1.1.1

Operation Notes:

1. Command Format: In the "Configuration Command" column of the above table, a full line of command (e.g., steps 916) is the content that needs to be fully entered.
2. Sending Method: Enter the command in the sending area of the serial assistant, then click Send.
3. Auto Save: Once the command is sent successfully, the parameter 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 to verify whether the configuration is correct.