Klipper Homing Timeout Issue

Problem Description

A communication timeout error occurs during the homing process:

Error during homing z: Communication timeout during homing

This primarily occurs during Z-axis homing with multiple MCUs, where Klipper requires a response within 0.025 seconds.

Adjust Timeout Duration

Method 1: Adjust Timeout Duration

Modify Timeout Configuration

sed -i 's/TRSYNC_TIMEOUT = [0-9.]*$/TRSYNC_TIMEOUT = 0.05/' ~/klipper/klippy/mcu.py

Restart Service to Apply Changes

sudo systemctl restart klipper

Related Commands

# View current settings
grep "TRSYNC_TIMEOUT =" ~/klipper/klippy/mcu.py

# Restore default settings
sed -i 's/TRSYNC_TIMEOUT = [0-9.]*$/TRSYNC_TIMEOUT = 0.025/' ~/klipper/klippy/mcu.py

Manage KlipperScreen

Method 2: Manage KlipperScreen

Temporarily disable KlipperScreen to free up system resources and resolve communication timeout issues during the homing process.

1. Download Required Files

Standard System:

git clone https://cnb.cool/3dmellow/public/klipper-klipperscreen-manager
curl -# -L --retry 3 --retry-delay 2 -o ~/klipper/klippy/extras/gcode_shell_command.py https://raw.githubusercontent.com/dw-0/kiauh/master/kiauh/extensions/gcode_shell_cmd/assets/gcode_shell_command.py

Fast System:

cd /data
git clone https://cnb.cool/3dmellow/public/klipper-klipperscreen-manager
curl -# -L --retry 3 --retry-delay 2 -o /data/klipper/klippy/extras/gcode_shell_command.py https://raw.githubusercontent.com/dw-0/kiauh/master/kiauh/extensions/gcode_shell_cmd/assets/gcode_shell_command.py

2. Set Script Permissions

Standard System:

cd ~/klipper-klipperscreen-manager
chmod +x ~/klipper-klipperscreen-manager/scripts/*.sh

Fast System:

cd /data/klipper-klipperscreen-manager
chmod +x /data/klipper-klipperscreen-manager/scripts/*.sh

3. Create Configuration File

• Create a file named klipper_macros.cfg in the Klipper configuration directory.
• Add the following line at the top of the printer.cfg file:

  [include klipper_macros.cfg]

4. Configure Macro Commands

• Add the following content to the klipper_macros.cfg file:
• Please note that /data/klipper-klipperscreen-manager/scripts/ should be replaced with the actual path:

# ===== KlipperScreen Control Macros =====
# Author: MELLOW-Zhang Wei
# Description: Used to manage the shutdown and automatic recovery of KlipperScreen

[gcode_shell_command disable_klipperscreen]
command: sh /data/klipper-klipperscreen-manager/scripts/disable_klipperscreen.sh
timeout: 5.0
verbose: True

[gcode_shell_command enable_klipperscreen]
command: sh /data/klipper-klipperscreen-manager/scripts/enable_klipperscreen.sh
timeout: 5.0
verbose: True

[gcode_macro RESTART_KLIpperSCREEN]
variable_time: 60  # Default wait time (seconds)
gcode:
    {% set wait_time = params.TIME|default(printer["gcode_macro RESTART_KLIpperSCREEN"].time)|int %}
    {action_respond_info("Wait time: %s seconds" % wait_time)}
    RUN_SHELL_COMMAND CMD=disable_klipperscreen PARAMS={wait_time}

[gcode_macro ENABLE_KLIpperSCREEN]
gcode:
    {action_respond_info("Immediately start KlipperScreen")}
    RUN_SHELL_COMMAND CMD=enable_klipperscreen

5. Usage

Temporarily Disable KlipperScreen:

# Use the default wait time of 60 seconds
RESTART_KLIpperSCREEN

# Use a custom wait time (120 seconds)
RESTART_KLIpperSCREEN TIME=120

Manually Restart KlipperScreen Immediately:

ENABLE_KLIpperSCREEN

Working Principle

This method temporarily disables the KlipperScreen interface to free up system resources and reduce CPU load, thereby avoiding communication timeout issues during the homing process.

Prerequisites

• Ensure Klipper is installed
• The current user is the Klipper installation user
• File paths are correct