KlipperScreen on a PostmarketOS phone - Configuration Manual

for some time I had a crealty ender 3 that had klipper installed. I wanted to use klipper screen insted of the trush blue lcd. I have a poco x3 phone that running PostmarketOS (https://postmarketos.org) so thoght way not to try using it as a screen. my goal was making the experiance as smooth as possible, so I`have tried to reduce the steps from power on to usable state.

The setup

printer

1. a 3D printer running klipper with kiauh.
2. setting Up klipperscreen with kiauh.
3. installing vnc server on the printer
4. create /home/user/KlipperScreen/scripts/launch_KlipperScreen.sh
5. set up network settings

phone

1. install pmOS stable with Xorg window manager - xfce, open box, etc..
2. set up network settings
3. set auto loggin tty
4. set up startx

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1. Setting Up Remmina with VNC

Description

This section covers how to configure Remmina to automatically connect to a VNC server and retry if disconnected.

Configuration

Create or modify ~/.xinitrc:

#!/bin/sh
exec startxfce4 & exec remmina -c vnc://user@172.16.42.2 --disable-news --disable-stats --disable-toolbar --enable-fullscreen

This ensures that Remmina starts with XFCE and automatically connects to the VNC server.

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2. Rotating and Resizing the Display

Description

To ensure the display is correctly rotated and sized for VNC usage.

Configuration

Run the following command to set the correct resolution and rotation:

xrandr --output VNC-0 --mode 1080x2400 --rotate right

To make this change permanent, add it to a startup script or the VNC startup configuration.

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3. Preventing Screen from Turning Off

Description

This prevents the screen from going into power-saving mode.

Configuration

Add the following command to the startup script:

xset s off -dpms

This disables screen blanking and power management.

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4. Auto Shutdown on Network Disconnection

Description

Automatically powers off the system if usb0 network interface loses connectivity.

Script

Create a script at /usr/local/bin/usb0-shutdown.sh:

#!/bin/sh
while true; do
    if ! ping -c 1 172.16.42.2 >/dev/null 2>&1; then
        echo "Network lost, shutting down..."
        poweroff
    fi
    sleep 5
done

Make the script executable:

chmod +x /usr/local/bin/usb0-shutdown.sh

Create an OpenRC service at /etc/init.d/usb0-shutdown:

#!/sbin/openrc-run
depend() {
    need net
}

start() {
    /usr/local/bin/usb0-shutdown.sh &
}

stop() {
    pkill -f usb0-shutdown.sh
}

Enable and start the service:

chmod +x /etc/init.d/usb0-shutdown
rc-update add usb0-shutdown default
rc-service usb0-shutdown start

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5. Configurations on the Printer

Description

This section details the VNC setup and display configuration on the printer.

Configuration

Modify the VNC startup script:

#!/bin/bash
# Use display 10 to avoid clashing with local X server, if any
Xtigervnc -rfbport 5900 -noreset -AlwaysShared -SecurityTypes none :10&
DISPLAY=:10 $KS_XCLIENT&
wait

Ensure the correct resolution and rotation are applied:

xrandr --output VNC-0 --mode 1080x2400 --rotate right

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This manual serves as a reference for configuring the system with these customizations. Let me know if anything needs to be added or changed!