Customizable front panel button for Anycubic Kossel

Description

A customizable button for the front panel LCD (a RepRapDiscount 2004) on the Anycubic Kossel line of printers (including the Anycubic Kossel Plus / Anycubic Kossel Linear Plus). Based on @HaTomX's Kill Button for Anycubic Kossel, but redone in OpenSCAD and with a few tweaks.

Since the STL previews don't show the text without using Thingiview and looking at the bottom of the print, I have provided the following options:

PANIC!
STOP!
Exclamation triangle
$#!%

*A back arrow

back chevron

I use Klipper for my Kossel Plus, so it is easy to reconfigure the purpose of the button on the LCD panel. I trust the power switch more for an emergency stop than a pin which needs to be sampled by software, and it is also on the front of the printer. Therefore I decided to repurpose this button as a quick "back" button for the LCD menus.

This can be configured in Klipper with the following in printer.cfg (this requires board_pins aliases to be setup):

[display]
#kill_pin: ^!EXP2_8
back_pin: ^!EXP2_8

This could also be repurposed in Marlin, but that requires recompilation of the firmware.

Several pre-generated STLs are provided, but the customizer (or OpenSCAD itself) can be used to generate custom text / icons. If using OpenSCAD offline, you will need to install the Font Awesome Free fonts: https://fontawesome.com/download and potentially Google Fonts if you want to use those: https://fonts.google.com/ (such as "Share Tech Mono" or "Orbitron").