Centauri Carbon Install

How to get HelixScreen onto an Elegoo Centauri Carbon: flash the community OpenCentauri COSMOS firmware first, then install HelixScreen on top of it.

Tested With

Tested and working. Prebuilt binaries ship in releases and the installer has auto-detection support. Requires the community OpenCentauri COSMOS firmware; stock Elegoo firmware is not supported (no SSH, no Klipper, no Moonraker).

Minimum COSMOS version: 26.07.0. Tested on COSMOS 26.08.0. COSMOS 0.0.7 and earlier are not supported: they lack the calibration and filament macros HelixScreen drives.

Prerequisites

Hardware:
- Elegoo Centauri Carbon (4.3” 480×272 touchscreen, Allwinner R528, armv7l)
- Network connection (WiFi or Ethernet)
- A USB stick formatted FAT32 (for the firmware flash in Step 1)
Software:
- OpenCentauri COSMOS firmware 26.07.0 or newer installed (replaces stock Elegoo firmware; ships Klipper + Moonraker + grumpyscreen/atomscreen/guppyscreen)
- SSH access: root / default password OpenCentauri (change it after install)

Installation

Step 1: Install COSMOS firmware

OpenCentauri COSMOS is a full firmware replacement for the Centauri Carbon. It ships with Klipper, Moonraker, Mainsail, and a gui-switcher that lets you pick which touch UI to run.

Download the latest update.swu from https://github.com/OpenCentauri/cosmos/releases
Copy it to the root of a FAT32-formatted USB stick
Insert the USB stick into the printer, power on
From the stock Elegoo UI, navigate to the firmware-update menu and apply the update
First boot takes 5-10 minutes while it reflashes the toolhead and bed boards; be patient
After reboot, connect to WiFi from the COSMOS UI and note the printer’s IP address

Already running COSMOS? Check the version before installing HelixScreen:

curl -s http://<ip>/printer/info | grep -o '"software_version": *"[^"]*"'
# "software_version": "Release - 26.08.0"

Mainsail shows the same string on its Machine page. Anything older than Release - 26.07.0 needs the COSMOS update above first.

If the update fails or the device won’t boot, consult the OpenCentauri install guide and emergency USB recovery docs.

Step 2: Install HelixScreen

SSH into the printer (replace <ip> with your printer’s IP):

ssh root@<ip>
# Default password: OpenCentauri

Then run the installer:

curl -sSL https://raw.githubusercontent.com/prestonbrown/helixscreen/main/scripts/install.sh | sh

Step 3: Switch back to another UI (optional)

COSMOS’s config-manager tool lets you switch between installed UIs without uninstalling HelixScreen:

config-manager ui screen_ui grumpyscreen   # or atomscreen, guppyscreen - any of the three launches HelixScreen via its wrapper
/etc/init.d/gui-switcher restart

What the Installer Does on This Printer

The installer auto-detects COSMOS, installs HelixScreen to /user-resource/helixscreen/, and registers it with gui-switcher through an allowlist wrapper (see Quirks below). It stops the currently active UI (grumpyscreen, atomscreen, or guppyscreen) and starts HelixScreen in its place.

Install directory: /user-resource/helixscreen/ (/ is read-only squashfs on COSMOS)
Init script: /etc/init.d/helixscreen; the watchdog also publishes its PID at /var/run/gui.pid so gui-switcher can stop it

Service Control and Logs

/etc/init.d/helixscreen restart

# Structured app log (written to disk; the in-memory syslog only has early startup)
tail -100 /user-resource/helixscreen/logs/helix.log

# Launcher / crash capture (startup, crash output)
tail -100 /user-resource/helixscreen/logs/launcher.log

Updating

Check the installed version on the touchscreen (Settings > Help & About > About), or from SSH with /user-resource/helixscreen/bin/helix-screen --version.

Re-run the installer with --update; it preserves your settings:

curl -sSL https://raw.githubusercontent.com/prestonbrown/helixscreen/main/scripts/install.sh | sh -s -- --update

To pin a specific version add --version vX.Y.Z, or swap --update for --clean to reinstall with fresh settings. See Updating HelixScreen for the universal details.

Uninstalling

curl -sSL https://raw.githubusercontent.com/prestonbrown/helixscreen/main/scripts/install.sh | sh -s -- --uninstall

The uninstaller reverses the gui-switcher registration, including the allowlist wrapper described below, and restores the UI that was running before.

Quirks and Notes

Slice with the COSMOS printer profile. Elegoo’s stock Centauri Carbon start G-code calls M729, and COSMOS turns M729 into an emergency stop (26.08 shows “Use COSMOS OrcaSlicer profile (or COSMOS start/end machine gcode)”; 26.07 shows “Use COSMOS start/end machine gcode”). A file sliced with the stock profile halts the printer as soon as it starts, and Klipper needs a FIRMWARE_RESTART. Re-slice with the COSMOS OrcaSlicer profile, whose start G-code is a single PRINT_START EXTRUDER=... BED=... CHAMBER=... line
Moonraker listens on port 80 on COSMOS directly (no nginx). Enter 80 as the port at the wizard’s connection step; the 7125 default does not apply on this printer
Factory white-balance calibration: the cc1 preset ships with per-channel panel gain so colors look neutral out of the box on the Centauri Carbon’s 4.3” panel. No manual tuning needed
The config-manager allowlist: COSMOS’s config-manager has a fixed allowlist for the screen_ui slot. The installer handles this automatically via an init-script wrapper so HelixScreen can be selected without patching COSMOS itself; the uninstaller fully reverses it

Testing on this printer? Please report your results via GitHub Issues or Discord.