cm-pixel

Open-source driver + toolkit for the Cooler Master MasterLiquid Atmos II Pixel LED hexagonal pixel screen — a clean, lightweight alternative to the official MasterCTRL app for controlling the LEDs over USB. Screen only (pump/fans are PWM and untouched).

The USB protocol was reverse-engineered from scratch; see PROTOCOL.md.

Hardware

• Cooler Master "Atmos V2 - Pixel", USB 2516:021C, plain HID (no special driver).
• 32×32 addressing grid, 556 real LEDs arranged in a hexagon, RGB888.

Install

This project uses uv. From a clone:

uv sync                 # creates .venv and installs everything (incl. uv.lock)
uv run cm-pixel list    # run the CLI

Or add it to your own uv project:

uv add cm-pixel

(Plain pip also works: pip install cm-pixel.)

Close the official MasterCTRL software first — only one program can drive the screen. On Linux you may need a udev rule for HID write access.

CLI

cm-pixel color 255 0 0           # solid red
cm-pixel image photo.png         # show an image (auto-fit to the hexagon)
cm-pixel gif spinner.gif         # play a GIF
cm-pixel text "HI"               # static centered text
cm-pixel scroll "HELLO WORLD"    # scrolling marquee
cm-pixel anim plasma             # procedural animation
cm-pixel anim fire --speed 1.5
cm-pixel list                    # list animations

Common flags: --fps, --duration, --mask (blank pixels outside the hexagon), --keep, --brightness 0-100, --rotate 0|90|180|270. Brightness and rotation are applied in software (the device has no command for them); 180° is exact, 90/270 clip slightly at the hexagon vertices.

Animations: plasma rainbow swirl ripple breathe sparkle fire starfield.

Library

from cmpixel import PixelDisplay, Canvas
from cmpixel.font import draw_text

with PixelDisplay() as d:
    c = Canvas().fill((0, 0, 20))
    c.set_pixel(16, 16, (255, 255, 255))
    draw_text(c, "GO", color=(0, 255, 0))
    d.send_canvas(c)

# play a built-in animation
from cmpixel import PixelDisplay
from cmpixel.animations import plasma
from cmpixel.media import play

with PixelDisplay() as d:
    play(d, plasma(speed=1.0), fps=30, duration=10)

How it works (short version)

A frame is 28 HID output reports of 64 bytes: 80 DD <pkt:u16> + 60 data, concatenated to 556×RGB in serpentine LED order. Streaming a frame displays it immediately — no handshake. Full details and the LED layout map are in PROTOCOL.md and cmpixel/layout.json.

Status

v0.1 — drawing, text, GIF, procedural animations, software brightness & rotation.

Disclaimer

Unofficial, not affiliated with Cooler Master. Use at your own risk; touches only the screen framebuffer (no firmware/DFU).