LED Text & Logo Display
Overview
Set up your panel first
Accessing via raspi-config
Available Options
Command Line Usage
Display Custom Text
Display Logos
Custom Logos
Configuration
Troubleshooting
Text or logo upside down or scrambled
LED settings come back after a restart
Colours appear wrong
LEDs not turning on
Turn off LEDs
For developers
Python API
Demo scripts

LED Text & Logo Display

Display custom text, logos, and visual effects on the RasQberry LED panel.

Overview

The LED Display feature allows you to:

Display custom text with various colours and effects
Show pre-built logos (IBM, RasQberry, custom)
Run animated text and color effect demos
Create your own logo images

Set up your panel first

RasQberry needs to know how your LED panel is wired and which way up it is mounted. The LED Setup Wizard finds out without any measuring: it shows an IBM logo in up to four colours, and you pick the colour in which the logo reads upright. It handles the single 24×8 panel and the quad 4×12 panel, either way up; other arrangements get a step-by-step walkthrough.

Run it from sudo raspi-config → 0 RasQberry → Quantum Demos → LED panel → LED setup & tests → LED Setup Wizard (or sudo rq_led_setup_wizard.sh). The first-login checklist offers a short version of the same check.

The result is stored as LED_LAYOUT. On an A/B image it is kept when you update the other slot.

Accessing via raspi-config

Run sudo raspi-config and navigate to: 0 RasQberry → Quantum Demos → LED panel → Text & logos

Available Options

Option	Description
Display Custom Text	Enter text, choose mode (scroll/static/flash), and colour
Display Logo from Library	Select from pre-built logos with fade effects
Text Demos	Scrolling welcome, status messages, alert flash
Colour Effect Demos	Rainbow scroll, rainbow cycle, colour gradient
Logo Demos	IBM logo, RasQberry logo, slideshow

Command Line Usage

Display Custom Text

# Interactive text display
sudo rq_led_display_text.sh

The script prompts for:

Text to display
Mode: scroll, static, or flash
Colour: white, red, green, blue, yellow, cyan, magenta, orange

Display Logos

# Interactive logo selection
sudo rq_led_display_logo.sh

Features:

Browse pre-built logos from library
Load custom PNG/JPG images
Configurable duration and fade effects

Custom Logos

The logos ship in /usr/config/LED-Logos (ibm-logo-24x8.png, rasqberry-icon-24x8.png, rasqberry-cube-24x8.png, and 16×8 variants). To show your own image, choose Browse for custom image... in rq_led_display_logo.sh (or Display Logo from Library in the menu) and enter the path to a PNG or JPG.

Size: 24×8 pixels (width × height) fits the panel exactly; other sizes are resized automatically.
Use high-contrast images with simple shapes; fine details disappear at this resolution.

Configuration

LED settings live in /usr/config/rasqberry_environment.env. Change them with sudo raspi-config → 0 RasQberry → Advanced → Edit a RasQberry Two setting:

LED_LAYOUT - panel layout, set by the LED Setup Wizard (default: single-24x8; also quad-4x12, quad-2x2-12x4, triple-8x8, single-8x32). The LED count and matrix size follow from the layout.
LED_DEFAULT_BRIGHTNESS - default brightness 0.0-1.0 (default: 0.4); easier: Quantum Demos → LED panel → LED setup & tests → LED brightness
LED_PIXEL_ORDER - colour order of your LEDs (default: GRB)
LED_GPIO_PIN - data pin (default: 18)

LED_MATRIX_LAYOUT, LED_MATRIX_WIDTH, LED_MATRIX_HEIGHT and LED_MATRIX_Y_FLIP are deprecated and only read on old images.

Troubleshooting

Text or logo upside down or scrambled

Run the LED Setup Wizard (see above) to set LED_LAYOUT for your panel.
Try shorter text for static mode (max ~4 characters visible)

LED settings come back after a restart

The card's boot drive can hold rasqberry_boot.env (bootfs, or BOOT-A on the A/B image). Its LED_ lines are applied at every start and override the menu and the wizard: put a # in front of a line, or change it there.

Colours appear wrong

Check LED_PIXEL_ORDER setting (RGB vs GRB)
Some LEDs use a different colour order

LEDs not turning on

Make sure no other demo is still running. The panel is driven by one process at a time, so a demo left running holds it and the next one finds it busy. Stop the running demo (Quantum Demos → Stop a running LED demo), or reboot.
Run the LED test: rq_demo_run.sh led-demos led-test
Check wiring and power supply. On a Pi 5, LEDs that stop after a while mean the power supply is too weak: RasQberry says so and offers a lower brightness. Use the official 27 W supply, or lower LED panel → LED setup & tests → LED brightness.

Turn off LEDs

sudo rq_clear_leds.sh          # --stop also stops a program that holds the panel

Or use Clear All LEDs in the LED panel folder on the desktop, or Quantum Demos → LED panel → Clear All LEDs.

For developers

Python API

Four functions are the supported LED API; programs that use them keep working with later releases. Everything else in rq_led_utils is internal and may change.

from rq_led_utils import get_pixels, matrix_size, set_xy, clear_all_leds

pixels = get_pixels(brightness=0.2)  # the LED strip (one shared object)
width, height = matrix_size()        # (24, 8) on the RasQberry panels
set_xy(pixels, 0, 0, (255, 0, 0))    # top-left LED red
set_xy(pixels, width - 1, height - 1, (0, 0, 255))  # bottom-right blue
pixels.show()                        # nothing changes before show()
clear_all_leds()

Coordinates: x runs from 0 (left) to width-1, y from 0 (top) to height-1. set_xy maps them to the configured LED_LAYOUT (single-24x8 or quad-4x12, either way up), so the same program works on both kits. Positions off the panel are ignored. Avoid pixels[number]: raw numbers follow the wiring, not rows.
Run it with rq_python my_program.py. On a Pi 5, python3 in the RasQberry environment and Thonny work too; a Pi 4 needs rq_python (the LED driver needs root). Never sudo python3.
Examples: ~/My-Quantum-Programs/03_led_hello.py and 04_bell_on_leds.py.

Demo scripts

These are what the menu entries run:

Script	Description
`demo_led_text_scroll_welcome.py`	Scrolling "Welcome to RasQberry"
`demo_led_text_status.py`	Status message display
`demo_led_text_alert.py`	Flashing alert text
`demo_led_text_rainbow_scroll.py`	Rainbow-colored scrolling text
`demo_led_text_rainbow_static.py`	Static text with color cycling
`demo_led_text_gradient.py`	Text with gradient colors
`demo_led_ibm_logo.py`	Display IBM logo
`demo_led_rasqberry_logo.py`	Display RasQberry logo
`demo_led_logo_slideshow.py`	Cycle through all logos

Example:

rq_python /usr/bin/demo_led_ibm_logo.py

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