Custom LED Matrix

I’m currently working on this project. The aim is to create a billboard-style LED matrix that can display images, text, and animations – think digital signage, but built from scratch with addressable LEDs.

Project Overview

At the moment, the matrix comprises 10 rows of 90 LEDs each – that’s 900 individually addressable pixels. The plan is to expand this to at least 20 rows (1,800 total LEDs) for better resolution and more complex displays.

The current stopping point is figuring out how to mount the LED strips to a fixed surface. I’ve experimented with corflute (corrugated plastic), but the readily available sheets are too thin to provide adequate support for the strips and wiring.

Parts List

• LED Strips: WS2811b LED Strip (5V) – 30 LEDs per metre works well for this project
• Controller: NodeMCU with OLED – handles the LED data and provides a simple interface
• Firmware: WLED – excellent open-source software for LED control
• Sequencing Software: xLights – create animations and sync to music
• Power Supply: 5V power brick (aim for 30-50% headroom – 900 LEDs at full white can draw 50A+)
• Mounting Surface: Still experimenting – PVC sheets, aluminium composite panel, or custom 3D-printed holders

Build Process

Step 1: Planning the Matrix

Decide on your resolution. For text, you’ll want at least 5 pixels per character height for readability. For images, more is better – but each pixel adds complexity, power draw, and processing load.

Step 2: Mounting the Strips

This is the tricky part. The strips need to be perfectly straight and evenly spaced for a clean display. I’ve tried:

• Corflute: Cheap and available at Bunnings, but too flimsy for larger matrices
• PVC foam board: Better rigidity, still experimenting
• Aluminium composite panel: Professional option – lightweight, rigid, but more expensive

Step 3: Wiring

Each strip needs power at both ends (power injection) to prevent voltage drop, especially with 5V strips. The data line snakes from one strip to the next in a zigzag pattern.

Step 4: Configuration

In WLED, configure the LED count and layout to match your physical arrangement. The “2D” settings let you define rows and columns so effects render correctly.

xLights Integration

For more advanced sequencing (especially syncing to music), xLights is the industry standard. You can create custom models that match your matrix dimensions, design animations, and schedule shows.

WLED can receive data from xLights via E1.31 (DMX over network), allowing real-time control from your sequencing software.

Pro Tips

• Start smaller than you think: 900 LEDs is already pushing the limits of a single NodeMCU. For 1,800+, consider an ESP32 or dedicated LED controller.
• Power is critical: Undersized power supplies cause flickering and resets. Always plan for 50% more than your calculated maximum.
• Test early, test often: Don’t mount everything before testing. Power up sections as you go to catch wiring issues early.
• Weatherproofing: If this will be outdoors, buy IP65+ rated strips and seal all connections with heat shrink or silicone.

Next Steps

I’ll update this post once I’ve solved the mounting challenge and expanded to the full 20-row matrix. The goal is to have it ready for next Christmas season – watch this space!

In the meantime, check out the LED Tunnel and LED Star projects for similar builds with addressable LEDs.