Build a Magical LED Fire Lantern with Raspberry Pi

Create an Enchanting Animated Prop for Theater or Home Decor

Why build this? After purchasing an RGB LED Matrix, I
wanted to create something truly special. When our amateur theater
needed a "magically extinguishable" medieval lantern (controlled via
WiFi), the perfect project emerged!

Why Build This?

As a developer who loves mixing tech with creativity, I wanted to make something special with my new RGB LED matrix.

When our amateur theater needed a "magically extinguishable" medieval lantern, the perfect project emerged!

Hardware Shopping List

Core Electronics:

Raspberry Pi (Model 3B+ or newer recommended) | ~$45

Adafruit 64x32 RGB LED Matrix (4mm Pitch) | ~$40

Adafruit RGB Matrix Bonnet | ~$15

5V 10A Power Supply (e.g., LEICKE NT30538) | ~$41

Enclosure Components:

Raspberry Pi case compatible with Matrix Bonnet | ~$14

Medieval-style lantern housing (I used a €20 HOME decor piece)

White plexiglass for light diffusion | ~€10 / $11

Total Cost: ~€166 / $187

Hardware Setup: Installing the RGB Matrix Bonnet

Adafruit's excellent installation guide makes this straightforward:


curl https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/rgb-matrix.sh >rgb-matrix.sh
sudo bash rgb-matrix.sh

Pro Tip: The Matrix Bonnet can power your Pi! With a robust 5V supply, you'll need only one power cable for the entire setup.

Software Installation: Bringing the Fire to Life

Using a custom Node.js application implementing the classic "Doom Fire" algorithm, which is described in this good post by Fabien Sanglard.

My code is heavily inspired from that random python gist I found somewhere in the web.

Here’s how you install everything:


# Install Node 12.x from NodeSource
curl -sL https://deb.nodesource.com/setup_12.x | sudo bash -
sudo apt-get install -y nodejs
node --version

# Install yarn package manager
curl -sL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update && sudo apt-get install yarn

# Install pm2
sudo npm install pm2 -g

# Install rpi-led-matrix-fire
wget https://github.com/Fensterbank/rpi-led-matrix-fire/releases/download/1.1.0/rpi-led-matrix-fire_1.1.0.tar.gz
tar -zxf rpi-led-matrix-fire_1.1.0.tar.gz
cd rpi-led-matrix-fire
yarn install

# Test the fire
sudo su
./bin/run --help
./bin/run -p

The last commands was the rpi-led-matrix-fire script, which comes with a few command-line options:

command-line options for rpi-led-matrix-fire

In my case I wanted to rotate the fire by 270 degrees, but based on your case you may want it in another orientation.

Key Parameter: --led-slowdown-gpio (values 0-4) - Adjust based on your Pi's performance using hzeller's documentation.

If you followed these steps, you should see the working fire on your LED Matrix. Hurray! 🎉

Automated Operation: Keep the Fire Burning

Using PM2 process manager for reliability:

Create ecosystem.config.js:


module.exports = {
  apps : [{
    name: 'LED Fire',
    script: './bin/run -t 270',
    cwd: './rpi-led-matrix-fire',
    instances: 1,
    autorestart: true,
    watch: true,
    watch_delay: 5000,
    ignore_watch: ['node_modules', '.git'],
  }],
};

Enable persistent operation:


# write init configuration to make pm2 startup on boot
pm2 startup

# start the ecosystem
pm2 start ecosystem.config.js

# save the current process list 
pm2 save

Troubleshooting: Use pm2 log to view real-time outputs if issues arise.

Sometimes the script is crashing due to driver issues, but pm2 will restart it again.

Lantern Assembly: From Tech to Theater Prop

From a technical side we are now finished.

All you need to do is to build (or buy) a lantern case and insert your tech stuff there.

☝️

Confession: I’m a freelance full stack web developer, not a carpenter. I have achieved my goal, but I probably did not use the right tools for the right purposes. Please excuse me. 🤷‍