LEDMatrix

A modular LED matrix display system for sports information using Raspberry Pi and RGB LED matrices.

Work in Progress, things may break. I'll try to keep the main branch as stable as I can but this is absolutely in a pre-release state. There are also a ton of commits as it's an easy way to get the changes to the rpi for testing.

Hardware Requirements

• Raspberry Pi 4 or older
• Adafruit RGB Matrix Bonnet/HAT
• 2x LED Matrix panels (64x32)
• DC Power Supply for Adafruit RGB HAT

Installation

1. Clone this repository:

git clone https://github.com/ChuckBuilds/LEDMatrix.git
cd LEDMatrix

2. Install dependencies:

pip3 install --break-system-packages -r requirements.txt

--break-system-packages allows us to install without a virtual environment

Configuration

1. Copy the example configuration:

cp config/config.example.json config/config.json

2. Edit config/config.json with your preferences

Important: Sound Module Configuration

1. Remove unnecessary services that might interfere with the LED matrix:

sudo apt-get remove bluez bluez-firmware pi-bluetooth triggerhappy pigpio

2. Blacklist the sound module:

cat <<EOF | sudo tee /etc/modprobe.d/blacklist-rgb-matrix.conf
blacklist snd_bcm2835
EOF

sudo update-initramfs -u

3. Reboot:

sudo reboot

Performance Optimization

To reduce flickering and improve display quality:

1. Edit /boot/firmware/cmdline.txt:

sudo nano /boot/firmware/cmdline.txt

2. Add isolcpus=3 at the end of the line

3. Add dtparam=audio=off at the end of the line

4. Ctrl + X to exit, Y to save

5. Save and reboot:

sudo reboot

Running without Sudo (Optional and not recommended)

To run the display script without sudo, the user executing the script needs access to GPIO pins. Add the user to the gpio group:

sudo usermod -a -G gpio <your_username>
# Example for user 'ledpi':
# sudo usermod -a -G gpio ledpi

Important: You must reboot the Raspberry Pi after adding the user to the group for the change to take effect.

You also need to disable hardware pulsing in the code (see src/display_manager.py, set options.disable_hardware_pulsing = True). This may result in a flickerying display

If configured correctly, you can then run:

python3 display_controller.py

Running the Display

From the project root directory:

sudo python3 display_controller.py

The display will alternate between showing:

• Current time
• Weather information (requires API key configuration)

Systemd Service Installation

The LEDMatrix can be installed as a systemd service to run automatically at boot and be managed easily. The service runs as root to ensure proper hardware timing access for the LED matrix.

Installing the Service

1. Make the install script executable:

chmod +x install_service.sh

2. Run the install script with sudo:

sudo ./install_service.sh

The script will:

• Detect your user account and home directory
• Install the service file with the correct paths
• Enable the service to start on boot
• Start the service immediately

Managing the Service

The following commands are available to manage the service:

# Stop the display
sudo systemctl stop ledmatrix.service

# Start the display
sudo systemctl start ledmatrix.service

# Check service status
sudo systemctl status ledmatrix.service

# View logs
journalctl -u ledmatrix.service

# Disable autostart
sudo systemctl disable ledmatrix.service

# Enable autostart
sudo systemctl enable ledmatrix.service

Convenience Scripts

Two convenience scripts are provided for easy service management:

• start_display.sh - Starts the LED matrix display service
• stop_display.sh - Stops the LED matrix display service

Make them executable with:

chmod +x start_display.sh stop_display.sh

Then use them to control the service:

sudo ./start_display.sh
sudo ./stop_display.sh

API Keys

For sensitive settings like API keys:

1. Copy the template: cp config/config_secrets.template.json config/config_secrets.json

2. Edit config/config_secrets.json with your API keys via sudo nano config/config_secrets.json

3. Ctrl + X to exit, Y to overwrite, Enter to save

NHL, NBA, MLB Scoreboard Display

The LEDMatrix system includes a comprehensive NHL, NBA scoreboard display system with three display modes:

Display Modes

• Live Games: Shows currently playing games with live scores and game status
• Recent Games: Displays completed games from the last 48 hours (configurable)
• Upcoming Games: Shows scheduled games for favorite teams

Features

• Real-time score updates from ESPN API
• Team logo display
• Game status indicators (period, time remaining)
• Power play and penalty information
• Configurable favorite teams
• Automatic game switching
• Built-in caching to reduce API calls
• Test mode for development

Configuration

In config.json, under the nhl_scoreboard section:

{
    "nhl_scoreboard": {
        "enabled": true,
        "test_mode": false,
        "update_interval_seconds": 300,
        "live_update_interval": 60,
        "recent_update_interval": 1800,
        "upcoming_update_interval": 1800,
        "recent_game_hours": 48,
        "favorite_teams": ["TB", "DAL"],
        "logo_dir": "assets/sports/nhl_logos",
        "display_modes": {
            "nhl_live": true,
            "nhl_recent": true,
            "nhl_upcoming": true
        }
    }
}

YouTube Display Configuration

The YouTube display module shows channel statistics for a specified YouTube channel. To configure it:

1. In config/config.json, add the following section:

{
    "youtube": {
        "enabled": true,
        "update_interval": 300  // Update interval in seconds (default: 300)
    }
}

2. In config/config_secrets.json, add your YouTube API credentials:

{
    "youtube": {
        "api_key": "YOUR_YOUTUBE_API_KEY",
        "channel_id": "YOUR_CHANNEL_ID"
    }
}

To get these credentials:

1. Go to the Google Cloud Console
2. Create a new project or select an existing one
3. Enable the YouTube Data API v3
4. Create credentials (API key)
5. For the channel ID, you can find it in your YouTube channel URL or use the YouTube Data API to look it up

Calendar Display Configuration

The calendar display module shows upcoming events from your Google Calendar. To configure it:

1. In config/config.json, add the following section:

{
    "calendar": {
        "enabled": true,
        "update_interval": 300,  // Update interval in seconds (default: 300)
        "max_events": 3,         // Maximum number of events to display
        "calendars": ["primary"] // List of calendar IDs to display
    }
}

2. Set up Google Calendar API access:

   1. Go to the Google Cloud Console
   2. Create a new project or select an existing one
   3. Enable the Google Calendar API
   4. Create OAuth 2.0 credentials:
      • Application type: Desktop app
      • Download the credentials file as credentials.json
   5. Place the credentials.json file in your project root directory

3. On first run, the application will:

   • Open a browser window for Google authentication
   • Request calendar read-only access
   • Save the authentication token as token.pickle

The calendar display will show:

• Event date and time
• Event title (wrapped to fit the display)
• Up to 3 upcoming events (configurable)

Development

The project structure is organized as follows:

LEDMatrix/
├── config/                 # Configuration files
│   ├── config.json         # Main configuration
│   └── config_secrets.json # API keys and sensitive data
├── src/                    # Source code
│   ├── config_manager.py   # Configuration loading
│   ├── display_manager.py  # LED matrix display handling
│   ├── clock.py            # Clock display module
│   ├── weather_manager.py  # Weather display module
│   ├── stock_manager.py    # Stock ticker display module
│   └── stock_news_manager.py # Stock news display module
└── display_controller.py   # Main application controller

Project Structure

• src/
  • display_controller.py - Main application controller
  • config_manager.py - Configuration management
  • display_manager.py - LED matrix display handling
  • clock.py - Clock display module
  • weather_manager.py - Weather display module
  • stock_manager.py - Stock ticker display module
  • stock_news_manager.py - Stock news display module
• config/
  • config.json - Configuration settings
  • config_secrets.json - Private settings (not in git)

Caching System

The LEDMatrix system includes a robust caching mechanism to optimize API calls and reduce network traffic:

Cache Location

• Default cache directory: /tmp/ledmatrix_cache
• Cache files are stored with proper permissions (755 for directories, 644 for files)
• When running as root/sudo, cache ownership is automatically adjusted to the real user

Cached Data Types

• Weather data (current conditions and forecasts)
• Stock prices and market data
• Stock news headlines
• NHL game information
• NBA game information

Cache Behavior

• Data is cached based on update intervals defined in config.json
• Cache is automatically invalidated when:
  • Update interval has elapsed
  • Market is closed (for stock data)
  • Data has changed significantly
• Failed API calls fall back to cached data when available
• Cache files use atomic operations to prevent corruption

Cache Management

• Cache files are automatically created and managed
• No manual intervention required
• Cache directory is created with proper permissions on first run
• Temporary files are used for safe updates
• JSON serialization handles all data types including timestamps

Fonts

You can add any font to the assets/fonts/ folder but they need to be .ttf and updated in display_manager.py

Music Display Configuration

The Music Display module shows information about the currently playing track from either Spotify or YouTube Music (via the YouTube Music Desktop App companion server).

Setup Requirements:

1. Spotify:

   • Requires a Spotify Premium account (for API access).
   • You need to register an application on the Spotify Developer Dashboard to get API credentials.
     • Go to the dashboard, log in, and click "Create App".
     • Give it a name (e.g., "LEDMatrix Display") and description.
     • For the "Redirect URI", enter http://127.0.0.1:8888/callback (or another unused port if 8888 is taken). You must add this exact URI in your app settings on the Spotify dashboard.
     • Note down the Client ID and Client Secret.

2. YouTube Music (YTM):

   • Requires the YouTube Music Desktop App (YTMD) to be installed and running on a computer on the same network as the Raspberry Pi.
   • In YTMD settings, enable the "Companion Server" under Integration options. Note the URL it provides (usually http://localhost:9863 if running on the same machine, or http://<YTMD-Computer-IP>:9863 if running on a different computer).

Configuration:

1. In config/config_secrets.json, add your Spotify API credentials under the music key:

   {
       "music": {
           "SPOTIFY_CLIENT_ID": "YOUR_SPOTIFY_CLIENT_ID_HERE",
           "SPOTIFY_CLIENT_SECRET": "YOUR_SPOTIFY_CLIENT_SECRET_HERE",
           "SPOTIFY_REDIRECT_URI": "http://127.0.0.1:8888/callback" 
       }
       // ... other secrets ...
   }
   

   (Ensure the SPOTIFY_REDIRECT_URI here matches exactly what you entered in the Spotify Developer Dashboard).

2. In config/config.json, add/modify the music section:

   {
       "music": {
           "enabled": true, // Set to false to disable this display
           "preferred_source": "auto", // Options: "auto", "spotify", "ytm"
           "YTM_COMPANION_URL": "http://<YTMD-Computer-IP>:9863", // Replace with actual URL if YTMD is not on the Pi
           "POLLING_INTERVAL_SECONDS": 2 // How often to check for track updates
       }
       // ... other configurations ...
   }
   

   Also, ensure the display duration is set in the display_durations section:

   {
       "display": {
           "display_durations": {
               "music": 20, // Duration in seconds
               // ... other durations ...
           }
       }
       // ... other configurations ...
   }
   

preferred_source Options:

• "auto": (Default) Checks Spotify first. If Spotify is playing, shows its track. If not, checks YTM.
• "spotify": Only uses Spotify. Ignores YTM.
• "ytm": Only uses the YTM Companion Server. Ignores Spotify.

Spotify Authentication for Music Display

If you are using the Spotify integration to display currently playing music, you will need to authenticate with Spotify. This project uses an authentication flow that requires a one-time setup. Due to how the display controller script may run with specific user permissions (even when using sudo), the following steps are crucial:

1. Initial Setup & Secrets:

   • Ensure you have your Spotify API Client ID, Client Secret, and Redirect URI.
   • The Redirect URI should be set to http://127.0.0.1:8888/callback in your Spotify Developer Dashboard.
   • Copy config/config_secrets.template.json to config/config_secrets.json.
   • Edit config/config_secrets.json and fill in your Spotify credentials under the "music" section:

     {
       "music": {
         "SPOTIFY_CLIENT_ID": "YOUR_SPOTIFY_CLIENT_ID",
         "SPOTIFY_CLIENT_SECRET": "YOUR_SPOTIFY_CLIENT_SECRET",
         "SPOTIFY_REDIRECT_URI": "http://127.0.0.1:8888/callback"
       }
     }
     

2. Run the Authentication Script:

   • Execute the authentication script using sudo. This is important because it needs to create an authentication cache file (spotify_auth.json) that will be owned by root.

     sudo python3 src/authenticate_spotify.py
     

   • The script will output a URL. Copy this URL and paste it into a web browser on any device.
   • Log in to Spotify and authorize the application.
   • Your browser will be redirected to a URL starting with http://127.0.0.1:8888/callback?code=.... It will likely show an error page like "This site can't be reached" – this is expected.
   • Copy the entire redirected URL from your browser's address bar.
   • Paste this full URL back into the terminal when prompted by the script.
   • If successful, it will indicate that token info has been cached.

3. Adjust Cache File Permissions:

   • The main display script (display_controller.py), even when run with sudo, might operate with an effective User ID (e.g., UID 1 for 'daemon') that doesn't have permission to read the spotify_auth.json file created by root (which has -rw------- permissions by default).
   • To allow the display script to read this cache file, change its permissions:

     sudo chmod 644 config/spotify_auth.json
     

   This makes the file readable by all users, including the effective user of the display script.

4. Run the Main Application:

   • You should now be able to run your main display controller script using sudo:

     sudo python3 display_controller.py
     

   • The Spotify client should now authenticate successfully using the cached token.

Why these specific permissions steps?

The authenticate_spotify.py script, when run with sudo, creates config/spotify_auth.json owned by root. If the main display_controller.py (also run with sudo) effectively runs as a different user (e.g., UID 1/daemon, as observed during troubleshooting), that user won't be able to read the root-owned file unless its permissions are relaxed (e.g., to 644). The chmod 644 command allows the owner (root) to read/write, and everyone else (including the daemon user) to read.

Music Display (YouTube Music)

The system can display currently playing music information from YouTube Music Desktop (YTMD) via its Companion server API.

Setup:

1. Enable Companion Server in YTMD:

   • In the YouTube Music Desktop application, go to Settings -> Integrations.
   • Enable the "Companion Server".
   • Note the IP address and Port it's listening on (default is usually http://localhost:9863), you'll need to know the local ip address if playing music on a device other than your rpi (probably are).

2. Configure config/config.json:

   • Update the music section in your config/config.json:

     "music": {
         "enabled": true,
         "preferred_source": "ytm",
         "YTM_COMPANION_URL": "http://YOUR_YTMD_IP_ADDRESS:PORT", // e.g., "http://localhost:9863" or "http://192.168.1.100:9863"
         "POLLING_INTERVAL_SECONDS": 1
     }
     

3. Initial Authentication & Token Storage:

   • The first time you run python3 src/authenticate_ytm.py after enabling YTM, it will attempt to register itself with the YTMD Companion Server.
   • You will see log messages in the terminal prompting you to approve the "LEDMatrixController" application within the YouTube Music Desktop app. You typically have 30 seconds to do this.
   • Once approved, an authentication token is saved to your config/ytm_auth.json.
   • This ensures the ledpi user owns the config directory and file, and has the necessary write permissions.

Troubleshooting:

• "No authorized companions" in YTMD: Ensure you've approved the LEDMatrixController in YTMD settings after the first run.
• Connection errors: Double-check the YTM_COMPANION_URL in config.json matches what YTMD's companion server is set to.