LED Matrix Clock

A simple, modular clock application for Raspberry Pi using Adafruit LED Matrix displays.

Hardware Requirements

• Raspberry Pi 3
• 2x Adafruit 64x32 LED Matrices
• Adafruit Pi LED Matrix Bonnet

Installation

1. Install required system packages:

sudo apt-get update
sudo apt-get install -y python3-pip python3-dev python3-setuptools
sudo apt-get install -y build-essential git
sudo apt-get install -y python3-pil python3-pil.imagetk
sudo apt-get install -y cython3

2. Install the rpi-rgb-led-matrix library and Python bindings:

# Make sure you're in the main project directory
cd ~/LEDSportsMatrix/rpi-rgb-led-matrix-master

# Build the C++ library first
make

# Build and install Python bindings
cd bindings/python
sudo python3 setup.py install
cd ../..

# Install the library files
sudo cp -r lib/* /usr/local/lib/
sudo cp -r include/* /usr/local/include/
sudo ldconfig
cd ..

3. Install additional Python packages:

sudo python3 -m pip install pytz

4. Install the DejaVu Sans font:

sudo apt-get install -y fonts-dejavu

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. Save and reboot:

sudo reboot

Configuration

Edit the config/config.json file to customize:

• Timezone
• Display settings (brightness, dimensions)
• Clock format and update interval

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

Important: Sound Module Configuration

The LED matrix library is known to conflict with the Raspberry Pi's built-in sound module. To prevent issues:

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

Note: If you still experience issues, you can additionally disable the audio hardware by editing /boot/firmware/config.txt:

sudo nano /boot/firmware/config.txt

And adding:

dtparam=audio=off

Alternatively, you can:

• Use external USB sound adapters if you need audio
• Run the program with --led-no-hardware-pulse flag (may cause more flicker)

Running the Clock

The program must be run with root privileges to access the LED matrix hardware:

cd src
sudo python3 display_controller.py

To stop the clock, press Ctrl+C.

Project Structure

• src/
  • clock.py - Main clock application
  • config_manager.py - Configuration management
  • display_manager.py - LED matrix display handling
• config/
  • config.json - Configuration settings
  • config_secrets.json - Private settings (not in git)