Leddy

Leddy displays customizable pixelly goodness and information on a Unicorn Hat HD (or Ubercorn Hat) for the Raspberry Pi.

Video demonstration

A small video demonstrating the features of Leddy as of February 9th 2021 using an Ubercorn LED matrix can be seen here. I've built a frame using the instructions seen here with a slight variation in the four spacer blocks to better hold the Ubercorn in place. All STL files can be found in the stl subfolder.

The scene rotation and look of each scene is easily customizable through just one XML file per theme. A default theme is provided with the software to get you started in no time.

Leddy supports the following features:

• Animations (PNG sprite sheet or animated GIF)
• Chroma-keyed transitions (PNG sprite sheet or animated GIF)
• Weather (using OpenWeatherMap API)
• Time / Date
• Rss feed headlines / titles as scrolling text
• Conway's "Game of Life"
• Run terminal commands and display output on LED matrix
• Scrolling image gallery

The general configuration of Leddy is handled through the config.ini file. It is created in the same folder as the executable when you run Leddy for the first time. You might want to fiddle with the following settings:

[theme]
xml=themes/default.xml

[unicorn_hd]
brightness=50
framerate=30
rotation=180

But the fun stuff happens in the themes subfolder. In here you can create your own theme for use with the LED matrix. A theme consists of a single XML file with theme definitions and a folder that contains all of the theme resources. To use your own theme XML file simply set it in config.ini:

[theme]
xml=themes/yourowntheme.xml

Read more on how to customize a theme XML file here.

Prerequisites

Hardware

• Raspberry Pi
• Unicorn Hat HD or Ubercorn hat (they are the same, just very different sizes)

Software

You need to enable the Raspberry Pi SPI interface. This can be easily done by editing /boot/config.txt and uncommeing the line #rdtparam=spi=on (by removing the #). Save the file and reboot the pi for the change to take effect.

You also need to install Qt5 and libgif:

$ sudo apt-get update
$ sudo apt-get install build-essential qtbase5-dev libgif-dev

Compile

Clone or download the code from this repository and run the commands to compile Leddy. The commands need to be run from the base folder where the leddy.pro file resides.

Without Unicorn Hat HD simulator

$ qmake
$ make clean
$ make

With Unicorn Hat HD simulator

Leddy includes a Unicorn Hat HD simulator which shows the LED's as pixels in a window on you desktop. Note that this requires a windowing system to work. This is useful while customizing your theme, if you want to run it on a non-Pi system. When it's running you can resize the simulator window with the mouse scroll-wheel.

$ qmake WITHSIM=1
$ make clean
$ make

Running

$ ./Leddy

Running as a service

I like to run Leddy as a service using systemd. This enables it to auto-start when I boot the Raspberry Pi. I've provided a very simple systemd service file you can use to run it as a service. It's located under systemd/leddy.service. All you need to do is copy that file to /etc/systemd/system/leddy.service and edit the ExecStart path and executable to wherever your compiled Leddy executable is located. If you want to run Leddy with a different user than the pi user and group, you can also change that. Then run the following to reload the systemd services and enable it upon next reboot:

$ sudo systemctl daemon-reload
$ sudo systemctl enable leddy

If you don't want to reboot, you can start the service manually with:

$ sudo systemctl start leddy

And that's it! If you have the Unicorn Hat HD or Ubercorn Hat installed, it should start running on it.

Version 1.0.1 (In progress, unreleased):

• Added 'gallery' scene type
• Now uses EasyGifReader (MIT License) by Viktor Chlumsky which in turn uses gif_lib
• Fixed config framerate to be a framerate rather than a frametime
• Now uses MATRIX::WIDTH and MATRIX::HEIGHT constexpr for all matrix dimension manipulations

Version 1.0.0 (Unreleased):

• First code upload to the public