rpi-rgb-led-matrix/utils

Utilities

This contains useful utilities that might be directly useful without having to write any code.

Image Viewer

The image viewer reads all kinds of image formats, including animated gifs. To compile, you first need to install the GraphicsMagick dependencies first:

sudo apt-get update
sudo apt-get install libgraphicsmagick++-dev libwebp-dev -y
make led-image-viewer

The resulting binary has a couple of flags.

usage: ./led-image-viewer [options] <image> [<image> ...]
Options:
        -C                        : Center images.
        -w<seconds>               : If multiple images given: Wait time between in seconds (default: 1.5).
        -f                        : Forever cycle through the list of files on the command line.
        -t<seconds>               : For gif animations: stop after this time.
        -l<loop-count>            : For gif animations: number of loops through a full cycle.
        -L                        : Large display, in which each chain is 'folded down'
                                    in the middle in an U-arrangement to get more vertical space.
        -R<angle>                 : Rotate output; steps of 90 degrees

General LED matrix options:
        --led-rows=<rows>         : Panel rows. 8, 16, 32 or 64. (Default: 32).
        --led-chain=<chained>     : Number of daisy-chained panels. (Default: 1).
        --led-parallel=<parallel> : For A/B+ models or RPi2,3b: parallel chains. range=1..3 (Default: 1).
        --led-pwm-bits=<1..11>    : PWM bits (Default: 11).
        --led-brightness=<percent>: Brightness in percent (Default: 100).
        --led-scan-mode=<0..1>    : 0 = progressive; 1 = interlaced (Default: 0).
        --led-show-refresh        : Show refresh rate.
        --led-inverse             : Switch if your matrix has inverse colors on.
        --led-swap-green-blue     : Switch if your matrix has green/blue swapped on.
        --led-pwm-lsb-nanoseconds : PWM Nanoseconds for LSB (Default: 130)
        --led-no-hardware-pulse   : Don't use hardware pin-pulse generation.
        --led-slowdown-gpio=<0..2>: Slowdown GPIO. Needed for faster Pis and/or slower panels (Default: 1).
        --led-daemon              : Make the process run in the background as daemon.
        --led-no-drop-privs       : Don't drop privileges from 'root' after initializing the hardware.
Switch time between files: -w for static images; -t/-l for animations
Animated gifs: If both -l and -t are given, whatever comes first determines duration.

Then, you can run it with any common image format, including animated gifs:

Examples:

sudo ./led-image-viewer some-image.jpg       # Display an image.
sudo ./led-image-viewer animated.gif         # Show an animated gif
sudo ./led-image-viewer -t5 animated.gif     # Show an animated gif for 5 seconds
sudo ./led-image-viewer -l2 animated.gif     # Show an animated gif for 2 loops

sudo ./led-image-viewer    -w3 foo.jpg bar.png  # show two images, wait 3 seconds between. Stop.
sudo ./led-image-viewer -f -w3 foo.jpg bar.png  # show images, wait 3sec between, go back and loop forever

sudo ./led-image-viewer -f -w3 *.png *.jpg   # Loop forever through a list of images

# Show image.png and animated.gif in a loop. Show the static image for 3 seconds
# while the animation is shown for 5 seconds (-t takes precendence for animated
# images over -w)
sudo ./led-image-viewer -f -w3 -t5 image.png animated.gif

It also supports the standard options to specify the connected displays (e.g. --led-rows, --led-chain, --led-parallel and all other led-libray flags)