RGBMatrixEmulator

RGBMatrixEmulator is a Python package for emulating RGB LED matrices that are normally driven by the rpi-rgb-led-matrix library. Most commonly, these are used with single-board computers such as the Raspberry Pi.

RGBMatrixEmulator (currently) supports a subset of the function calls present in the Python bindings for rpi-rgb-led-matrix. As such, it's accuracy is not 100% guaranteed.

Installation

RGBMatrixEmulator is in the Python Package Index (PyPI). Installing with pip is recommended for all systems.

pip install RGBMatrixEmulator

Usage

Projects that are able to be emulated will rely on importing classes from rpi-rgb-led-matrix. These will need to be replaced by equivalent RGBMatrixEmulator classes.

For example, usage on a Rasberry Pi might look like this:

from rgbmatrix import RGBMatrix, RGBMatrixOptions

The emulated version will need to use RGBMatrixEmulator classes:

from RGBMatrixEmulator import RGBMatrix, RGBMatrixOptions

After this, most of the existing command line arguments from the rpi-rgb-led-matrix library still apply. You should reference the project README for that library when necessary.

Startup of the existing script will be unchanged.

Customization

The first time you run a script with the emulator enabled, a file called emulator_config.json will be created in the script's directory. This enables configurations to be customized on a per-script basis. If you would like to regenerate the default configuration, you can delete the file and a new one will be created the next time the emulator starts.

The default configuration is as follows:

{
  "pixel_outline": 0,
  "pixel_size": 16,
  "pixel_style": "square",
  "display_adapter": "browser",
  "suppress_font_warnings": false,
  "suppress_adapter_load_errors": false,
  "browser": {
    "_comment": "For use with the browser adapter only.",
    "port": 8888,
    "target_fps": 24,
    "fps_display": false,
    "quality": 70,
    "image_border": true,
    "debug_text": false,
    "image_format": "JPEG"
  },
  "log_level": "info"
}

Configuration Options

pixel_outline          (Integer): Size of the black border around each pixel. Only works on some adapters; others will ignore this configuration.
pixel_size             (Integer): Size of the emulated LED. Helpful for emulating large matrices on small screens. Actual window size is the matrix size scaled by pixel size.
pixel_style            (String):  Style of the emulated LED. Supported pixel styles are "square" and "circle". Some display adapters do not support all options and will revert to a supported style.
display_adapter        (String):  Display adapter for the emulator. See Display Adapters section for details.
suppress_font_warnings (Boolean): Suppress BDF font parsing errors, such as for missing characters.
browser                (Dict):    Additional configuration options for the "browser" display adapter. Does nothing for other adapters.
  port                 (Integer): Port for the rendering server to attach to. Example: http://localhost:8888
  target_fps           (Integer): Target frames per second. Higher values may lead to lower performance.
  fps_display          (Bool):    Display the FPS.
  quality              (Intger):  Value from 0 - 100 indicating the quality percentage for the rendered image. Higher values may lead to lower performance.
  image_border         (Bool):    Display a slight border around the rendered image.
  debug_text           (Bool):    Display debug text.

Altering the pixel_size configuration will change how large the LEDs appear on your screen. This is helpful for emulating large matrices or on small screens.

You can also change the pixel_style option. By default, the emulator represents LEDs as squares. If you prefer the LEDs to have a more rounded appearance (like they would on an actual matrix), you can change to pixel_style: "circle".

Display Adapters

By default, RGBMatrixEmulator uses browser as its display adapter for maximum compatibility with different operating systems as well as thread-safety. However, you can also use other display adapters as well if the default adapter does not suit your needs.

Currently supported display adapters are:

• browser (default)
• pygame
• terminal
• tkinter
• turtle
• sixel

You can swap display adapters by changing the display_adapter value to one of the above in emulator_config.json.

Note: Not all display adapters support all emulator features. Some adapters may require additional setup steps to install. For example, on OSX, it may be necessary to install tkinter via Homebrew (brew install python-tk).

Browser Display Adapter

Please see the README for the browser display adapter for further information regarding its configuration and usage.

Screenshots

Samples

See Samples README for more information about running example scripts.

Known Issues

• Calling draw functions on an instance of RGBMatrix is slow (i.e. matrix.SetPixel, matrix.Fill)

  • Prefer using on a Canvas instance instead

  • rpi-rgb-led-matrix uses a threaded implementation to handle single pixel draws with the RGBMatrix class, unfortunately RGBMatrixEmulator redraws the entire screen on each call

  • NOTE: the implementation is accurate other than speed (you can still drop RGBMatrixEmulator into a project that makes calls to the matrix object)

  • Expand Example

    # SLOW
    matrix = RGBMatrix(options = RGBMatrixOptions)
    
    for y in matrix.height:
      for x in matrix.width:
        matrix.SetPixel(x, y, 255, 255, 255) # Redraws entire screen
    
    # FAST
    matrix = RGBMatrix(options = RGBMatrixOptions)
    canvas = matrix.CreateFrameCanvas()
    
    for y in matrix.height:
      for x in matrix.width:
        canvas.SetPixel(x, y, 255, 255, 255) # No redraw
    
    matrix.SwapOnVsync(canvas) # Force screen refresh

• Drawing large strings is slow, partly because of the linelimit parameter in the BDF font parser this emulator uses to prevent multiline text from being rendered unintentionally.

Contributing

If you want to help develop RGBMatrixEmulator, you must also install the dev dependencies, which can be done by running pip install -e .[dev] from within the directory.

Before submitting a PR, please open an issue to help us track development. All development should be based off of the dev branch. This branch is kept up-to-date with main after releases.

Contact

Tyler Porter

tyler.b.porter@gmail.com