In CCCB, there is a big pixel matrix hanging on the wall. It is called "Service Point Display" or "Airport Display". This repository contains a library for parsing, encoding and sending packets to this display via UDP in multiple programming languages.
Take a look at the contained crates for language specific information:
Language | Readme |
---|---|
Rust | servicepoint |
C / C++ | servicepoint_binding_c |
C# / F# | servicepoint_binding_cs |
- screen simulator (rust): servicepoint-simulator
- tanks game (C#): servicepoint-tanks
- cellular automata slideshow (rust): servicepoint-life
To add yourself to the list, open a pull request.
- Resolution: 352x160=56,320 pixels
- Pixels are grouped into 44x20=880 tiles (8x8=64 pixels each)
- Smallest addressable unit: row of pixels inside of a tile (8 pixels = 1 byte)
- The brightness can only be set per tile
- Screen content can be changed using a simple UDP protocol
- Between each row of tiles, there is a gap of around 4 pixels size. This gap changes the aspect ratio of the display.
A UDP package sent to the display has a header size of 10 bytes. Each header value has a size of two bytes (unsigned 16 bit integer). Depending on the command, there can be a payload following the header.
The commands are implemented in DisplayCommands.
To change screen contents, these commands are the most relevant:
- Clear screen
- command:
0x0002
- (rest does not matter)
- command:
- Send CP437 data: render specified text into rectangular region
- command:
0x0003
- top left tile x
- top left tile y
- width in tiles
- height in tiles
- payload: (width in tiles * height in tiles) bytes
- 1 byte = 1 character
- each character is rendered into one tile (mono-spaced)
- characters are encoded using code page 437
- command:
- Send bitmap window: set pixel states for a rectangular region
- command:
0x0013
- top left tile x
- top left pixel y
- width in tiles
- height in pixels
- payload: (width in tiles * height in pixels) bytes
- network byte order
- 1 bit = 1 pixel
- command:
There are other commands implemented as well, e.g. for changing the brightness.
After servicepoint2
has been merged into servicepoint
, servicepoint2
will not continue to get any updates.
Contributions are accepted in any form (issues, documentation, feature requests, code, review, ...).
All creatures welcome.