Skip to content

Latest commit

 

History

History
70 lines (61 loc) · 2.35 KB

DESIGN.md

File metadata and controls

70 lines (61 loc) · 2.35 KB

Infoscreen Design Specification

Conceptual Overview

An embedded system will be attached to a public display screen (TFT or LCD). The embedded system dynamically serves HTML pages via X and a Browser. The browser is automated using the Webdriver Framework [0] implementation of Selenium [1]. New content MUST be pushed onto the device via rsync(1) using the SSH protocol with pre-shared keys. Pulling content from a central infrastructure onto the device is OPTIONAL and not intended nor to be implemented in the current design.

Content

Format

Content to be pushed onto devices SHALL be packaged and compressed in ZIP format [1]. The implementation MUST support multiple ZIP files to be pushed onto devices concurrently.

ZIP File Directory Structure

A ZIP file SHALL contain one (1) or more subdirectories in accending number sequence (e.g. 01..99). Each subdirectory contains the contents of one (1) website to be displayed. An example tree structure might look like this:

contentupdate-2014-08-19.zip:
  /01
     index.html
     graphics/
              ad.jpeg
              header.jpeg
              [...]
     time
  /02
    index.html
    gif/
        ani01.gif
        ani02.gif
        [...]
    time
  [...]

Display Time

Each subdirectory contained in a ZIP file MUST contain a file time. This file will be used to define display time periods (i.e. how long a certain website will be displayed until rotation continues).

The time files only content is a duration specified in milliseconds.

An example may look like this:

  08/time:
    150000

(The only content of the file time in the subdirectory 08 is 150000. Which specifies two and a half minutes of display time)

Updating and removing active content

Newly uploaded ZIP files MAY contain an updated or empty replacement of a previous actively displayed directory. This can be used to change active content as well as to remove active content. An empty directory MAY be placed inside a new ZIP file with the same name as the active directory to be removed. The empty directory MUST be ignored by the software implementation.

[0] - W3C: WebDriver
[1] - Selenium2 - WebDriver
[2] - .ZIP File Format Specification