Portable rear projection stereoscopic display

Hardware Details

 Contents -- Theory -- Hardware -- PovRay -- OpenGL -- DVD -- Details

Cabling overview

DVD controller logic

The serial splitter has two functions, the first is to echo any serial commands on the input serial line (from the computer) to each output serial port (to the DVD players). The second is to create a contact closure on each DVD player, this is how the DVD players are started exactly in sync, a mode supported especially by the model of DVD player used.

The serial splitter simply accumulates any characters sent to it except for the hex bytes 0xFF, 0xFE, and 0xFD. These three command bytes act as follows:

0xFF    Send the contents of the current buffer to both output serial ports.
0xFE    Flush (empty) the current buffer.
0xFD    Toggle the relay.

The exact commands to drive the DVD players can be found in the DVD player manual, they are all printable character strings. A subset of the commands are given below.

RJ    Stop
FR%dSE    Go to a particular frame in the current title.
TI%dSE    Go to a particular title number.

Note
  • All commands terminate in a carriage return ('\r').

  • The serial communication settings are 4800 baud, 8 bits, 1 stop bit and no parity.

  • The contact closure is required to start the DVD players, the "play" command as a serial command is not sufficient to start the two players together.

  • The DVD players return a status after each serial command to indicate success or otherwise. This system ignores that status.

Software solutions

There are a number of commercial and freeware software solutions that support stereographics. Unfortunately standards for stereoscopic images and how they are projected are mostly out-of-date. The two most prevalent forms of computer based stereo are frame sequential and side-by-side display, the later is used in this project. Software developers are encouraged to support both and the OpenGL sample code provided here does just that. There are a wide range of software solutions written by the author to met specific needs, a subset are listed below. For more information please contact the author.

  • stereo2 - general display software for static geometry described in the GEOM format.

  • playmovie - plays stereoscopic movies, includes tools to build stereoscopic movie files.

  • glslides - displays slide shows of stereo pairs.

  • glgraph - 3D graphing of data of 2 variables.

  • pointanim - animates a time varying collection of points with attributes.

  • surfanim - animates a 2D surface with scalar or colour mappings.

  • panoramic - displays stereoscopic panoramic images.