VSSDCP

Experimental communication protocol used by serdisplib to control display modules

Introduction

Communication libraries

• VSSDCP_base is an abstract class and cannot be used directly but is required for all derived classes.

• VSSDCP_serial implements serial communication (via serial port or USB).

• VSSDCP_ethernet implements communication to an 'Ethernet Shield' via ethernet.

• VSSDCP_uipethernet implements communicaiton to an ENC28J60-based ethernet board.

To be able to get a working VSSDCP implementation on a Teensy or Arduino-board, at least VSSDCP_base must be installed and one of the other VSSDCP_* libraries.

Required libraries (PC / Linux):

• serdisplib

  Branch of serdisplib with very experimental support for VSSDCP (author: Wolfgang Astleitner)

Required additional libraries on a Teensy or Arduino-board:

• SmartMatrix

  either original version: max. 32x32 pixels (author: Louis Beaudoin)

  or my fork with multi-panel support

• display library

  library that supports your display module

Getting these libraries:

• serdisplib

  svn checkout https://svn.code.sf.net/p/serdisplib/code/serdisplib/branches/vssdcp serdisplib.vssdcp

• SmartMatrix (original version)

  git clone https://github.com/pixelmatix/SmartMatrix SmartMatrix

• SmartMatrix (my fork with multi-panel support)

  git clone https://github.com/mrwastl/SmartMatrix SmartMatrix

Important

Only VSSDCP_serial is working in a usable way, VSSDCP_ethernet and VSSDCP_uipethernet are very error-prone and unreliable (either because of errors in the VSSDCP-implementation of serdisplib or because of the VSSDCP_* libraries). Improvements and/or ideas for better implementation of communication are very appreciated.

Installation

The folder 'VSSDCP' contains several libraries. At least library VSSDCP_base has to be installed and one of the other VSSDCP_* libraries.

Usage

One of the VSSDCP_* classes (VSSDCP_serial, VSSDCP_ethernet, VSSDCP_uipethernet) needs to initialise a class that passes the commands to the display library.

e.g.:

class VSSDCP_somedisplay : public VSSDCP_serial {
         VSSDCP_somedisplay (void) { }
  void   setup              (void) { /* setup display module, setup VSSDCP */ }
}

VSSDCP_base contains some examples.

Testing

Testing the correct communication with serdisplib (serial communication, Teensy only (baud-rate is not required)):

src/testserdisp -n vssdcp

src/testserdisp -n vssdcp -o "brightness=30;acknowledge=0"

If an arduino-based board is used, you have to set an appropriate baud-rate (both in your arduino-sketch and in serdisplib):

src/testserdisp -n vssdcp -o "brightness=30;baud=9600"

mplayer

I've programmed a batch for mplayer to support my library:

https://github.com/mrwastl/mplayer-vo_serdisp

The README.md contains the instructions for patching mplayer-soruce and compilation.

Command line example:

LD_LIBRARY_PATH=/path_to_serdisplib_with_vssdcp_support/lib ./mplayer -vo "serdisp:name=vssdcp:viewmode=1:options=brightness=30;acktype=0" -framedrop -ao null somevideo.mp4