TRIKLITS

SD Card File Format

The Effects Controller can read pre-programmed effects from SD cards. This page gives you information on the file format in case you are a developer and want to write software to create your own effects files.

The SD card must be formatted for FAT or FAT32 format, and only 8.3 style file names may be used. Each file must be written contiguously to the SD card, and for that reason, you must start with a freshly formatted card before writing files to it.

Every file on the SD card contains a 512 byte header, followed by RGB data.

HEADER

File header, first 512 bytes.  Many bytes are not currently used and should be set to zero.  The remaining bytes are:

INDEX     NAME         DESCRIPTION
 0-1       signature    always 0xCC 0x33    
   3       address      if 0 defines EC as master, should be 1..N for slaves
  11       format       file format, currently must = 3
                       
  16       delayf       fraction of a millisecond
  17       delayi       integer number of milliseconds

    These bytes define the output frame rate.
    For example, for 30 frames per second the time between frames would be 33.333 milliseconds.
    So delayi=33, delayf=84    (256*.333 = 84)

DATA

The rest of the file consists of 24-bit RGB data as repeating R,G and B byte values. The length of a frame is determined by the settings in the Effects Controller (based on total number of lights configured). For example, if configured for 8 strings of 25 lights, then a frame is 200 lights or 600 bytes of RGB data.