SD card data format - Advise needed

Hi Folks !

I want to create an LED panel, that is going to be 32 x 12 LEDs. I'm planning on using WS2812B LEDs.

I want to be able to program sequence of animation, but saving all these in the Arduino itself, would be consuming memory like crazy, so a friend of mine, who is a "Nerdo" for creating program, offered to create a custom application, that would visually allow me to create a series of what we called "frame": basically, an "image" of what the 32x12 LEDs should look like (which one are ON, what color are they, etc ..). In the Arduino, I would need to read a frame, display it, read the next frame, display it, and so on ...

This friend of mine, knows nothing about Arduino though....

He says he can save the resulting words in a format that would look like the attach file. In resume, each pixel, would be a 32 bits word:

  • bits 0-7 => Bytes value for Red component
  • bits 8-15 => Bytes value for Green component
  • bits 16-23 => Bytes value for Blue component
  • bits 24-1 => Miscellaneous info, such as is this the beginning of a new Sequence, a new frame ...

My questions are:

  • is it possible, in the Arduino, to read that 32 bits word, and segregate as 4 bytes ?
  • Would I be able, to read a particular word, within that file, let's say read word 345 ?

If anyone has done something similar or has ideas/hints, please let me know !

Each frame will require 32 x 12 LEDs x 3 bytes/LED = 1152 bytes.
I'd suggest a processor with more SRAM than the 2048 bytes in a '328P.
I offer '1284P boards with 16K SRAM for holding several frames at a time.
This one is Uno-like for example
http://www.crossroadsfencing.com/BobuinoRev17/

ok, but would I be able to read, let's say 2-3 frames, proceed one frame, then load another one, proceed, and so on ??

I'm not that familiar with reading from an SD card. Do I have to read the whole file at once or I can read 'x' number of word, stop, then keep going ?

When I read, am I going to read 4 consecutive bytes, being part of the word ? if so, what am I reading first ? MSB or LSB ?