RGB Matrix Alphabet

Hello everyone, I was looking for advice on how to write an alphabet for the Sprakfun RGB Matrix (with backpack). I was thinking about writing subroutines (or whatever you want to calla section of code with void in the header) for each letter and assiging the corresponding LED number to the color buffer. I figure that there has to be an easier way to do this with arrays, I'm jut not sure how. If anybody has any tips, I would love to hear them. EDIT: Also, I was wondering how to get the text to scroll, it seems uneccessary to have to adjust each value.

If you're able to add an EEPROM (http://www.sparkfun.com/commerce/product_info.php?products_id=525 ) then I would suggest using it to store your font. You'd make a sketch to load the character set into the EEPROM one time. Then it is always there for what ever you want to do with other sketches.

Generally, characters are stored in an array with say 8-10 bytes for each letter. Each bit = an led. The index of the array determines the letter.

As for scrolling (marquee), you should be able to find examples of this. They often use a buffer and characters are pulled into it column by column. Then the buffer is displayed. Then it is shifted to the left, and cycle repeats.

At least this is the technique I use. ( i.e. http://www.youtube.com/watch?v=YL1keLtU9Tk)

Alright, thanks for the help. Just ordered an EEPROM chip off of Sparkfun and will try it out as soon as I get it. Also, that's a great design you used. It's kind of lick mr. nick's design only slimmer and made using only one matrix. I was planning on making something like that, scrolling date, time, waether, etc. and will definately be using your video as a reference.

Thanks, and since it appears your going that way, here's just a few things from my experience you might want to consider moving forward:

  • If you use 10 bytes / char (even though you may need less - you have [u]lots[/u] of room) and you start loading at address 320, then to address say "A" it is the ASCII value of "A" x 10.

  • You can store strings in the eeprom as well as the font.

In any case, good luck! :)

Thanks, hopefully I will receive the chip tomorrow. Will definately be posting questions on this site if when I have them.

You can store an ASCII font in the Arduino's EEPROM. PM me for some code as it's too long to post here.

Okay, after receiving the wrong package from Sparkfun and going through a lot of waiting, I FINALLY got my eeprom chip today. I have it all setup and attached to the Arduino, and I have already written the basic functions to read, write, etc (found them in the playground). Now, I have absolutely no idea where to start. I'm still really new to this level of Arduino code (only done things using basic LED's and sensors) so I'm kinda stuck. Thanks in advance to anybody who helps (and to those who have already helped :) )