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Library for easy alpha-numeric display on an LED matrix? Answered

I'm looking for a library for either the Arduino or AVR line of microcontrollers, that enables easy display of scrolling text on a 5x7 or 8x8 LED matrix.  Here's what my requirements are:

- The library should contain a table of common alphanumeric characters (alphabet, numbers, and maybe some symbols)
- A function should call up any number of letters to form words or phrases, like this:


- Once the function is called, the text automatically scrolls across the display
- The function can be called from anywhere, like if/then statements, case statements, results of random numbers, etc.
- Additional modifiers, like scrolling left or right, speed, and repetition would be nice to have but not necessary.

I've searched the AVRfreaks forum and various Arduino forums, but haven't found what I'm looking for.  So far anything I've found is basically hard-coded bit-banging, making it difficult to change the text and impossible to store more than maybe 100 total characters.  My goal, with a set library of characters, is to have the ability to play back hundreds or thousands of characters, arranged as single words or phrases.  They should be as easy to change as typing in a new sentence in plain language into the code.
So, has anyone come across such a thing?



7 years ago

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8 years ago

Hey Jeff-o!

Sorry this is a little late.  Here (or maybe I'll email it to you if I can't get the formatting in this post) is code for what you are wanting (I think).  It takes a message is a char [ ] and scrolls it across a DLO dot matrix led.

-- The formatting won't work for me so check out this URL --
Code for single letter and delayed scroll

If you need more help or want to add functionality to it, you have my email :)



Answer 8 years ago

Wow, that code sure is short when the DLO LED matrix does all the heavy lifting!  I actually did find something myself in the meantime, that should do what I want using a non-intelligent dot matrix display.  But for future versions of the projects I'm working on, this DLO might be just the thing!



Answer 8 years ago

haha yah for a couple of bucks, the DLO is worth the money for a smart dotmatrix LED, because, like you said, it does all the heavy lifting. :)


8 years ago

I had trouble recently displaying numbers with a PIC and alphanumeric LCD display. I could not do it properly, so instead I wrote a function which looks at the number called as a parameter of the function, and then output it as the text equivalent.

I suspect you could build something similar for these matrix displays, and use a three dimensional (I think) lookup table for each row of each character, and print each row of the character in sequence.

You might need external support electronics setup something like this.