cmjDEV

Creating the MatrixLED Library

When I started writing the MatrixLED library I had ZERO preconceived notions about how it should be implemented. I just started coding some stuff to get it to do some other stuff. I ended up creating a 128 byte buffer that allowed me to store and manipulate 16 ‘frames’ (8 bytes per frame * 16 frames = 128 bytes).

This worked and was very easy to implement but it was rather bloated. I would take in an ASCII string, look up the equivalent ‘frame’ for each character and write those 8 bytes to the buffer. The actual screen was mapped to the first 8 bytes of the buffer. This means I needed to keep track of how big the buffer had grown and resize my manipulations accordingly. I started thinking about how I could do this in place and realized it was possible without an external buffer. I rewrote the code and have made some decent progress.

As of right now there is an 8 byte screen buffer that is mapped directly to the matrix. There is no shifting of data into the ‘screen’ area. This frees up space and cpu cycles. I’m not convinced that I will be able to implement all of the features I want without some type of scratchpad, but at least I can add one later if I need to.

I’m going to spend some time tomorrow polishing up the marquee function, and start working on some user input.. My goal is to be able to move a pixel around the screen by the end of tomorrow.

Videos will follow.

Here is a link to the new code
Compare with the old method 

Be aware, the second link has not been tidied up.. It works completely tho so that is why it remains the master branch.