V4.0 - LED Matrix Circuits

As my photos illustrate all too well, the wiring of the matrices is pretty hairy. I'm planning to have some more prototype boards made as a back for each matrix. I'll try to build in the interfacing between these boards, so they'll all plug into each-other when I build a larger array.

I'm still using the freeware EagleCAD program, and I'm right in the middle of building a new library for the matrix. There's already a part for the MAX7221 (actually the MAX7219) so I don't have to worry about that.

I'd like to get the boards ordered ASAP, so I can experiment with more matrices at once. Though, I'm concerned that I'll discover the boards are wrong or could have been better. Kind of a catch22, so I may just have a couple made up or do them at home again. (sigh)

V4.0 - LED Matrix Code Driven Animation

I'm pretty happy with myself for this one. I've been reading the recently published book on Processing. I'm glad too, because the Arduino environment is based on the Processing language and this has given me enough understanding to patch together the useful pieces of code I found earlier.

There was an early example in the Processing book of a bouncing ball within a little rectangle on screen. I thought I might be able to adapt that code to work in the matrix. It didn't need much adjusting, and was much simpler as I didn't need to "draw" a rectangle or an ellipse. So, check out the bouncing:














Arduino Code:
Bouncing Ball

V4.0 - LED Matrix Animates

I created a couple monotonous pieces of code to generate an animated line. Before I did any serious coding I figured I should just try shoving a bunch of frames at the matrix and test the speed/refresh rate. I did make an Excel spreadsheet, where I can fill out grids that generate their own code.











I made a couple animated sequences with that. Click on these frames to see the animations:









































Arduino Code:
Counting Animation
Pattern Animation

V4.0 - LED Matrix lights up

I found a great deal of help with this online. Oddly specific to the task, a search for MAX7221 and Arduino gets a lot of results in Arduino forums and project pages. There's a little code, but mostly overview, basic questions answered, details meaningless to beginners (like me), and my favorite pseudocode.

I did get this to work anyway. I'll be adding screen shots, code examples, and process later. Here's some visual documentation:

V4.0 - LED Matrix work

As I'd sort of expected, I have decided that V4 will be higher-res. I hope it to be way higher-res, but we'll see. The plan for now is to use an Arduino board (that has been burning a hole in my project table) for the control. It has a pretty fast chip, 10MHz, so I'm hoping it'll be able to keep up with all my spinning about.

I got all the pieces in the mail that I'd need, had the Arduino, a couple LED matrices, and a couple matrix controller chips from Maxim-IC (MAX7221). Putting this all together is a heck of a lot harder than re-arranging the parts on the SpokePOV, but here goes.