Ok, so yes, its yet another CGOL. I built this 10x8 matrix of 1" 7-segment displays ages ago. I used to drive it with a PC parallel port and perl code, but decided to revive it and drive with Arduino.
Each display has a 74HC595 shift register on the back, soldered directly to the display using 1/8w 300R as jumpers. Its all one long shift register, whole thing is driven by only three pins. Its nice, simple because there is no scanning, but is SUCKS juice.
Future improvements:
Currently i am only using the a, g and d segments for the GOL display, need to put some thought into how to map more segments.
Make a bigger one!
Need to make (or steal) a better CGOL implementation, Using a whole byte to hold a cell value of 1 or 0 is silly. I can do better.
See links in comment below.... first post on this forum, so couldnt embed links directly...
Heh, Yea that took a number of hours. I want to make a PCB backpack board for 7-segment displays. Either using the shift reg like shown or one of those TI constant current sink driver chips that drives 8 displays. I havn't found anything like that already done...
Good links thanks. I've seen some of those, but what i am really thinking of is a board that i can build large matrix of 7-segment displays. I need to brush up my CAD and just build it
Actually, I did just add 2 matrix drivers to my Lightuino V3.0, so it will do a matrix of 1120 LEDs (16x70 or 32x35 for example). Just got prototypes in actually so I haven't posted anything about it.
But I think that sysmatt was suggesting something different -- and that is a board that goes behind the matrices so you don't have to solder them all together. I've thought of that a lot and may actually do one. But there are 2 problems:
Its a lot of PCB space for few wires so you are paying a lot for it.
Each matrix type would require a different PCB so you'd have to pick one. There are SO many different sizes, types, and pinouts. I'm not sure if enough people would be willing to settle on a particular size.
Yes i was suggesting backer boards for the 7-segment and 14-segment displays. I agree the problem is the huge range of pinouts and sizes.. I dont even know where to begin trying to pick..
I just finished doing up another CGoL project using a 3x3 matrix of 5x7 dot displays, Used 74HC595's on the x and y, sunk to transistors. I re-wrote the CGoL code to pack stuff in memory bitwise, rather than wasting a whole INT on boolean. Also my first Arduino project to use timer/interrupt. The matrix refresh is all interrupt driven, works very nice!
I will put a separate post on that when ive cleaned up the code a bit more.
Did you just buy a bunch of used 5x7s mounted on circuitboards of 5 matrices on ebay? I know that it was me and one other guy who were buying them up! They were about $1.50 per board so it was a real deal (these are big matrices 3x5 inches or so).
I'll post more details on the Lightuino 3.0 when I have it ready. But its probably very similar to what you have done; the MM5451 chip that I used is very similar to the 595 shift registers, except that it has 35 constant current outputs (so not resistors!) but does not allow one chip to be daisy chained to the next.
So far I've just text scrolling...if you need code for text display you are welcome to it!
If anyone is interested, I have photos of how I assemble the 7-segment modules and shift registers. It looks like its very complicated, and I guess it is somewhat. It goes quick, and you cant argue with results (as my electronics teacher used to say quite often)
I've used this design on a number of projects. Soldering, Wire-wrap, wire-art... Its a multi-discipline project.
Like i said, This type of thing would make a really nice circuit board one could make a display of any length simply by trimming the board.
And best of all, Since the shift-registers are like static ram, there is no scanning!
