I was brainstorming retarded, ridiculous, and unheard of general hardware ideas and thought I might share this one with you all and see what you guys think

I need a hardware project otherwise I'm going to go insane with all this web development

So how hard would it be to make an LED marquee and connect it to an 84P to allow the user to input any message and have it display on the LED marquee?

Lets start simple now, of course. Here are a few methods I thought of to make this possible.

Option 1
Build a 12 x 112 LED Marquee, and simply have it display what ever is on the calculator's screen. Basically same concept as a dual monitor system. So, in theory, this would display this first two lines on an 84p's home screen.

Option 2
Build an LED Marquee, and have the calculator "upload" a message on to the Marquee that would then display the message constantly unless switched off. The benefit of this would be that you didn't have to have the calculator set up. The bad thing is, I assume, it would require a little more advanced architechture involving microcontrollers and other small chips (but I suppose the first idea would as well... unless the ASM program sending the information to the LED Marquee was written to handle the Marquee completely on its own, instead of sending it raw data for the Marquee to interpret itself.)



I apologize if any part of this post is confusing or not easily understood. I'm partially asleep right now, so forgive me hehe




While browsing a bit I found this...
http://www.electronickits.com/kit/complete/ligh/CKH001_Scrolling_Sign_Kit.htm
Might be of use in this situation, might not...

and this...
http://www.instructables.com/id/LED-Dot-Matrix-Display/


http://www.futurlec.com/LEDMatrix.shtml

Strangely enough, I built a 120x5 display for my Digital Logic Design purely out of discrete logic. It has a hand-built ginormous 1-to-120 multiplexer for the columns, a 1-to-5 multiplexer for the rows, about 2KB of 2114-series RAM chips to store data, bus arbitration bidirectional hex buffers, and of course a log2(120*5)-bit counter to refresh the display. I built a parallel-port program to program it, but I never got that fully-working; this might be something fun to use it for, connect it to the calc. I'd need to make sure it still works, then add an 8-bit shift register to the programming interface, and add some rudimentary logic to it. Maybe hold both lines low for x ms to clear and reset, then one line is data, the other line pulses to the next pixel.

Hey cool

If it all works, you definitely need to write some type of how-to

If the meantime, do you mind possibly giving me a jump-start by typing out a list of items I may or may not need for this to be accomplished?

I suppose a variation of the Instructables LED display might be the trick, but I'd have no clue how to make it control a large array of LED matrices.




And is it just me or can Futurlec not make up its mind on which type of matrix should be the more expensive one?
5 x 7s, the square version is more expensive
8 x 8s, the square version is much less expensive.
wtf mate?

Don't order from Futurlec; they're mad slow at shipping and have a history of getting people's orders wrong (namely mine )

Have any other suggestions?

[EDIT]
Here's an interesting Tut/How-To/thingy I found
http://www.maxim-ic.com/appnotes.cfm/an_pk/1033