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[on:]

Hello all, well I am graduating in May and would like to make a simple but yet effective LED graduation cap. I have already ordered a 32x16 bi color display from Sure Electronics. I initially intended on making my own matrix, but with time constraints and school I figured this would be an easier approach. I have a moderate grasp on electronics but not so much the micro aspect of it.

I know there are a lot of similar projects (just not mounted on a cap) to be found on the internet, but I have not seen anyone who has used an Uno for scrolling text (maybe some clocks), most use the Mega 2560. Is this a must for the 3216 display or can the Uno be used? Any advantages of using the Mega2560 vs. the Uno if applicable? Is the # of outputs on the Uno the limiting factor?

The Mega256 is obviously more expensive and everyone seems to be out of stock of them anyways, so If I can save some $ and Use an Uno to do the same thing would be amazing. Any knowledgable input would be greatly appreciated. This is my first micro-controller project so please excuse my ignorance. I am a chemistry major not a electrical engineer . Thanks!

[Reply #1 on:]

Any input on this one?

[Reply #2 on:]

Dude.

The display alone weighs 8 ounces. Batteries and electronics? At least another 8. That's a pound right there.

And you're going to put that on your cap?

Even if that all worked perfectly and weighed nothing... You'd still be turning your graduation into a circus.

Why?

Dude. Just graduate like a normal person and throw your cap in the air.

[Reply #3 on:]

Id go with a teensy++ (or even a Teensy) instead of either one of  those.
http://www.pjrc.com/teensy/
The Teensy++ is cheaper than many places sell the Uno board and has lots more resources than the Uno.
(even the Teensy has more resources than the Uno)
The Teensy++  has 128k of flash (half the 2560) but I don't think code space will be an issue for this project.
It has the same RAM as the 2560 and 46 instead of 54 i/o lines (should be more than enough).
To me the big advantages are lower cost and smaller size.
Teensy boards are tiny and much lighter than either the Uno or Mega board.

To really save weight and some cash, you could even build your own led matrix
to scroll some text. See this project:
http://www.nerdkits.com/videos/ledarray2/
You could keep it small and use some very light weight foam board to hold the leds.
If you paired this with a teensy++ (even the smaller teensy would work) it could
be fairly small and very lightweight.


--- bill