Hi all!
I'm new to arduino and I have a couple questions. I'm interested in making a programmable LED display; somewhat like announcement screens outside of schools and such. I essentially want to make an electronic message board using arduinos and LEDs. My questions are:
-Is this a realistic enough project to take on?
-If so, what kind of arduino would be best suited for the project?
Thank you so much for your help!
Please specify the size.
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html
If you go to youtube and search for arduino scrolling text
Or even google you will find many types of scrolling text using various display types.
Tom... 
If it's the type of displays that we have at our middle school that costs thousands of dollars I am thinking I haven't seen displays that large that can be controlled by an Arduino.
@aarg: I was thinking about 96x48cm would be ideal!
@TomGeorge: Thank you, the search did help!
@ieee488: thank you, you make a good point. Screens of that size would be unrealistic.
If you using 3mm 8x8 LED Matrix it will be 96/3.2 x 48/3.2 = 30x15 = 450 Pcs of LED Matrix used.
That will be 240 x 120 Pixel
Arduino should be able to control it.
More important than outline size: how many LEDs do you plan to have? The 240x120 pixel resolution as suggested in #5 is not much, but could be enough depending on what you want (at 8x6 per letter that'd be about 12 lines of 30 characters each if you stick to basic ASCII but not really useful for images).
You can also look at multicolour LEDs for a more colourful display.
There are plenty of such LED cubes around that are Arduino controlled, and can do pretty dazzling things with colours. Look at such devices as well for developing your board, as many components are similar.
@billhowl: Thank you very much, that sounds great! It was very helpful to get a number for how many i may need!
@wvmarle: I hadn't thought about an exact number yet, but you brought up an interesting point. I had never consider images in the display, but it sounds intriguing! What size would you recommend for images? Thank you!
Sorry, can't recommend numbers, just letting my thoughts go over other people's projects. For images of course the bigger the better, and the more colours (such as multi-colour LEDs) the better.
I think you should start by looking in how to drive those LEDs, how many outputs you can get from your Arduino (you'll need port expanders), and how much work a single Arduino can handle. That will quickly enough tell you the absolute numbers. Go from there.
Use MAX7219 based 8x8 modules & Parola,h library.
8x8 matrices can be had with different size LEDs, pay attention - 3mm, 5mm, 8mm, maybe 10mm.
Or a larger board can be designed to hold LEDs that are spaced out more, larger for viewing from farther distance.