I wanted to make our class stick out more than the others at the pep rallys, so I decided to build an LED banner/sign that would display class of 2013.
AA batteries and holder
first print out the letters for your banner using regular paper and cut them out. Lay out the letters on the foam core and using your soldering iron, punch a hole through the paper into the foam core every quarter inch after each hole because the LED's are about 1 inch long and each one has to be connected together. Then insert each LED in each hole in the foam core and throw away the paper.
Next each negative lead on all the LED's need to all be connected together in parrallel, then a 510 ohm resistor needs to be connected to the positive of each of the LED's. Then all the other ends of all the resistors need to be connected in parallel, this will be our positive lead that will go to our switch
Now we need to connect all the positive and negative terminals from all the letters together and hook the positive from all the letters to one side of the switch. The negative terminal coming from all the letters needs to be connected to the negative terminal on the battery pack (8 AA batteries) and the other pole on the switch needs to be connected to the positive terminal on the battery pack.
Last of all we need to build a small wooden rectangular frame to velcro the front and back foam core to. I cut a small door on the back where to switch and batteries are to make it easy to turn on. I did this project in a rush so I used duck tape to hold the switch and batteries in place. The reason why the "of" is darker is because i ran out of bright LED's and had to use the ones I got that were too dark. I also added a handle to the top of the sign.
And your good to go.
Also check out my SkillsUSA banner with over 200 LED's and a microcontroller