LED Wall Map Project

I am designing an LED wall map which will light up various cities around the world in real-time based on live search traffic from Kayak.com (where I work). The wall map will be about 3-4 feet tall and 5-8 feet wide, and have about 100 LEDs. I'm doing this project just for fun; I will probably make two or three of these maps (maybe different sizes) but I will document the whole project here (including exact parts list, where to buy each item, how much money each item costs, and all source code which will be GPL) in case anyone else wants to do a similar project. (If so, please let me know about your project.) I will also create a software-only version which will "light up" cities on a web page.

The hardware design is being done by Adam Kaczmarek and Ken Schrock.

Here is a preliminary schematic, and the pcb.

Hardware Components

• World map wall poster. Froogle
• 100 LEDs, possibly tri-color. eled digikey YDI ledsupply optoloco
• Controller for the LEDs, should be able to handle over 1 million events per day, each event being some combination of 100 LED commands. IO-Warrior pdf
• Power supply for the LEDs and controller.
• Linux server, inexpensive rack mount, with custom software for controlling the LED map.
• Mounting board to hold the LEDs behind the world map. Possibly foam core? Froogle
• Poster frame (and glass?) Froogle

Issues and Questions

• How should we connect the LED controller to the linux server? Serial port? Parallel port? IR? USB? Ethernet??? Each of these have different implications for cost and complexity of the map vs. the computer. Ideally the computer could be up to 30 feet away from the map, and the system could be designed to work with either a linux server or a Windows pc.
• How will the software change LED state? Will it continue to pulse requests for the full set of LEDs which should be on (thus not requiring "memory" in the map controller) or will it instead only send commands when an LED is to turn on? How long will each "turn on" command last? Should we use capacitors to make this longer, and if so, what type, and how long will they allow an LED to stay on?
• Should we also put one or two input devices on the map? To allow viewers to adjust the display, e.g., flight origins vs. destinations, air vs. hotel search, etc. If so, what type of input devices?

References

• Public Displays, Joseph F. McCarthy, Intel Research