Interactive Lighting Installation

Hey, for a new art gallery we’re opening in our town, the building we got used to be a pawn shop and has bars in the front windows. Rather than removing them, we thought it would be cool to use them to mount a custom lighting installation… columns of LEDs would be mounted on the front of each bar, such that the distance between LED’s is about the same as the distance between bars. One or more sensors would be set up to track pedestrians as they walk by our window, and the LED’s will light up in a pattern that follows the person as they walk by. Later we’d like to upgrade the system by having the bars function as a graphic equalizer, scroll some text, play pong, etc, but for now even if it’s a dumb system that does nothing but translate distance to number of LED’s lit, that’s cool with us.

I’m stuck on deciding what sensors I need, and if it’s going to be possible to control everything from one arduino. There’s 13 bars in the window section I’d like to use, so we’re looking at individually addressing 169 LED’s, and then I’d like to know what the cheapest way to get it to track pedestrians across the window is.

Any help you could provide would be appreciated. Thanks!

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This type is longer range, 20 ft., it senses a wide area though: http://www.adafruit.com/index.php?main_page=product_info&cPath=35&products_id=189 You could put it inside a narrow tube or slot so that it would cover a narrow area.

This is a distance sensor that is more specific, measures straight ahead, but has only a 1 meter distance range. http://www.adafruit.com/index.php?main_page=product_info&cPath=35&products_id=164

The sensors are about $10 each, so it might be cost prohibitive to use a lot of them. If so, you could put one on each side and just guestimate the average walking speed. Or, you could have two on each side and calculate the walking speeds based on the time between them.