Mar 30, 2009
Out flying with kids (model airplanes) buzzing them with the plane. they thought it was fun to try and hit the plane with sticks and whatnot. but obviously that's not good so they started thinking about having some kind of laser gun to shoot the plane with. thought about it, figured out it can be done with a laser pointer and a detector on the plane. The idea is real life Star Wars fun. The plane flying above will shoot people on the ground, and the people on the ground can fire at the plane. When hit, the people or the plane go 'down' and are out until there is only one person or plane left standing or flying. This game was invented by a few 8 year olds and we were determined to make it a reality!
Detecting a laser beam means distinguishing it from all other lights in environment. Decided to use a technique where we modulated the light from the laser pointer in a way that it could be distinguished from other light sources. the technique is called quadrature aperture sampling. this sensing technique is called quadrature aperture sampling. implies that you use a micro controller to measure the intensity of a light sensor at carefully selected intervals, meaning that we're measuring the light's frequency. imagine that we're blinking the laser really quickly if we sample the light sensor a number of times when the light is on and a number of times when the light is off and subtract those two, then we measure the difference in light intensity at a specific frequency whereas un-modulated ambient light is filtered out.
More Photos Here: http://www.flickr.com/photos/29889578@N05/3398307846/in/photostream/
Movie here: http://blip.tv/file/1935803/