Introduction: An LED You Can Blow Out Like a Candle! About: Currently, I'm at a startup trying to change the world. In previous lives, I was an EE Prof., an Imagineer at Disney, and, according to Jay Leno, "a Japanese scientist" (I'm not Japanese, or a scientist). In a… More About electron_plumber » LEDs are designed to emit light, but they also make surprisingly capable sensors. Using only an Ard