I suspect the world would be better if that percentage were even greater.
MERL – TR2003-035 – Very Low-Cost Sensing and Communication Using Bidirectional LEDs
A novel microprocessor interface circuit is described which can alternately emit and detect light using only an LED, two digital I/O pins and a single current limiting resistor. This technique is first applied to create a smart illumination system that uses a single LED as both light source and sensor. We then present several devices that use an LED as a generic wireless serial data port. An important implication of this work is that every LED connected to a microprocessor can be thought of as a wireless two-way communication port. We present this technology as a solution to the “last centimeter problem'', because it permits disparate devices to communicate with each other simply and cheaply with minimal design modification.
MERL – TR2003-035 – Very Low-Cost Sensing and Communication Using Bidirectional LEDs.
Comment from Sol
Time 11/13/2008 at 10:22 pm
Thank you. The “full technical report” pdf (http://www.merl.com/reports/docs/TR2003-35.pdf) in the link referenced is full of useful instructions and technical details.