Very Low-Cost Sensing and Communication Using Bidirectional LEDs

Very Low-Cost Sensing and Communication Using Bidirectional LEDs
Citation:	Dietz, P.H.; Yerazunis, W.S.; Leigh, D.L., "Very Low Cost Sensing and Communication Using Bidirectional LEDS", International Conference on Ubiquitous Computing (UbiComp), October 2003 (UbiComp 2003)
Date:	July 2003
MERL Contacts:	Paul Dietz, Darren Leigh, William Yerazunis
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. video: http://mrl.nyu.edu/~jhan/ledtouch/ledtouch.mpg