Demonstration abstract: Enabling WSN nodes to send data to smartmobiles by blinking LEDs

Greendicator is an indicator system that enables embedded systems to output text to camera-equipped smart-phones by blinking an LED. The transmitter emits modulated light pulses using an existing visible-light LED or an IR diode, laser, or light reflector. The receiver uses a camera-equipped smartphone to sense the light pulses and GPU to decode the original message. We demonstrate its use in supporting existing RF-based networks and an aid for pairing and configuration of wireless systems while occupying only a small memory footprint.