Phototransistor-like Light Controllable IoT Sensor based on Series-connected RGB LEDs

TL;DR

This paper introduces a novel IoT optical sensor using series-connected RGB LEDs that functions like a phototransistor, with programmable responsivity and dual roles in communication, simplifying system design.

Contribution

It presents a new light-controllable IoT sensor based on RGB LEDs with a theoretical model explaining its unique optoelectronic response.

Findings

Maximal responsivity to violet light

Programmable blue light responsivity

Dual transmitter-receiver functionality

Abstract

An IoT optical sensor based on the series-connected RGB LEDs is designed, which exhibits the light-controllable optical-to-electrical response like a phototransistor. The IoT sensor has the maximal AC and DC responsivities to the violet light mixed by blue and red light. Its responsivity to the blue light is programmable by the impinging red or green light. A theoretical model based on the light-dependent impedance is developed to interpret its novel optoelectronic response. Such IoT sensor can simultaneously serve as the transmitter and the receiver in the IoT optical communication network, thus significantly reduces the system complexity.