Annotation. This article presents an approach to optical communication using visible light using a focusable LED flashlight as a transmitter and a digital camera as a receiver. One of the innovations of the approach is that the design can integrate standard light source and camera components and is designed to work indoors under typical lighting conditions, i.e. overhead lighting and ambient daylight. The communication signal is transmitted as a sequence of values (1,0) that turn the light source on/off. The camera receives the signal by observing the presence/absence of a projected light spot on the intermediate surface and converting it back to a binary signal (1,0). The approach applies image processing techniques to calculate the received signal from the recorded image from the camera.

Keywords: Li-Fi, Visible Light Communication (VLC), image, recognition, LED, flashlight, Raspberry Pi, digital camera.