An LED-to-LED Visible Light Communication system with software-based synchronization

An LED can emit and receive light and provides therefore a simple building block for a Visible Light Communication (VLC) system. We describe a microcontroller-based system and report on its effectiveness in a testbed. The key idea is to use a microcontroller to provide synchronization so that the receiver can lock to the transmitted signal in a fast and efficient way. Further we propose a combined light emission and light measurement approach to receive with an LED while emitting light. The proposed system enables new entertaining applications by creating the illusion (for a human observer) that both transmitting and receiving LEDs are always switched on.