between the SD (Secure Digital) memory card and the PC via white-LED light. The entire
system consists of a pair of identical white-LED transceivers: one is connected to the PC,
whereas the other is connected to the SD-card subcircuit. File transfer operation is able to
execute at 19200 bps. Prototype 1 is based on pulse-position modulation (PPM), while
Prototype 2 is based on pulse-width modulation (PWM). It was found that the PPM design …