LASER Communication and GSM based Text Alert System

2018

It was an interesting project where I used LASER as a carrier to transport audio signal in wireless medium. A song is played in a smartphone. Using the headphone jack, the audio signal is first amplified using PAM8403 analog amplifier and then superimposed on LASER light. The modulated signal is transmitted in wireless medium and received on a solar panel. The amplitude variation in received signal can be detected by a speaker which recovers the song.  As soon as the song is played, the receiver detects it and sends a text message to a cell phone number using GSM800 module. Another text is sent when transmission is stopped. (The text messaging part is not shown in the following video)