Visible light communication system. During my holiday, I worked on a project using an Arduino, an ultrasonic sensor, and bright spotlights to send messages using light instead of the internet. The light is turned ON and OFF in a pattern. ON means 1 OFF means 0 These ON and OFF signals are called bits. Every 8 bits make one letter or symbol. I also created an Android app using android studio. The app uses the phone's camera to read the blinking light. It changes the light signals into bits and th