LiFi Based Real Time Under Water Board Casting from Optimal Data Rates and Low Power Consumptions

This project presents a Li-Fi–based underwater communication prototype designed to efficiently transmit water-quality data using low power and optical signaling. The system consists of separate Transmitter (TX) and Receiver (RX) modules. The TX module, placed underwater, uses sensors such as the HC-SR04 ultrasonic sensor for water level, pH sensor, DS18B20 temperature sensor, and turbidity sensor to monitor environmental conditions, while a buzzer provides alerts during abnormal readings. The collected data is encoded and sent through a Li-Fi LED transmitter. At the surface, the RX module uses an LDR-based Li-Fi receiver to decode the optical signal, display the information on an LCD, and indicate the status using green (normal) and red (abnormal) LEDs. Additional sensors like DHT11, MQ135, and LDR enhance monitoring at the receiver side. A push button allows the data to be uploaded to the ThingSpeak cloud using NodeMCU. The proto- type demonstrates the effectiveness of Li-Fi as a low-power, interference-free solution for underwater communication, making it suitable for various water-quality monitoring applications.one important feature for scuba divers,whenever they found a danger,they can send ‘help!’ signal to receiver and activates the buzzer.