Smartphone Based Liquid Level Monitoring System

The Smartphone Based Liquid Level Monitoring System operates by utilizing an Arduino Uno as the central processing unit to measure and transmit fluid levels in real time. At the core of the sensing mechanism is the HC-SR04 ultrasonic sensor module, which is mounted above the test container. The Arduino Uno triggers the ultrasonic sensor to emit high-frequency sound waves downward toward the liquid surface. As these sound waves bounce off the liquid and return as echoes, the sensor measures the time of flight. The Arduino processes this timing data to calculate the exact distance between the sensor and the liquid surface, which can then be mapped to determine the actual volume or height of the liquid remaining in the container. Once the distance measurement is computed by the microcontroller, the system packages this data for wireless transmission. The HC-05 Bluetooth module, wired to the serial communication pins of the Arduino Uno, takes the processed data and streams it wirelessly over a short-range radio frequency connection to an Android smartphone. On the receiving end, a custom application built via MIT App Inventor (levelmonitoring.apk) pairs with the HC-05 module, decodes the incoming serial data stream, and presents the live liquid level visually to the user on their phone screen. This integration of local ultrasonic sensing, microcontroller calculation, and wireless Bluetooth telemetry allows users to monitor fluid containers remotely without needing to physically check the tank.