Smart Contactless Water Dispensing and Monitoring System with Dual-Platform Notification via Blynk and Telegram

Abstract

Conventional water dispensing systems may lack hygienic operation, real-time monitoring, and energy efficiency, particularly in public and educational settings. The objective of this research was to design a smart, contactless, and solar-powered water-dispensing and monitoring system using Internet of Things (IoT) technology. The designed system uses an ESP32 microcontroller with dual ultrasonic sensors for water-level monitoring and hand detection, and a DS18B20 sensor for temperature measurement. The system uses threshold-based control logic to automatically disable  dispensing function under low-water conditions while activating local alerts through LEDs and a buzzer. Real-time data is recorded in Google Sheets, while remote monitoring and notifications are provided through Blynk and Telegram. The system also incorporates a regulated solar-battery subsystem to support off-grid operation. Experimental results demonstrated the successful operation of the system in hand detection, water-level measurement, cloud-based data logging, remote notifications and off-grid power supply.