Design and Implementation of a Low-Battery Powered IoT-Based Smart Trash Can System with Wireless Alerts

Accurate and persistent time stamping is a fundamental requirement in smart infrastructure and Internet of Things applications, particularly in systems that must tolerate power interruptions and operate under low power duty cycles. This paper presents an ESP32 based smart trash bin designed to monitor lid opening events, record usage behavior, and mitigate odor dispersion in densely populated residential environments such as apartment buildings. The system detects lid state using an infrared obstacle sensor and acquires precise date and time information from a DS3231 real time clock through an I2C interface. Upon lid opening, the time stamp is displayed locally on an LCD mounted on the trash bin and stored in the ESP32 internal flash memory to preserve records across resets or unexpected power loss. Time stamp data are also transmitted through Bluetooth Low Energy and visualized using the nRF Connect mobile application for short range monitoring and validation. When the lid remains open beyond a predefined threshold of five minutes, the system generates a prolonged opening event and transmits an alarm notification through WiFi to the Blynk mobile application to support timely intervention by security personnel or facility management. The hardware is powered by a battery supply and the ESP32 enters deep sleep mode after lid closure to minimize energy consumption while maintaining event driven wake up capability. Experimental results confirm reliable time stamp logging, consistent multi-interface visualization, robust wireless reporting, and effective low power operation, demonstrating the suitability of the proposed system for practical smart residential waste management applications.