RECONFIGURABLE FPGA-DRIVEN SMART FLUSH SENSE: A PARADIGM SHIFT IN CONTACTLESS SANITATION AUTOMATION

Abstract

The Smart Flush Sense system heralds a disruptive innovation in next-generation san-itation, leveraging the reconfigurable architecture of an Edge Artix 7 FPGA to orchestrate a contactless, water-efficient restroom automation framework. This cyber-physical system integrates heterogeneous sensor fusion, employing three infrared (IR) sensors to achieve deterministic latency in detecting user presence and adaptive gesture recognition. Pro-grammed in Verilog HDL, a sophisticated finite state machine (FSM) governs state-space transitions across idle, handwash, auto-flush, manual flush, and reset modalities, ensuring sub-100 ms response times and fault-tolerant operation. A servo motor, driven by precise pulse-width modulation (PWM), actuates flushing at a 180° trajectory, while a centrifugal pump optimizes tap flow at a 90° angle, both constrained by a 2-second temporal window to minimize water consumption. The system’s power-efficient design (¡5W) and robust temporal logic calibration mitigate challenges such as IR sensor crosstalk and ambient light interference, enhancing operational reliability. Unlike conventional microcontroller-based architectures, this FPGA-driven solution offers unparalleled scalability, enabling seamless integration of advanced features like usage analytics or AI-driven gesture refine-ment. Scalable for deployment in high-traffic environments such as hospitals, educational institutions, and commercial complexes, Smart Flush Sense exemplifies a sustainable, hy-gienic paradigm, reducing water usage by approximately 67% per flush ( 1L vs. 3L) and eliminating contact-related pathogen transmission risks. This work underscores FPGA’s transformative potential in smart sanitation, paving the way for modular, reconfigurable automation in resource-constrained settings.