Smart Motion Light – ENGR 478 Final Project

This page presents our Smart Motion Light project, an embedded systems application designed to improve energy efficiency through motion-based lighting control. Using the STM32L476RG microcontroller, we integrated sensors, interrupts, timers, and PWM to create a responsive and automated lighting system. This project highlights core embedded systems concepts applied to a real-world problem.

Smart motion light explained

This project demonstrates how an embedded system can automatically control lighting using motion detection and timing logic. A PIR sensor triggers the system when motion is detected, and the microcontroller adjusts LED brightness over time using PWM. The design emphasizes efficient power usage, smooth brightness transitions, and interrupt-driven control.

Key features

The Smart Motion Light includes several key features that enhance both functionality and efficiency:

  • Motion detection using a PIR sensor and external interrupts

  • Multi-stage brightness control based on inactivity timing

  • PWM-based LED dimming with smooth fade transitions

  • Optional ambient light sensing using a photoresistor (ADC)
    These features work together to create a reliable and energy-conscious lighting system.

Visual resources

This section provides visual references that support the development and testing of the project. Images and diagrams include hardware connections, system architecture, and demonstrations of the lighting behavior. These resources help illustrate how the hardware and software components interact within the Smart Motion Light system.