MRM MRM MRM MRM
SYSTEM BOOTING
Let's talk
Back to projects
Electronics

AutoLux — Smart LED Street Light Controller

An automatic dusk-to-dawn LED street light controller switching purely on ambient light via an LDR and MOSFET.

Difficulty — beginner Complexity — 3/10 Category — Electronics
assets/projects/autolux.jpg
assets/projects/autolux-2.jpg
assets/projects/autolux-3.jpg

Overview

An automatic street-lighting circuit that switches LEDs on at dusk and off at dawn using nothing but an LDR voltage-divider and MOSFET switching — a simple, energy-efficient automation circuit validated across a range of simulated ambient light levels.

Architecture

LDR voltage-divider sensing → threshold comparison → IRF540 MOSFET switching → LED load actuation.

Key Features

  • LDR-based ambient light sensing via voltage-divider configuration.
  • MOSFET-triggered switching for energy-efficient LED actuation.
  • Validated dusk-to-dawn automation behavior across light-level variation.

Development Process

  • Selected LDR and voltage-divider values to set a sensible light-level switching threshold.
  • Added MOSFET switching to drive the LED load from the sensed threshold.
  • Simulated across a range of ambient light levels to confirm stable switching behavior.

Challenges & Solutions

Challenge

A poorly chosen switching threshold could cause the light to flicker at twilight ambient levels.

Solution

Tuned the voltage-divider ratio to give a clean, non-oscillating switching point in simulation.

Results & Impact

The circuit reliably switched LED lighting on and off at appropriate ambient light thresholds with stable, energy-efficient operation in simulation.

Future Improvements

  • Add PWM dimming based on ambient light gradient.
  • Add a physical prototype with real LDR hardware.
  • Integrate with the SCADA system for remote monitoring.