Automatic Dusk-to-Dawn Switching Without a Microcontroller

The Relay Light Controlled Module combines a light sensor and a relay on one board, so it can switch a load when the surrounding light level changes. That means you can build simple dusk-to-dawn or light-triggered systems without adding a separate microcontroller.

It is a useful module for outdoor lights, night indicators, greenhouse controls, and energy-saving projects that need automatic response to ambient light.

Why you'll like it

• Works on its own: No controller needed for basic light-triggered switching
• Adjustable sensitivity: Tune the light threshold on the board
• Relay output onboard: Easy switching for AC or DC loads within rating
• Fast to install: Good for simple automation jobs
• Good for day/night projects: Useful in outdoor or window-side builds

What you can build

Use it for dusk-to-dawn lamps, sign lighting, greenhouse shade control, nighttime alarms, and other simple projects that react to ambient light.

Starter bundles

Pair it with an Arduino-compatible board, ESP32, or Raspberry Pi, plus jumper wires, a suitable power supply, and a small load for bench testing.

Recommended add-ons

Useful add-ons include terminal block, breadboard, power modules, fuses, and enclosure, especially when you are working with higher voltages or inductive loads.

Technical specifications

Pinout & power notes

Power the module from its rated supply, adjust the onboard potentiometer, then wire the target device to the relay output. Test the trigger point under real lighting conditions before final installation.

What’s in the box

1 × Relay Light Controlled Module

Frequently Asked Questions