Adaptive LED Lighting Based on Ambient Light & Motion

Projects General Guidance
1

Hi everyone,

I’m working on a small Arduino project to control LED lighting based on ambient light levels and motion detection.

Goal

Create a system where:

LEDs gradually turn on when the room gets dark

LEDs brighten only when someone is in the room

LEDs fade off after no motion is detected for a set time

Hardware

Arduino Uno (or Nano)

LDR (photoresistor) or BH1750 light sensor

PIR motion sensor

WS2812 or simple RGB LEDs + resistors

Optional: potentiometer to adjust sensitivity

Current Setup

I have the sensors connected and reading values, but I’m stuck on:

Smoothing the ambient light readings (so lights don’t flicker)

Combining motion + light threshold logic

What I’d Like Help With

Example code snippet to read the light sensor and debounce flicker

Tips on managing power/LED brightness smoothly (PWM or library suggestions)

Best way to structure the logic (ambient threshold vs motion trigger)

Any suggestions or example sketches would be appreciated!

Thanks

2

For Neopixel, you can use the Adafruit_NeoPixel or FastLED library. Smooth fades using built-in color blending or manual interpolation.

3

This looks like a school assignment.

What is the deadline for submitting the project?

4

This results in the room never getting dark.

This will immediately go to the first state of LEDs ON.

Show the code you are stuck on, and a drawing of the wiring.

5

The BH1750 has 50/60Hz rejection filters so smoothing is not necessary.

6

OP has a habit of posting then disappearing.