#03beginner

Night Guardian

An automatic nightlight that turns on when it gets dark

Watch the circuit build itself: components drop in, wires connect, and the output comes alive.

Components

Everything you need for this project.

1x LDR (GL5528)

10KΩ

1x 10KΩ resistor

1x Green LED

220Ω

1x 220Ω resistor

4x jumper wires

How It Works

Analog input (ADC), threshold-based decision making, and the voltage divider concept using a light-dependent resistor.

InputLDR (light sensor)
ProcessingESP32-S3 reads ADC value, compares to threshold
OutputLED turns on in darkness

What You Build

Voltage divider with LDR and 10K resistor on pin A1. An LED on D1 turns on automatically when light decreases.

African Context

Automatic street lighting saves energy in communities with limited power. Solar-powered auto-lights using LDR circuits are deployed across rural Africa.

What You'll See

Covering the LDR lights the LED. Display shows real-time ADC value (0–4095) and a light level bar graph.