#09intermediate

Motion Guardian

PIR-based motion detection alarm system

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

Components

Everything you need for this project.

1x HC-SR501 PIR sensor

1x Active buzzer

1x Red LED

220Ω

1x 220Ω resistor

4x jumper wires

How It Works

PIR sensor operation (passive infrared), digital input from a sensor module, timing and timeout logic, and alarm system design.

InputPIR Motion Sensor
ProcessingESP32-S3 reads digital HIGH on motion detection
OutputAlarm: LED + buzzer

What You Build

PIR sensor on D1, red LED on D2, buzzer on D3. Motion triggers a timed alarm sequence.

African Context

Simple motion alarms protect homes, shops, and farm stores. This circuit is the basis of security systems used across urban and rural Africa.

What You'll See

Walking past the sensor triggers the LED and buzzer for a set duration. Display shows detection events and countdown timer.