Explain Like I'm 12
PIR sensor is like a guard that watches for movement. When someone walks by, it sends a signal to your ESP32 — perfect for security alarms or automatic lights.
Technical Specifications
Arduino library: Built-in digitalRead
- Detection range: up to 7 m
- Operating voltage: 5 V to 20 V
- Digital output: HIGH when motion detected
- Adjustable sensitivity and delay
Pinout
- VCC → 5 V
- GND → GND
- OUT → GPIO27
Wiring
Connect each pin as shown in the pinout section above.
Wiring Diagram
Wiring diagram for HC-SR501 PIR Motion Sensor
Code Example
Copy into Arduino IDE. Install the library listed above first.
example.ino
#define PIR 27
void setup() { Serial.begin(115200); pinMode(PIR, INPUT); }
void loop() {
if (digitalRead(PIR) == HIGH) Serial.println("Motion detected!");
delay(200);
}Expected Output
Serial Monitor prints "Motion detected!" when someone moves nearby.
Related Projects
FAQ
Point it away from heat sources like windows and adjust sensitivity screw.
Downloads
Official manufacturer PDF for teachers and advanced builders.
Datasheet coming soon.