PIR Motion Sensor Module

Part images

What it is

A PIR motion sensor detects changes in infrared radiation from warm moving bodies.

How students use it

Students use it for intruder alarms, passage counters, wake-up triggers, and projects that react when someone moves nearby.

Pins and power

Typical module pins are VCC, output signal, and GND. Verify the labels on the actual board before wiring.

Module-powered digital sensor. Verify the module supply and output voltage before connecting the signal pin to Pico GPIO.

SunFounder notes a one-minute initialization period, distance and delay adjustment potentiometers, and H/L trigger-mode jumper behavior.

Voltage and safety

Confirm the output level is Pico-safe. If a module outputs 5V high, use level shifting before GPIO.

Keep heat sources, bright light changes, and moving air away from the sensor surface during tests to avoid false triggers.

Module internals

Main component: Passive infrared sensing element and module circuitry; SunFounder does not list a manufacturer part number.

PIR sensing element, Fresnel lens, differential amplifier module, distance potentiometer, delay potentiometer, H/L trigger-mode jumper, header pins, and support passives.

Datasheet notes

SunFounder lists adjustable sensing distance from about 0-3m minimum to about 0-7m maximum, and delay from about 5s to 300s.

Common libraries

No special library is needed. Use machine.Pin to read the motion output and treat initialization/delay as part of the sensor behavior.

Common mistakes

Testing before warm-up completes, aiming at moving curtains/fans, confusing H and L trigger modes, and expecting it to detect still people.