PIR motion sensor in Arduino - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does a PIR motion sensor detect?

A PIR (Passive Infrared) motion sensor detects changes in infrared radiation, which usually means it senses movement of warm objects like humans or animals.

beginner

How do you connect a PIR sensor to an Arduino?

Connect the PIR sensor's VCC pin to 5V on Arduino, GND to ground, and the output pin to a digital input pin on the Arduino (e.g., pin 2).

beginner

What Arduino function reads the PIR sensor output?

Use the digitalRead() function on the Arduino pin connected to the PIR sensor output to check if motion is detected (HIGH) or not (LOW).

intermediate

Why is it important to add a delay after detecting motion with a PIR sensor?

Adding a delay helps prevent multiple rapid triggers and gives the sensor time to stabilize before detecting new motion.

beginner

What is the typical output signal of a PIR sensor when motion is detected?

The PIR sensor output goes HIGH (usually 3.3V or 5V) when motion is detected, and LOW when no motion is present.

What type of signal does a PIR sensor output to the Arduino when motion is detected?

A Digital HIGH signal

B Analog voltage proportional to distance

C PWM signal

D No signal

The PIR sensor outputs a digital HIGH signal when it detects motion.

Which Arduino function is used to read the PIR sensor's output pin?

A pulseIn()

B analogRead()

C digitalWrite()

D digitalRead()

digitalRead() reads the digital signal from the PIR sensor output pin.

Why should you add a delay after detecting motion with a PIR sensor?

A To increase sensor sensitivity

B To reset the Arduino

C To prevent multiple rapid triggers

D To save power

Adding a delay prevents multiple rapid triggers and allows the sensor to stabilize.

What voltage is typically used to power a PIR sensor with Arduino?

A 5V

B 3.3V only

C 12V

D 1.5V

Most PIR sensors work well with 5V power from the Arduino.

What does PIR stand for in PIR motion sensor?

A Proximity Infrared

B Passive Infrared

C Power Infrared

D Pulse Infrared

PIR stands for Passive Infrared, meaning it detects infrared radiation passively.

Explain how a PIR motion sensor works with an Arduino to detect movement.

Think about how the sensor senses heat changes and how Arduino reads that.

Describe the steps to connect and program a PIR sensor with Arduino for a simple motion detection project.

Start from wiring, then how to read and respond to sensor signals.