IR sensor for obstacle detection in Arduino - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does an IR sensor detect in obstacle detection?

An IR sensor detects infrared light reflected from nearby objects to sense obstacles.

beginner

How do you connect an IR sensor to an Arduino for obstacle detection?

Connect the IR sensor's VCC to 5V, GND to ground, and the output pin to an Arduino digital input pin.

beginner

What Arduino function reads the IR sensor output?

Use digitalRead(pin) to read the sensor's output pin, which tells if an obstacle is detected.

beginner

Why do we use an if statement with the IR sensor reading?

To check if the sensor output indicates an obstacle and then take action like stopping a motor.

beginner

What is a simple Arduino code snippet to detect an obstacle using an IR sensor?

int sensorPin = 7; void setup() { pinMode(sensorPin, INPUT); Serial.begin(9600); } void loop() { int val = digitalRead(sensorPin); if (val == LOW) { Serial.println("Obstacle detected!"); } else { Serial.println("No obstacle."); } delay(500); }

What does the IR sensor output when it detects an obstacle?

A HIGH signal

B Analog voltage

C No signal

D LOW signal

Most IR sensors output a LOW digital signal when an obstacle is detected.

Which Arduino function reads a digital pin connected to an IR sensor?

A digitalRead()

B pinMode()

C analogRead()

D Serial.read()

digitalRead() reads the digital value (HIGH or LOW) from a specified pin.

What is the purpose of the delay() function in the IR sensor code?

A To reset the sensor

B To speed up sensor reading

C To pause between readings for stability

D To change sensor sensitivity

delay() pauses the program to avoid reading the sensor too fast and to stabilize output.

Which pin mode should be set for the IR sensor output pin on Arduino?

A INPUT

B ANALOG

C INPUT_PULLUP

D OUTPUT

The sensor output pin should be set as INPUT to read its signal.

What happens if you connect the IR sensor output to an analog pin and use digitalRead()?

A It reads LOW always

B It may not read correctly

C It works fine

D It damages the Arduino

digitalRead() on an analog pin may not give reliable results; use analogRead() for analog signals.

Explain how an IR sensor detects obstacles and how you use it with Arduino.

Think about how light bounces back and how Arduino reads that signal.

Describe a simple Arduino program structure to detect obstacles using an IR sensor.

Focus on the main parts of an Arduino sketch for sensor reading.