PIR motion sensor in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the PIR sensor pin as input.

Arduino

const int pirPin = 7;

void setup() {
  pinMode([1], INPUT);
}

void loop() {
  // Your code here
}

Drag options to blanks, or click blank then click option'

ApirPin

B7

COUTPUT

DLED_BUILTIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using the pin number directly instead of the variable.

Setting the pin mode to OUTPUT instead of INPUT.

You need to set the PIR sensor pin as input using pinMode(pirPin, INPUT); where pirPin is the variable holding the pin number.

2fill in blank

medium

Complete the code to read the PIR sensor value.

Arduino

int sensorValue = digitalRead([1]);

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AINPUT

BpirPin

CLED_BUILTIN

D8

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong pin number.

Passing INPUT instead of a pin number.

To read the PIR sensor value, use digitalRead(pirPin); where pirPin is the pin connected to the sensor.

3fill in blank

hard

Fix the error in the code to turn on the built-in LED when motion is detected.

Arduino

if (sensorValue == [1]) {
  digitalWrite(LED_BUILTIN, HIGH);
} else {
  digitalWrite(LED_BUILTIN, LOW);
}

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ALOW

B0

CHIGH

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for LOW or 0 instead of HIGH or 1.

Using the wrong constant for comparison.

The PIR sensor outputs HIGH (1) when motion is detected, so the condition should check for 1.

4fill in blank

hard

Fill both blanks to create a dictionary that maps sensor states to messages.

Arduino

const char* messages[] = {"No motion", [1];

void loop() {
  int state = digitalRead(pirPin);
  Serial.println(messages[[2]]);
}

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A"Motion detected"

Bstate

CsensorValue

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong message string.

Using a constant like 1 instead of the state variable.

The array holds messages for states 0 and 1. Use "Motion detected" for {{BLANK_1}} and state for {{BLANK_2}} to print the correct message based on the sensor state.

5fill in blank

hard

Fill all three blanks to complete the code that initializes serial communication, reads the PIR sensor, and prints the status.

Arduino

void setup() {
  Serial.[1](9600);
  pinMode(pirPin, INPUT);
}

void loop() {
  int [2] = digitalRead(pirPin);
  Serial.println([3] == 1 ? "Motion detected" : "No motion");
  delay(500);
}

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Abegin

BsensorState

Dprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using print instead of begin to start serial.

Using different variable names for reading and printing.

Use Serial.begin(9600); to start serial communication. Read the sensor into sensorState and print the message based on its value.