IR sensor for obstacle detection in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read the IR sensor value.

Arduino

int sensorValue = analogRead([1]);

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A13

BA0

C5

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using a digital pin number instead of an analog pin.

Forgetting to use analogRead for analog sensors.

The IR sensor is connected to analog pin A0, so we use analogRead(A0) to get its value.

2fill in blank

medium

Complete the code to set the IR sensor pin as input in setup().

Arduino

pinMode([1], INPUT);

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AA0

B13

C7

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the wrong pin as input.

Using digital pins instead of the analog pin connected to the sensor.

The IR sensor is connected to analog pin A0, which should be set as input using pinMode(A0, INPUT);.

3fill in blank

hard

Fix the error in the if statement to detect obstacle when sensor value is less than threshold.

Arduino

if (sensorValue [1] threshold) {
  Serial.println("Obstacle detected");
}

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

A<

B==

C>

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than operator which triggers detection incorrectly.

Using equality operator which rarely matches exactly.

When the IR sensor detects an obstacle, the sensor value is usually less than the threshold, so the condition should be sensorValue < threshold.

4fill in blank

hard

Fill both blanks to complete the code that reads sensor and prints "No obstacle" when value is above threshold.

Arduino

sensorValue = analogRead([1]);
if (sensorValue [2] threshold) {
  Serial.println("No obstacle");
}

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

AA0

B<

C>

D13

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong pin number.

Using less than operator which means obstacle detected.

The sensor is read from analog pin A0, and when the value is greater than the threshold, it means no obstacle is detected.

5fill in blank

hard

Fill all three blanks to create a dictionary-like structure that maps sensor states to messages.

Arduino

const char* messages[] = {"[1]", "[2]"};
int sensorValue = analogRead(A0);
Serial.println(sensorValue [3] threshold ? messages[0] : messages[1]);

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

AObstacle detected

BNo obstacle

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the messages order.

Using wrong comparison operator.

The messages array holds the two messages. The condition uses < to check if sensorValue is below threshold, printing "Obstacle detected" if true, otherwise "No obstacle".