Ultrasonic distance sensor (HC-SR04) in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the trigger pin for the HC-SR04 sensor.

Arduino

const int trigPin = [1];

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A2

B5

C13

D9

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing an analog pin instead of a digital pin for the trigger.

Using the same pin number for both trigger and echo.

The trigger pin is set to digital pin 9 to send the ultrasonic pulse.

2fill in blank

medium

Complete the code to set the echo pin as an input in the setup function.

Arduino

pinMode([1], INPUT);

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AechoPin

BtrigPin

CledPin

DbuttonPin

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the trigger pin as input instead of output.

Using a pin variable that is not defined.

The echo pin must be set as an input to read the returning ultrasonic pulse.

3fill in blank

hard

Fix the error in the code to send a 10 microsecond pulse to the trigger pin.

Arduino

digitalWrite(trigPin, HIGH);
delayMicroseconds([1]);
digitalWrite(trigPin, LOW);

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A1

B100

C10

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using delay() instead of delayMicroseconds().

Using too long or too short pulse duration.

The HC-SR04 sensor requires a 10 microsecond pulse on the trigger pin to start measurement.

4fill in blank

hard

Fill both blanks to correctly calculate the distance in centimeters from the duration.

Arduino

long duration = pulseIn([1], HIGH);
float distance = duration [2] 58.2;

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AechoPin

B*

C/

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Multiplying duration instead of dividing.

Using the trigger pin instead of echo pin for pulseIn.

The pulseIn function measures the time on the echo pin. Distance is calculated by dividing duration by 58.2.

5fill in blank

hard

Fill all three blanks to complete the loop that reads distance and prints it to the serial monitor.

Arduino

digitalWrite([1], LOW);
delayMicroseconds(2);
digitalWrite([2], HIGH);
delayMicroseconds(10);
digitalWrite([2], LOW);

long duration = pulseIn([3], HIGH);
float distance = duration / 58.2;
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");

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AtrigPin

BechoPin

Attempts:

3 left

💡 Hint

Common Mistakes

Using echo pin to send pulse instead of trigger pin.

Mixing up the order of setting pins HIGH and LOW.

The trigger pin is first set LOW, then HIGH for 10 microseconds, then LOW again to send the pulse. The echo pin is used to measure the pulse duration.