Humidity and temperature (DHT11/DHT22) in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to include the DHT sensor library.

Arduino

#include [1]

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A<Wire.h>

B<DHT.h>

C<SPI.h>

D<Servo.h>

Attempts:

3 left

💡 Hint

Common Mistakes

Including the wrong library like Wire.h or SPI.h which are for other sensors.

Forgetting the angle brackets <> around the library name.

The DHT sensor library is included with #include to use the DHT11 or DHT22 sensors.

2fill in blank

medium

Complete the code to define the DHT sensor type as DHT22.

Arduino

#define DHTTYPE [1]

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ADHT11

BDHT12

CDHT22

DDHT33

Attempts:

3 left

💡 Hint

Common Mistakes

Using DHT11 when the sensor is actually DHT22.

Using undefined sensor types like DHT33.

Defining DHTTYPE as DHT22 tells the code which sensor model is used.

3fill in blank

hard

Fix the error in initializing the DHT sensor object on pin 2.

Arduino

DHT dht([1], DHTTYPE);

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A2

BDHTTYPE

C3

DDHT

Attempts:

3 left

💡 Hint

Common Mistakes

Using the sensor type or class name instead of the pin number.

Using a pin number that does not match the hardware connection.

The first argument is the pin number where the sensor data line is connected, here pin 2.

4fill in blank

hard

Fill both blanks to read humidity and temperature values from the sensor.

Arduino

float humidity = dht.[1]();
float temperature = dht.[2]();

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AreadHumidity

BreadTemperature

CreadTemp

DgetHumidity

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect function names like readTemp or getHumidity which do not exist.

Mixing up humidity and temperature function calls.

Use readHumidity() to get humidity and readTemperature() to get temperature from the sensor.

5fill in blank

hard

Fill all three blanks to check if readings are valid and print them to the serial monitor.

Arduino

if (isnan([1]) || isnan([2])) {
  Serial.println("Failed to read from DHT sensor!");
  return;
}
Serial.print("Humidity: ");
Serial.print([3]);
Serial.println(" %");

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Atemperature

Bhumidity

Dtemp

Attempts:

3 left

💡 Hint

Common Mistakes

Checking variables that do not exist or are misspelled.

Printing temperature instead of humidity in the last print statement.

We check if humidity or temperature is NaN (not a number) to detect errors. Then we print humidity value.