What is DHT11 temperature and humidity sensor ?

Application in practice like?

What sensor do you use?

These are questions that newcomers want to know.

Through today's article we learn together offline.

DHT11 temperature and humidity sensor

DHT11 humidity and temperature sensors are very popular sensors because they are cheap and easy to get data through the standard 1-wire interface.

The standard of 1 wire communication is to use 1 digital pin to transfer data.

The signal preprocessor is built into the sensor so you can read the data accurately without any calculations.

DHT11 temperature and humidity sensor module

Sensor specifications:

• Operating voltage: 3V - 5V (DC)
• Operating humidity range: 20% - 90% RH, error of ± 5% RH
• Operating temperature range: 0 ° C ~ 50 ° C, tolerance ± 2 ° C
• Maximum transmission distance: 20m

You download and install the library to support using DHT11: Here

• See also: Instructions on how to install the library on the Arduino IDE.

Connection diagram

The necessary components for the project:

• Arduino UNO: >> View product here.
• DHT11 temperature, humidity sensor:  >> View product here.

Code

#include  "DHT.h"             
const  int  DHTPIN  =  4 ;       
const  int  DHTTYPE  =  DHT11 ;  
 
DHT  dht ( DHTPIN ,  DHTTYPE ) ; 
void  setup ( )  { 
  Serial . begin ( 9600 ) ; 
  dht . begin ( ) ;        
}
 
void  loop ( )  {
   float  h  =  dht . readHumidity ( ) ;     
  float  t  =  dht . readTemperature ( ) ; 
 
  Serial . print ( "Due:" ) ; 
  Serial . println ( t ) ;                
  Serial . print ( "Do am:" ) ; 
  Serial . println ( h ) ;  
              
  Serial . println ( ) ;                
  delay ( 1000 ) ;                      
}

 Explain the code

Declare connection pin for DHT sensor here I use pin D4 on Arduino Uno.

const  int  DHTPIN  =  4 ; const  int  DHTTYPE  =  DHT11 ;

DHT.h library is declared to be used for 2 types of sensors: DHT11 and DHT22.

In our article, we introduce the DHT11 temperature and humidity sensor , so we need to declare that DHTTYPE is DHT11.

 float  h  =  dht . readHumidity ( ) ;   // Read temperature value from float  sensor  t  =  dht . readTemperature ( ) ; // Read humidity value from the sensor

Above are two variables that read the temperature and humidity values.

Serial . print ( "Due:" ) ; Serial . println ( t ) ;  Serial . print ( "Do am:" ) ; Serial . println ( h ) ;              
 

Print temperature and humidity values on the screen (Serial Monitor).

• To understand more about the functions Serial.print () and  Serial.println (), please see the article here: See now.

We proceed to Upload the program and turn on Serial Monitor to see the results.