Interface DHT11 temperature sensor with NodeMCU ESP8266

DHT11

/* By TrickSumo.com
Libraries used:- 
https://github.com/adafruit/DHT-sensor-library
https://github.com/adafruit/DHT-sensor-library
*/

#include <DHT.h>   

#define DHTTYPE DHT11                                               



#define dht_dpin D1
DHT dht(dht_dpin, DHTTYPE);                                                  

void setup() {

  dht.begin();    
  Serial.begin(9600);

  Serial.println("Serial Communication Started\n");  

}

void loop() { 
  float h = dht.readHumidity();                                            
  float t = dht.readTemperature();                                          
    
  if (isnan(h) || isnan(t)) {                                               
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

Serial.print("Humidity = ");
    Serial.print(h);
    Serial.print("\n ");
    Serial.print("Temperature = ");
    Serial.print(t); 
    Serial.println("C \n \n \n ");
  delay(2000 );


}

Works fine. Thank you

You're Welcome :)

Works fine. Thank you

You're Welcome :)

i was try dht11 with arduino uno and thats works fine, but when i try dht11 with esp8266 the output is nan. so where is the problem? and what i must to do for fix this problem?

Hi @yocki24

Its not working because DHT11 need 5V input.

Either you can use VV pin of NodeMCU ESP8266 or 9V battery with 7805 voltage regulator ic.

https://www.youtube.com/watch?v=pA_Rfop7kDc&list=PLqbNDdqyX9E0H_V-X80L_iFvFtG431Lqd&index=4

Let me know if it helps!

Hi @yocki24

Its not working because DHT11 need 5V input.

Either you can use VV pin of NodeMCU ESP8266 or 9V battery with 7805 voltage regulator ic.

https://www.youtube.com/watch?v=pA_Rfop7kDc&list=PLqbNDdqyX9E0H_V-X80L_iFvFtG431Lqd&index=4

Let me know if it helps!

i was try it but the output still failed

Weird!

Tried with battery also? https://www.youtube.com/watch?v=hPv9uX3rUWc&t=3s

Are you using same code mentioned above?

hmm not yet
i just tried without battery

oh ok. Try with +5v, it will work.

For without battery, refer this:-

NodeMCU Amica model
https://github.com/TrickSumo/water-level-indicator-controller/blob/master/Circuit%20Diagram%20For%20NodeMCU%20ESP8266%20Amica%20Model.JPG

NodeMCU Lolin model
https://github.com/TrickSumo/water-level-indicator-controller/blob/master/Circuit%20Diagram%20For%20NodeMCU%20ESP8266%20LoLin%20Model.jpg

If your NodeMCU do not have VV or Vin (or sensor not working even with those). Then using battery with voltage regulator is best solution.

oh ok. thanks about that

i want ask one question, should i use a resistor for dht11 sensor?

should i use a resistor for dht11 sensor

If you are using 7805 IC with battery then no need to use resistor.

Else you can use battery and two resistors as voltage divider (or use rheostat).

In any case make sure to not feed digital IC's (including some sensors) more than 5v.

ok, i was search a scematic design and i found it use resistor in data pin. so should i doing this?

You can use it.

oke thank you so much

Welcome :)