In this tutorial, we will interface DHT-11 with NodeMCU. To setup NodeMCU board in Arduino software visit this post.
CONNECTIONS :
NodeMCU DHT11
5v - 5v
Gnd - Gnd
D4 - Data pin
PROCEDURE:
- Download the Dht library from https://github.com/adafruit/DHT-sensor-library
- While compiling if it shows Adafruit_Sensor.h missing download it from https://github.com/adafruit/Adafruit_Sensor
- Extract the libraries and paste it into the library folder of Arduino(It will be in C:/Program Files (x86)/Arduino/libraries)
- You can open the example program from File–>Examples–>DHT Sensor Library–>DHTtester
PROGRAM:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | #include "DHT.h" #define DHTPIN D4 #define DHTTYPE DHT11 // DHT 11 DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(9600); Serial.println("DHTxx test!"); dht.begin(); } void loop() { // Wait a few seconds between measurements. delay(2000); // Reading temperature or humidity takes about 250 milliseconds! // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor) float h = dht.readHumidity(); // Read temperature as Celsius (the default) float t = dht.readTemperature(); // Read temperature as Fahrenheit (isFahrenheit = true) float f = dht.readTemperature(true); // Check if any reads failed and exit early (to try again). if (isnan(h) || isnan(t) || isnan(f)) { Serial.println("Failed to read from DHT sensor!"); return; } // Compute heat index in Fahrenheit (the default) float hif = dht.computeHeatIndex(f, h); // Compute heat index in Celsius (isFahreheit = false) float hic = dht.computeHeatIndex(t, h, false); Serial.print("Humidity: "); Serial.print(h); Serial.print(" %\t"); Serial.print("Temperature: "); Serial.print(t); Serial.print(" *C "); Serial.print(f); Serial.print(" *F\t"); Serial.print("Heat index: "); Serial.print(hic); Serial.print(" *C "); Serial.print(hif); Serial.println(" *F"); } |
OUTPUT:
To send DHT-11 data to Thingspeak cloud visit here. And to visualize DHT-11 data in Ubidots dashboard visit here.
Thankyou
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