// Example testing sketch for various DHT humidity/temperature sensors // Written by ladyada, public domain #include "DHT.h" #define DHTPIN 2 // what pin we're connected to // Uncomment whatever type you're using! //#define DHTTYPE DHT11 // DHT 11 #define DHTTYPE DHT22 // DHT 22 (AM2302) //#define DHTTYPE DHT21 // DHT 21 (AM2301) // Connect pin 1 (on the left) of the sensor to +5V // Connect pin 2 of the sensor to whatever your DHTPIN is // Connect pin 4 (on the right) of the sensor to GROUND // Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(9600); Serial.println("DHTxx test!"); dht.begin(); } void loop() { // 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(); float t = dht.readTemperature(); // check if returns are valid, if they are NaN (not a number) then something went wrong! if (isnan(t) || isnan(h)) { Serial.println("Failed to read from DHT"); } else { Serial.print("Humidity: "); Serial.print(h); Serial.print(" %\t"); Serial.print("Temperature: "); Serial.print(t); Serial.println(" *C"); } }