8.3 Digital Temperature
Temperature and Humidity Sensor - DHT11
// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, slightly modified, 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)
DHT dht(DHTPIN, DHTTYPE);
void setup() {
Serial.begin(9600);
Serial.println("DHT 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 {
// Uncomment these lines if you prefer to use the Fahrenheit scale
// instead of Celsius. Remember to change line 44 so that the
// symbol is "F" instead of "C"
// float fahrenheitTemp = t * 9.0/5.0+32.0;
// Serial.print("Temperature: ");
// Serial.print(fahrenheitTemp);
// Serial.println(" F");
Serial.print("Humidity: ");
Serial.print(h);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(t);
Serial.println(" *C");
}
delay(500); //Insert a 5sec delay between readings
}
Last modified 5yr ago