DHT11 temperature and humidity on an Arduino Uno

// DHT11: temperature and humidity on one wire, printed every two seconds.
//
//   DHT11 VCC  -> 5V
//   DHT11 DATA -> pin 2
//   DHT11 GND  -> GND
//
// The DHT11 has its own little chip inside. Pull its data line low and it
// answers with forty bits: humidity, temperature and a checksum. The DHT
// library does that handshake; the sketch only asks for the two numbers.
//
// The sensor takes about a second to make a new reading, so asking more often
// than every two seconds just returns the last one again. The DHT11 reads
// whole degrees and whole percent.

#include <DHT.h>

DHT dht(2, DHT11);

void setup() {
  Serial.begin(9600);
  Serial.println("Mokxi Uno: DHT11 temperature and humidity");
  dht.begin();
}

void loop() {
  delay(2000);
  float humidity = dht.readHumidity();
  float celsius = dht.readTemperature();
  if (isnan(humidity) || isnan(celsius)) {
    Serial.println("no reading: check the DATA wire");
    return;
  }
  Serial.print("temperature ");
  Serial.print(celsius, 0);
  Serial.print(" C, humidity ");
  Serial.print(humidity, 0);
  Serial.println(" %");
}