Arduino DHT22取得空氣中濕度及溫度

DHT11與DHT22差異在於DHT22準確度比較高且可取的範圍較廣
另外DHT22別名則是AM2302，不過內部晶片似乎有其不一樣之處，這可能還需各位前輩指教了
我所使用的DHT22Library則是DHT-sensor-library

下圖是我所購買的DHT22

腳位接法如下：

VCC接5V
DATA接Pin 2
NC不接
GND接GND

程式碼：

#include <DHT.h>

#define PIN 2

#define TYPE DHT22

DHT dht(PIN, TYPE);

// the setup function runs once when you press reset or power the board
void setup() {
 Serial.begin(9600);
}

// the loop function runs over and over again until power down or reset
void loop() {
 delay(1000);
 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;
 }

 Serial.print(h, 2);
 Serial.print(",");
 Serial.println(t, 2);
}

執行結果：

參考資料：
https://github.com/adafruit/DHT-sensor-library