【Arduino Lab】溫濕度感測

【感測器】DHT11

(From Amazon.com)

【配置接線】

【函式庫】DHT, AdaFruit_Sensor

• 請至AdaFruit網站下載 DHT-sensor-library  (DHT11 函式庫), 網頁右側下載。
• 解壓縮後，更變 DHT-sensor-library-master 為DHT, 並置於 Arduino IDE 的 library 目錄下, 例如 : C:\Program Files (x86)\Arduino\libraries\DHT

【程式】

#include "DHT.h"

#define DHTPIN 2     // what digital pin we're connected to

// Uncomment whatever type you're using!

#define DHTTYPE DHT11   // DHT 11

//#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321

//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V

// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1

// to 3.3V instead of 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

// Initialize DHT sensor.

// Note that older versions of this library took an optional third parameter to

// tweak the timings for faster processors.  This parameter is no longer needed

// as the current DHT reading algorithm adjusts itself to work on faster procs.

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");

}

【結果】