Arduino 教程Arduino 濕傳感器

1、第三十五課 Arduino 濕度傳感器在本節(jié)中，我們將學(xué)習(xí)如何使用不同的傳感器連接我們的Arduino板。我們將討論以下傳感器：· 濕度傳感器（DHT22）· 溫度傳感器（LM35）· 水位檢測(cè)傳感器（簡(jiǎn)單水觸發(fā)器）· PIR傳感器· 超聲波傳感器· GPS濕度傳感器(DHT22)DHT-22（也稱(chēng)為AM2302）是一個(gè)數(shù)字輸出，相對(duì)濕度和溫度傳感器。它使用電容式濕度傳感器和熱敏電阻來(lái)測(cè)量周?chē)諝?，并在?shù)據(jù)引腳上發(fā)送數(shù)字信號(hào)。在本例中，你將學(xué)習(xí)如何將此傳感器與Arduino UNO一起使用。室溫和濕度將打印到串口監(jiān)視器上。DHT-22

2、傳感器連接很簡(jiǎn)單。左邊的第一個(gè)引腳為3-5V電源，第二個(gè)引腳連接到數(shù)據(jù)輸入引腳，最右邊的引腳接地。技術(shù)細(xì)節(jié)· 電源 - 3-5V· 最大電流 - 2.5mA· 濕度 - 0-100，精確度為2-5· 溫度 - 40至80°C，精確度為±0.5°C必需的組件你將需要以下組件：· 1 × Breadboard 面包板· 1 × Arduino Uno R3· 1 × DHT22· 1 × 10K歐姆電阻程序按照

3、電路圖連接面包板上的組件，如下圖所示。草圖在計(jì)算機(jī)上打開(kāi)Arduino IDE軟件。使用Arduino語(yǔ)言進(jìn)行編碼控制你的電路。通過(guò)單擊“New”打開(kāi)一個(gè)新的草圖文件。Arduino代碼/ Example testing sketch for various DHT humidity/temperature sensors#include "DHT.h"#define DHTPIN 2 / what digital pin we're connected to/ Uncomment whatever type you're using!/#define DH

4、TTYPE 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 you

5、r 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

6、 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() delay(2000); / Wait a few seconds between measurements float h = dht.readHumidity(

7、); / Reading temperature or humidity takes about 250 milliseconds! float t = dht.readTemperature(); / Read temperature as Celsius (the default) float f = dht.readTemperature(true); / Read temperature as Fahrenheit (isFahrenheit = true) / Check if any reads failed and exit early (to try again). if (i

8、snan(h) | isnan(t) | isnan(f) Serial.println("Failed to read from DHT sensor!"); return; / Compute heat index in Fahrenheit (the default) float hif = puteHeatIndex(f, h); / Compute heat index in Celsius (isFahreheit = false) float hic = puteHeatIndex(t, h, false); Serial.print ("Humid

9、ity: "); Serial.print (h); Serial.print (" %t"); Serial.print ("Temperature: "); Serial.print (t); Serial.print (" *C "); Serial.print (f); Serial.print (" *Ft"); Serial.print ("Heat index: "); Serial.print (hic); Serial.print (" *C "); Serial.print (hif); Serial.println (" *F");代碼說(shuō)明DHT22傳感器具有四個(gè)端子連接到電路板的端子（Vcc，DATA，NC，GND），如下：· DATA引腳連接到Arduino的2號(hào)引腳號(hào)· Vcc引腳