โมดูลวัดอุณหภูมิและความชื้น DHT22 Digital Temperature and Humidity Sensor

• Accuracy humidity         +-2%RH(Max +-5%RH); temperature +-0.2Celsius
• Resolution or sensitivity humidity 0.1%RH; temperature 0.1Celsius
• Repeatability humidity +-1%RH; temperature +-0.2Celsius
• Humidity hysteresis         +-0.3%RH
• Long-term Stability         +-0.5%RH/year
• Sensing period Average:        2s
• Interchangeability         fully interchangeable
  
  
  

• 3.3-6V Input
• 1-1.5mA measuring current
• 40-50 uA standby current
• Humidity from 0-100% RH
• -40 - 80 degrees C temperature range
• +-2% RH accuracy
• +-0.5 degrees C

/**
   www.arduinoNa.com
   ตัวอย่างโค้ด DHT22 กับ Arduino
*/

//Libraries
#include <DHT.h>;

//Constants
#define DHTPIN 7     // what pin we're connected to
#define DHTTYPE DHT22   // DHT 22  (AM2302)
DHT dht(DHTPIN, DHTTYPE); //// Initialize DHT sensor for normal 16mhz Arduino


//Variables
int chk;
float hum;  //Stores humidity value
float temp; //Stores temperature value

void setup()
{
 Serial.begin(9600);
 dht.begin();
}

void loop()
{
 delay(2000);
 //Read data and store it to variables hum and temp
 hum = dht.readHumidity();
 temp = dht.readTemperature();
 //Print temp and humidity values to serial monitor
 Serial.print("Humidity: ");
 Serial.print(hum);
 Serial.print(" %, Temp: ");
 Serial.print(temp);
 Serial.println(" Celsius");
 delay(10000); //Delay 2 sec.
}



Ref.

https://howtomechatronics.com/tutorials/arduino/dht11-dht22-sensors-temperature-and-humidity-tutorial-using-arduino/