To determine the humidity using Arduino

Aim

To determine the humidity using Arduino

Tools and Components required:

1. Arduino UNO board
2. DHT-22
3. Bread Board
4. Arduino Software.
5. Connecting Wires

Theory

The DHT-22 (also named as AM2302) is a digital-output, relative humidity, and temperature sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and sends a digital signal on the data pin.

Circuit Diagram:

Program:

#include "DHT.h"

#define DHTPIN 2

#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

void setup() {

Serial.begin(9600);

Serial.println("DHTxx test!");

dht.begin();

}

void loop() {

delay(2000);

float h = dht.readHumidity();

float t = dht.readTemperature();

float f = dht.readTemperature(true);

if (isnan(h) || isnan(t) || isnan(f)) {

Serial.println("Failed to read from DHT sensor!");

return;

}

float hif = dht.computeHeatIndex(f, h);

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");

}

Result:The obstacle are detected using an ultrasonic sensor and arduino UNO.