TEMPERATURE AND HUMIDITY MEASUREMENT BY DHT11 SENSOR

The following system measures the Temperature and Humidity and gives the data in the two forms, In section 7.2 it will display on the LCD display and In section 7.3 measured data will be sent to the given mobile number.

7.1. Interfacing Temperature and humidity sensor with Arduino

            Vcc pin of DHT11 sensor is connected to 5V pin of Arduino,DATA pin of sensor is connected to A0 of Arduino and Gnd pin of DHT11  is connected to Gnd pin of Arduino.

DHT11 Sensor	Arduino
Vcc	5V
DATA	A0
Gnd	Gnd

7.2. DHT11 sensor with LCD

7.2.1. Circuit diagram:

7.2.2. Arduino program:

#include <dht.h>

#include <LiquidCrystal.h>

#define dht_dpin A0

LiquidCrystal lcd(12, 11, 2, 3, 4, 5);

dht DHT;

void setup(){

  Serial.begin(9600);

  lcd.begin(16,2);

}

void loop(){

  DHT.read11(dht_dpin);

  Serial.print("Current humidity = ");

  Serial.print(DHT.humidity);

  Serial.print("% ");

  Serial.print("temperature = ");

  Serial.print(DHT.temperature);

  Serial.println("C ");

  lcd.clear()

  lcd.print("Humidity: ");

  lcd.setCursor(0,1);

  lcd.print(DHT.humidity);

  lcd.print(" %");

  delay(1000);

  lcd.clear();

  lcd.print("Temperature:");

  lcd.setCursor(0,1);

  lcd.print(DHT.temperature);

  lcd.print(" C");

  delay(1000); 

}

7.2.3. Outputs of the system

7.3. DHT11 sensor with GSM-SIM 900

7.3.1. Circuit Diagram:

7.3.2. Arduino Program:

#include <dht.h>

#define dht_dpin A1

dht DHT;

void setup()

{

                Serial.begin(9600);

           Serial.print(“\r”);

}

void loop()

{

           DHT.read11(dht_dpin);

           Serial.print("AT+CMGF=1\r");

           delay(1000);

           Serial.print("AT+CMGS=\"+919542081456\"\r"); //Number to which you want to send the SMS want to send the SMS

           delay(1000);

           Serial.print("Temperature: ");

           Serial.print(DHT.temperature); //The text of the message to be sent

           Serial.print(" C ");

           Serial.print("Humidity: ");

           Serial.print(DHT.humidity);

           Serial.print(" %");

           delay(1000);

           Serial.write(0x1A);

           delay(1000);

}

Let me know if you have any queries ?