Procedure with Output

Steps to connect the components :

• Connect pin 1 (on the left) of the DHT11 sensor to +5V

• Connect pin 2 of the DHT11 Sensor to pin 12 of Arduino Uno.

• Connect pin 3 of DHT11 to the ground.

• Now, connect pin 1 of the Soil Moisture Sensor to +5V.

• Connect pin 2 of the Soil Moisture sensor to the ground.

• And pin3 of the Soil Moisture sensor is not connected.

• Connect pin 4 (on the left) of the sensor to pin A0 of the Arduino Uno.

• In LDR Sensor, connect a 10K resistor from pin 2 to the ground and pin 2 also with pin A1 of Arduino Uno

• Finally, connect pin 1 (power) of the LDR sensor to 3.3V of Arduino Uno.

• In Bluetooth Module, connect Vcc and Gnd to +5V and Gnd of Arduino Uno. Tx and Rx to pin 7 and pin 8 of the Arduino pin respectively.

Program :

• Open Arduino IDE.

• Paste the following program.

#include <SoftwareSerial.h> 
#include "DHT.h"
#include <Wire.h> 
 
#define DHTPIN 12     // what pin we're connected to
 
//Uncomment whatever the type of sensor we are using. 
#define DHTTYPE DHT11   // DHT 11 
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

int sensorPin = A0;
int sensorValue = 0;
int percentValue = 0;
const int ldrPin = A1;
 
// Initialize DHT sensor for normal 16mhz Arduino
DHT dht(DHTPIN, DHTTYPE);
 
char inchar; // Will hold the incoming character from the GSM shield

int bluetoothTx = 7; // bluetooth tx to 7 pin
int bluetoothRx = 8; // bluetooth rx to 8 pin
 
SoftwareSerial blue( bluetoothTx, bluetoothRx); // bluetooth module will be connected here.
//int bluetoothTx = 7; // bluetooth tx to 7 pin
//int bluetoothRx = 8; // bluetooth rx to 8 pin

//SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

int powerb = 6; // to power up the dht11 sensor, dht11 5v wire is connected with pin6 of the arduino. 
 
String TextForSms ;
String TextForSms2 ;
String TextForSms3 ;
String humidity = " Humidity: %";
String temperature = "   Temperature";
String sign = " *C";

void setup() {
 
  Serial.begin(9600);
  blue.begin(9600); // original 19200
  pinMode(powerb, OUTPUT); 
  digitalWrite(powerb, HIGH); 
   dht.begin();
  //Setup usb serial connection to computer

  Wire.begin();
  pinMode(ldrPin, INPUT);
}
 
 
void loop() {
 
if(blue.available() == 0);
 
  if(blue.available() >0)
  {
    inchar=blue.read(); 
  Serial.println(inchar);
    delay(20);
    if (inchar=='x')
    {
      delay(10);
 
   Serial.println(inchar);
    
  // 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)
  int h = dht.readHumidity();
  // Read temperature as Celsius
  int t = dht.readTemperature();
  // Read temperature as Fahrenheit
  int 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;
  }

    sensorValue = analogRead(sensorPin);
    Serial.print("\n\nAnalogValue:");
    Serial.print(sensorValue);
  
    percentValue = map(sensorValue, 1023, 200, 0, 100);
    
    Serial.print("\nPercentValue: ");
    Serial.print(percentValue);
    Serial.print("%");
    
    Serial.print("Soil Moisture");
    Serial.print("Percent: ");
    Serial.print(percentValue);
    Serial.print("% \n\n\n");
    delay(5000);

  sensorValue = analogRead(sensorPin);
  Serial.print(sensorValue);
 
  // Compute heat index
  // Must send in temp in Fahrenheit!
  int hi = dht.computeHeatIndex(f, h);
 
  Serial.print("Humidity: "); 
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: "); 
  Serial.print(t);
  Serial.print(" *C ");

  
  int ldrStatus = analogRead(ldrPin);
  Serial.print(ldrStatus);
    delay(1000);
  
  TextForSms = TextForSms + "AIR HUMIDITY: ";
  TextForSms.concat(h);
  TextForSms = TextForSms + "% AIR TEMPERATURE: ";
  TextForSms.concat(t);
  TextForSms = TextForSms + "*C";
  blue.print(TextForSms);
  Serial.println(TextForSms);
  delay(2000);
  TextForSms = " ";

  TextForSms2 = TextForSms2 + "    SOIL HUMIDITY: ";
  TextForSms2.concat(percentValue) + "%";
  blue.print(TextForSms2 + "%");
  Serial.println(TextForSms2 + "%");
  delay(2000);
  TextForSms2 = " ";

if (ldrStatus > 400) {
  TextForSms3 = TextForSms3 + "  LUMINOSITY: ";
  TextForSms3.concat(ldrStatus);
  TextForSms3 = TextForSms3 + " (Good light)\n";
  blue.print(TextForSms3);
  Serial.println(TextForSms3);
  delay(2000);
  TextForSms3 = " ";
}
else if (ldrStatus > 150 && ldrStatus < 500) {
  TextForSms3 = TextForSms3 + "  LUMINOSITY: ";
  TextForSms3.concat(ldrStatus);
  TextForSms3 = TextForSms3 + " (Medium light)\n";
  blue.print(TextForSms3);
  Serial.println(TextForSms3);
  delay(2000);
  TextForSms3 = " ";
}
else {
  TextForSms3 = TextForSms3 + "  LUMINOSITY: ";
  TextForSms3.concat(ldrStatus);
  TextForSms3 = TextForSms3 + " (Bad light)\n";
  blue.print(TextForSms3);
  Serial.println(TextForSms3);
  delay(2000);
  TextForSms3 = " ";
}
    }
  }