o  Simple LED blinking using Arduino Mega 2560 and Bluetooth module HC-05:

o   Components:

Arduino Mega 2560 (x1)

Bluetooth Module HC-05 (x1)

LED (x3)

10-ohm Resistance (x3)

Jumper Wire (As per Required)

o   Circuit Diagram:

 

o   Connection:

Ø  Take an Arduino Mega 2560/Uno, then take Bluetooth module HC-05.

Ø  Now connect the VCC terminal of the HC-05 to 5V Terminal of Arduino and connect ground (GND) terminal of HC-05 to GND terminal of Arduino.

Ø  Now connect RXD pin of HC-05 to TX0>1 Terminal of Arduino.

Ø  Now connect TXD pin of HC-05 to RX0>0 Terminal of Arduino.

Ø  Here we take pin no 11,12 and 13 of Arduino as a output pin so connect 11,12 and 13 pin with 10 ohm resistance of LED 1, LED 2 and LED 3.

Ø  Now connect this resistance with positive (Long leg) of LED.

Ø  And finally give common ground to all LEDs with GND terminal of Arduino.

o   Program:

Ø  For programming open the Arduino IDE software which is available on Arduino official website.

Ø  Copy the given program and paste it in Software then connect the Arduino with your laptop or pc and upload the program in Arduino.

Ø  Note: To upload the program please remove the Rx and Tx pin from Arduino board. Otherwise it will give error while uploading.

char junk;

String inputString="";

void setup()                    // run once, when the sketch starts

{

 Serial.begin(9600);            // set the baud rate to 9600, same should be of your Serial Monitor

 pinMode(13, OUTPUT);

}

void loop()

{

  if(Serial.available()){

  while(Serial.available())

    {

      char inChar = (char)Serial.read(); //read the input

      inputString += inChar;        //make a string of the characters coming on serial

    }

    Serial.println(inputString);

    while (Serial.available() > 0) 

    { junk = Serial.read() ; }      // clear the serial buffer

    if(inputString == "1"){         //in case of '1' turn the LED 1 on

      digitalWrite(11, HIGH); 

    }else if(inputString == "0"){   //incase of '0' turn the LED 1 off

      digitalWrite(11, LOW);

    }

     if(inputString == "2"){         //in case of '2' turn the LED 2 on

      digitalWrite(12, HIGH); 

    }else if(inputString == "0"){   //incase of '0' turn the LED 2 off

      digitalWrite(12, LOW);

    }

     if(inputString == "3"){         //in case of '3' turn the LED 3 on

      digitalWrite(13, HIGH); 

    }else if(inputString == "0"){   //incase of '0' turn the LED 3 off

      digitalWrite(13, LOW);

    }

    inputString = "";

  }

}

o   Working Demo:

       

You Can see the working Demo on my Youtube channel by searching "CreZy ElecTriCal EnGinEer"
or you can see the video by click the give link.
https://youtu.be/Wh7NqNfDV_g