Introduction: Arduino AND Bluetooth HC-05 Connecting Easily

By Mohannad Rawashdeh
About: Maker, PCB designer , electronics instructor from Jordan just one word ! I Adore electronics follow me on FB https://www.facebook.com/Mohannad-Rawashdeh-Raw-774983565988641/


Hello Every body , This is my first artical on Instructable.com , I'm so happy for that , and I will start by How to connect arduino with bluetooth , I suffered a lot of problems when I try to connect it as the website and instructable artical did , So i decided To share my experience with You

The bluetooth module I will use today is HC-05 which is so familiar and cheap ,

Most tutorial on The website Connect the bluetooth with default Rx and Tx on the arduino Board , I faced a lot of problem and bluetooth didn't work will .

But arduino  support something Called Software Serial , which allow You to change any arduino board pin to serial pin 

http://arduino.cc/en/Reference/SoftwareSerial

so After reading this article you will be able to:

1) Connect arduino Board with PC By Bluetooth , to send and receive data .
2)Connect arduino Board with Any android device .

so you can send your information , Like Sensors reading , from arduino to PC Or android device , and you can build your Home automation system by bluetooth , and controlling your robot wirelessly


Step 1: Material and Connection

you need to do this experiment :

1) Arduino Board " I used Arduino Uno ".
2) Bluetooth module HC-05.
3)Solderless jumper.
4)Bread Board .
5)Battery 9V "Optional".

The connction between  Arduino and bluetooth is like the schematic above 





Step 2: Connect Arduino With PC

We now want to send or receive Data between arduino and computer , first we need to make a Communication link to Definition arduino Board to the computer .

We will need a software called Tera Term to show the data received or what we want to send through it .

You can download Tera Term or any terminal emulator software , you can download Tera term  from this link :

http://hp.vector.co.jp/authors/VA002416/ttermv14.zip

To make a link between your Arduino and bluetooth , do the following :

1) Go to the  bluetooth icon , right click and select Add a Device 

2) Search for new device , Our bluetooth module will appear as HC-05 , and add it 

3) The pairing code will be 1234 .

4)after make a pairing , we can now program the arduino and upload a sketch  to send or receive data from Computer.

Step 3: Arduino Code

As I mentioned before , I will use software serial library to make pin D10 & D11 As Tx & Rx instead of using the default Rx and tx " D0 &D1 On most arduino Board " .

this program below allow us to control LED connected to D13 To blink on/off , by press # 1 from PC Keyboard the LED blink on , and if we press 0 LED blink off ! 

To send the Control commands from Computer to arduino , Go to the tera term , Run it , and choose Serial , and select the bluetooth Serial from the list as Shown on the picture .

The code below :

// This program shown how to control arduino from PC Via Bluetooth
// Connect ...
// arduino>>bluetooth
// D11   >>>  Rx
// D10   >>>  Tx
//Written By Mohannad Rawashdeh
//for http://www.genotronex.com/

// you will need arduino 1.0.1 or higher to run this sketch

#include <SoftwareSerial.h>// import the serial library

SoftwareSerial Genotronex(10, 11); // RX, TX
int ledpin=13; // led on D13 will show blink on / off
int BluetoothData; // the data given from Computer

void setup() {
  // put your setup code here, to run once:
  Genotronex.begin(9600);
  Genotronex.println("Bluetooth On please press 1 or 0 blink LED ..");
  pinMode(ledpin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
   if (Genotronex.available()){
BluetoothData=Genotronex.read();
   if(BluetoothData=='1'){   // if number 1 pressed ....
   digitalWrite(ledpin,1);
   Genotronex.println("LED  On D13 ON ! ");
   }
  if (BluetoothData=='0'){// if number 0 pressed ....
  digitalWrite(ledpin,0);
   Genotronex.println("LED  On D13 Off ! ");
  }
}
delay(100);// prepare for next data ...
}

After uploading This sketch go to tera term and press 0 or 1 and see the results

This Video show the results of this code .

Step 4: Connect Arduino to Android Device

after we finished from connecting arduino with PC By bluetooth , let's move to how we can connect arduino To android device .

at first you need a terminal emulator on your andriod device to send or receive  data to arduino .

You can download this app from Google play .

https://play.google.com/store/apps/details?id=arduino.bluetooth.terminal&feature=search_result#?t=W251bGwsMSwxLDEsImFyZHVpbm8uYmx1ZXRvb3RoLnRlcm1pbmFsIl0.

after that , you can use the same arduino Sketch and control LED Blinking on or Off from android device .

just  type and t send #1 to make LED Blink on , or 0 to blink off .

this video below show how to control arduino I/O from android tablet .



Step 5: Receiving Data From Arduino

The last arduino Sketch that i wrote , used to send commands from PC Or android device  to android , Now in this program i will use arduino to Calculate the time since the start of the program in second , and send it Via bluetooth to any pairing device .

the code below 

// This program shown how to control arduino from PC Via Bluetooth
// Connect ...
// arduino>>bluetooth
// D11   >>>  Rx
// D10   >>>  Tx
//Written By Mohannad Rawashdeh
//for http://www.genotronex.com/

// you will need arduino 1.0.1 or higher to run this sketch

#include <SoftwareSerial.h>// import the serial library

SoftwareSerial Genotronex(10, 11); // RX, TX
int ledpin=13; // led on D13 will show blink on / off
long previousMillis = 0;        // will store last time LED was updated

// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long interval = 1000;           // interval at which to blink (milliseconds)
int ledState = LOW;             // ledState used to set the LED
long Counter=0; // counter will increase every 1 second
void setup() {
  // put your setup code here, to run once:
  Genotronex.begin(9600);
  Genotronex.println("Bluetooth On please wait....");
  pinMode(ledpin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis > interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;  
     Counter+=1;

    Genotronex.println(Counter);

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW)
      ledState = HIGH;
    else
      ledState = LOW;

    // set the LED with the ledState of the variable:
    digitalWrite(ledpin, ledState);
  }
}

at the end , You can visit the orginal artical in arabic language on my website

http://www.genotronex.com/

Hope my first artical here is useful to you  , thank you for your time ,