Ever wondered how Bluetooth works?

       

  Bluetooth has been always familiar to the common people as a wireless mode of communication technology to send and recieve within short ranges.Bluetooth named after a viking king Harald Bluetooth of Denmark,was concieved at ERRIKSON by Dr. Jaap Haartsen in the mid 1990s and brought up in its end in thought of developing wireless headphones because wired are still annoying.

            

                                   

You can notice the symbol of bluetooth made of letters HB ,after the king.We must know that bluetooth that made our life easy,it has enabled us to now listen songs while travelling connecting it to our car,and even wireless headphones,hand-free calling,mouse and keyboards and even more made available to us.This works a lot like wifi ,in fact allows us to connect devices and transfer data using short wave radio frequencies.

The data transfer principle of bluetooth is by an agreement.Lets take an example,when our mobile phones connects with a bluetooth device we get notified ,to take decision if to pair the device or not.Hence there occurs a small conversation between the two devices to reach to an agreement and proceed.Overtime,this has also become more secure,against security threats setting security questions to grant access and even make undiscoverable ,and remove devices from trusted ones in crowds to prevent BLUEJACKING-sending electronic business cards or adds by company.The amount of non-ionising radiations is much less than that produced by our phones hence the less health concerns.

Bluetooth has a standard of 4.2 core specification and is able to connect almost 8 devices. Its range is about 50 to 150 m with a frequency of about 2.4GHz.The data transfer rate is atmost 1Mbps.Another  application is the bluetooth module  which we can connected us our moblile phone with arduino and make ,because of which it interacts with arduino and arduino is able to read data sent through it and thus allows to control devices using android applications.For example we can build a bluetooth controlled home automation system connecting it with arduino board.

 

 Bluetooth Module         

                   

The bluetooth interfacing with arduino , has to follow certain connections.The bluetooth module HC05 has 6 pins in it which are state,RXD,TXD,GND,VCC,enable.Out of which we do not use the state and enable pins.The TXD and RXD are connected respectively to the TX and RX of the arduino which are digital pins 1 and 0 respectively.The vcc of the module is connected to 5V of the arduino.And GND to ground of arduino.

Let us go through this simple arduino program by which we connect the bluetooth and Arduino UNO to control a led using Arduino Bluetooth Controller app.

                            

     

 Code for the program

So using the app we can controlling the led by switching on and off the device button.This network can be largely applied to build a home automation system.Now a days students also adopt bluetooth module for their experiments and projects .Apart from controlling the led, we can also controll  motors and run small bots for projects.

 So we expect that this might have given you an insight of the bluetooth system and workflow.Keep reading our blogs.