Valentine Idi Bluetooth Technology and Applications Metropolia University of Applied Sciences Bachelor of Engineering Electronics Engineering Bachelor’s Thesis 27 November 2019 Abstract Author Valentine Idi Title Bluetooth Technology and Application Number of Pages 37 pages Date 27 November 2019 Degree Bachelor of Engineering Degree Programme Electronics Engineering Professional Major Electronics Instructors Janne Mäntykoski, Senior Lecturer This thesis concerns about Bluetooth technology; the history, the name, logo and how it all started. This thesis also contains the working principle of Bluetooth and its specifications. There are also different versions of Bluetooth which will be explained in detail in chapter three of this thesis. There are different applications of Bluetooth and just like other wireless technologies, the security issues all of which will be covered in chapter four and five re- spectively. The main objective of this project was to create a heart rate sensor which can be con- nected to a smart phone. This was carried out using nRF51 mbed, a compiler (mbed.org was used in this case), nRF connect software and a Samsung s9+ was used as the smart phone. The code to enable the heart rate sensor of the mbed and to make the mbed dis- coverable via Bluetooth was to be written, complied and with the drag and drop functional- ity of the mbed, dragged in to the mbed disc which was connected to a laptop. The nRF connect software helped to display the simulated heart rate reading. This project will help point out the benefits of Bluetooth for educational purposes as well as personal and Business purposes Keywords Bluetooth, Technology, nRF51, Heart rate sensor Contents 1 Introduction 1 2 Bluetooth 2 2.1 History 2 2.1.1 Bluetooth Technology 2 2.1.2 Bluetooth Name 3 2.1.3 Bluetooth Logo 5 2.2 Working Principle 5 2.2.1 Communication Principle 6 2.2.2 Establishing Connection 8 2.3 Bluetooth Specifications 10 2.3.1 Core Specification 10 2.3.2 Profile Specification 10 3 Bluetooth Versions 10 3.1 Version 1 10 3.2 Version 2 11 3.3 Version 3 12 3.4 Version 4 12 3.5 Version 5 13 3.6 Summary 13 4 Practical Work 14 4.1 nRF51-DK 15 4.2 Features 16 4.3 Details 18 4.4 Experimental Procedure 19 4.4.1 Getting the code ready 19 4.4.2 Connecting nRF51-DK to our pc/laptop 20 4.5 Analysis 23 5 Applications of Bluetooth 25 5.1 Transfer of files 26 5.2 Home Security/Smart Home Control 26 5.3 Connecting Different Devices 27 5.4 Bluetooth Tethering 28 6 Bluetooth Security, Advantages/Limitations Of Bluetooth 29 6.1 Bluetooth Security 29 6.1.1 Bluetooth security modes 29 6.1.2 Bluetooth security issues 31 6.2 Advantages of Bluetooth 31 6.3 Disadvantages of Bluetooth 32 7 Summary 33 References 35 List of Abbreviations AES-CMAC Advanced encryption standard-Cipher based message authentication code ANT Adaptive network topology ARM Advanced RISC machine CMSIS-DAP Cortex Microcontroller software interface standard-debug access port CTO Chief technology officer ECDHE Elliptic curve Diffe-Hellman EDR Enhanced Data Rate eSCO Extended synchronous connections Etc etcetera GCC GNU compiler collection GHz Gigahertz HCI Host controller interface HS High speed IAR Ingenjörsfirman Anders Rundgren(Anders Rundgren Engineering Com- pany) IDE integrated development environment IEEE institute of electrical and electronics engineers I/O input/output Kbps Kilobits per second L2CAP Logical link control and adaptation protocol LED Light emitting diode Mb/s Megabit per second Mbit/s Megabit per second Ps4 Playstation 4 RF Radio frequency SIG Service integration gateway SoC System on Chip USB Universal serial Bus Tv Television WiFi Wireless Fidelity 1 1 Introduction Bluetooth technology is arguably one of the most popular technologies in the world. Blue- tooth was discovered back in 1995 when Haartsen managed to develop the technology with his partner Sven Mattison. Bluetooth has gotten huge improvements down the years and the popular technology became even more popular and more useful. There are nu- merous things that can be done with this technology such as home security, transfer of information or files, communicating two devices etc. This thesis will cover the history of Bluetooth; how the name and logo came to be and who invented the technology in the first place. Although we use Bluetooth everyday of our lives, most people do not know how it works and this thesis will cover that as well. Although the current version of Bluetooth which was released in January 2019 is version 5.0, there has been other versions of Bluetooth such as version 1.0, 1.1b, 2.0 etc and these versions had their issues which were fixed in the next version. This thesis concerns everything about the versions, the issues and how they were fixed in the next version. Along the years, a lot of people are still confused on how good or bad Bluetooth security is; if it can be accessed easily or if it has any security issues at all. There is no wireless system without any security issues and just like WiFi, infrared and other wireless sys- tems, Bluetooth is no exception to security problems. There has been a lot of methods used such as Bluebugging, bluesnarfing etc. All these security issues will be explained in detail in chapter five of this thesis. The purpose of this thesis was to create a heart rate sensor with an nRF51-DK mbed development kit and with the help of a smartphone and nRF connect app, get the reading from the sensor and display on the smartphone. This will be discussed in details in chap- ter 4 of this thesis 2 2 Bluetooth 2.1 History Bluetooth is a technology that is persistent in our daily lives. It exists in wide range of our devices: in speakers, wireless headphones, our mobile phones etc. Bluetooth is one of those technologies that the world cannot do without because it is so handy and makes every connection easy and convenient. It is used in speaker connection to tv, Bluetooth wifi tethering, ps4 controllers, occasional file transfer from mobile device to laptop. Alt- hough this technology is very useful to most if not everybody, it is a surprise that most people do not know how it came about. 2.1.1 Bluetooth Technology In 1993, Jaap Haartsen a wireless communications engineer who worked at Ericsson was given the task to develop a short-range connection for mobile phones because back then, wires/cables were hindering communication systems. [2] Figure 1. Jaap Haartsen [1] In 1995 Haartsen (who can be seen in figure 1) was able to develop a technology called multi-communicator links with the help of his engineer partner, Sven Mattison. Although 3 it was those two that are always being credited for creating Bluetooth, it was Ericsson’s CTO that came up with the idea and initiated the development four years before Haartsen was appointed for the task.[2] There were also some other people that made the creation of Bluetooth possible and each of those people contributed to the completion of the pro- ject.[2] 2.1.2 Bluetooth Name To be a successful company, you need to have a good brand name. Just like Apple, Samsung, Nike, etc Bluetooth was a well thought brand name. Bluetooth is arguably a name that does not sound technological and that makes it unique from other brand names. The name Bluetooth originated from the 10th century from the Danish king, Herald who can be seen from figure 2 below. It is still a debate why the king had the nickname. Some people say that he liked to eat blueberries while some others say it is because he had a ‘dead/blue’ tooth. Now, the confusion is, why did a technology company decide to choose their brand name from a king who existed back in the 10th century. 4 Figure 2. King Herald [3] The brand name was given in the summer of 1997 when Sven Mattisson of Ericsson met with Jim Kardach of Intel in a local pub. They talked about history and Mattisson brought up a book called “The Longships” where he had learned about the King of Denmark, King Herald. Kardach went home after the meeting and researched more about King Herald and how he united several parts of Scandinavia together and building connections between separated groups. This makes sense as Bluetooth is all about connecting to devices. 5 2.1.3 Bluetooth Logo As the name, the Bluetooth logo also came from Danish King Herald Bluetooth. The Bluetooth logo is the combination of the letter ‘H’ and the ‘B’ which are written in ancient letters that were used by the Vikings called runes. The letters can be seen in figure 3 below. Figure 3. Bluetooth logo [4] 2.2 Working Principle Like every other wireless communication as can be seen in figure 4 below, Bluetooth works by sending and receiving data in the form of radio waves by the help of a card-like attachment known as Bluetooth adapter in the Bluetooth enabled device. The Bluetooth adapter has the function of sending and receiving data and has a range of connection. The Bluetooth adapter is to be in range for the other adapter to communicate with it. 6 When they are in range, they can now communicate with each other in a process known as pairing. Figure 4. Bluetooth adapter [5] 2.2.1 Communication Principle As mentioned already above, Bluetooth uses radio waves to send data. When two de- vices are looking for each other to be paired, they are searching for a common frequency through which they can send and receive data.