Bluetooth Based Household Automation By Michael Johnson Department of Computer Science Submitted in partial fulfillment of the requirements for the degree of Bachelor of Computer Science Algoma University College Sault Ste. Marie, Ontario April 2008 © Michael Johnson 2008 :, e of Cot trl Chapter 1 Introduction 1 1.1 Brief Overview of Bluetooth Technology 1 1.2 Project Plan 2 1.3 Contribution 3 Chapter 2 Internet and Other Wireless Internet Technologies 4 2.1 History of Wireless Communication and its Implementation 4 2.2 Types of Wireless Communications 5 2.2.1 Radio Transmission 5 2.2.2 Microwave Transmission 6 2.2.3 Infrared Transmission 6 2.3 PANs 7 2.3.1 PAN Connections 7 2.3.2 PAN Networking 8 2.4 Internet Applications 9 Chapter 3 Bluetooth 11 3.1 History 11 3.2 Bluetooth SIG 12 3.3 Aim of Bluetooth 13 3.4 How Bluetooth Works 13 3.5 Applications of Bluetooth 15 3.6 Bluetooth Protocol Stack 17 3.6.1 Radio 18 3.6.2 Baseband 18 3.6.3 Link Manager 21 3.6.4 Host Controller Interface 22 3.6.5 Logical Link Control and Adaptation Protocol (L2CAP) 24 3.6.6 RFCOMM 26 3.6.7 Service Discovery Protocol 28 3.6.8 The Wireless Application Protocol (WAP) 30 3.6.9 OBEX 32 3.6.10 Telephony Control Protocol Specification (TCS) 33 Chapter 4 Architecture of Household Automation 35 4.1 Roomba Vacuum 35 4.1.1 Roomba History 35 4.1.2 Parts of the Roomba Vacuum 36 4.1.3 The Cleaning Algorithm 37 4.2 Power Regulating Circuit 38 4.3 Online Availability 40 Chapter 5 Implementation and Experimental Results 42 5.1 Issues related to sending commands through Bluetooth 42 5.2 General Overview of Project 43 5.2.1 Client-side Application 44 5.2.2 Server-side Application 45 5.2.3 Roomba vacuum 47 ii Chapter 6 Chapter Summary and Future Directions 48 6.1 Chptr Sr 48 6.2 tr rtn 9 Bibliography Errr r nt dfnd Glossary 51 111 Table of Figures Figure 2.1 The Seven Layers of the OSI Model 8 Figure 3.1 Bluetooth Protocol Stack 17 Figure 3.2 THE WAP Protocol Stack 31 Figure 4.1 Power Regulating Circuit 38 Figure 5.1 Client-Side Application Screenshot 44 Figure 5.2 Server-Side Application Screenshot 46 iv Chpt: Intrdtn 1.1 Brief Overview of Bluetooth Technology 1.2 Project Plan 1.3 Contribution . rf Ovrv f ltth hnl Bluetooth technology is a newer technology which allows for short range wireless communication. The range Bluetooth technology can handle depends on the devices being used however it is generally between 10 and 100 meters. The technology allows for multiple devices to communicate with each other. Currently, the most common use for Bluetooth technology is the wireless headset for cellular phones or Personal Digital Assistants. Many companies are trying to determine new and different ways to exploit this technology for its products. Those companies see a value that Bluetooth brings to the industry of wireless communication. A lot of these companies which are rivals in certain aspects are actually helping each other out to develop new ways to use Bluetooth. They understand that they may be helping their competitors but they also see more revenue they can generate from this technology. 1 ,2 rjt ln In th I plntd ltth bd t hh ll r t ntrl b v h t prt th r t vt pf bt fr hh th n lt nd tht n b prfrd b thr b v On nd ltd t ll b nt fr th bt t th b v ltd n thr h h ll th r t plt h vn fr nhr hh h t th Intrnt hh lt vrhr nd Whn th t rv th nd hn b th r t ltth nntn th th b v tlf t p th nd t th v h t nd th b v ll bvl nd t t thn th ltth ntn rn thrfr th t ll l nd t b ltd n th r h hr n rl rn t b v thr thn th ft tht t n rv r thn pl n r ff nd h rn th nd "ltth d hld Attn" b n hhld ppln ld hv bn d hrfr t nt ltd t th f b v 2 . 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The earliest works of wireless technologies are that of telegraphy which would receive Morse code through an apparatus. Once the data being sent over and the methods to send it were becoming much more complex, these were adapted to the wireless world and new and great ideas were implemented. The first major use of wireless technology was for the use of broadcast radio. The next one would be that of cellular phones which would provide the user with mobility while maintaining the same uses provided by standard telephones. Lastly and more recently, the use of wireless technology to connect to the Internet has been implemented, this ties in with my study on Bluetooth as it will wirelessly communicate with any Bluetooth enabled device and will then be able to send over any data needed. The usefulness of wireless technology will always exist because it will always be seen as an improvement from the norm as it provides the flexibility an end-user would want. 4 2.2 p f Wrl Cntn These wireless signals being transmitted can be sent in many different ways. The three most common ones are radio, microwave and infrared [7]. Bluetooth technology uses the 2.4GHz radio frequency band to transmit data. Not only can the frequencies change, but the way the wireless signal is sent can change to, and that obviously directly ties into the use of wireless for the application. The signal can be sent point-to-point which is as it implies, from a single point to another, similar to cellular phone communications. The signal can be sent point-to-multipoint which simply means that the signal will originate from a single location, however the signal will be dispersed to a multitude of locations such as VOIP(Voice over Internet Protocol) or general wireless Internet communications. The signal can be sent through a broadcast which is used by radio and will send its signal out to an intended audience and as is the case with most forms of broadcasting, the user needs to be set to the specific location where the broadcast is being sent to whether it is a television channel or a radio station. 2.2. d rnn Radio transmissions are done by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing some property of the radiated waves such as their amplitude or their frequency. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor which is detected and transformed into sound or other signals that carry information. 5 2.2.2 Mrv rnn Microwaves are electromagnetic waves with wavelengths shorter than one meter and longer than one millimeter or frequencies between 300 megahertz and 300 gigahertz. Electromagnetic waves with a lower frequency are radio waves. Bluetooth and wireless technology uses microwaves in the 2.4 GHz ISM band. Cable television and Internet access on coaxial cable as well as broadcast television use some of the lower microwave frequencies. 2.2. Infrrd rnn Infrared is an electromagnetic radiation of a wavelength longer than that of visible light but shorter than that of microwaves. The name means below red because red is the color of visible light with the longest wavelength Infrared transmission is used for many different reasons such as infrared filters, night vision, tracking, heating and communication. Remote controls are a popular infrared communication device. The device uses an infrared LED to emit infrared radiation which is focused by a plastic lens into a narrow beam.