Abstract—Smart grids are an evolution of the existing electric distribution systems due to the growing demand of energy, the expansion in the use of renewable energy sources, and the development of novel and innovative information and communication technologies (ICT). The installation of systems based on wireless networks can play a key role in the extension of the smart grid toward smart homes, that can be deemed as one of the most important components of smart grids. In fact, monitoring and control applications, energy harvesting, and innovative metering methodologies through smart wireless devices are becoming increasingly important. This paper proposes a novel energy management approach for smart homes that combines a wireless network, based on bluetooth low energy (BLE), for communication among home appliances, with a home energy management (HEM) scheme. The proposed approach addresses the impact of standby appliances and high-power rating loads in peak hours to the energy consumption charges of consumers. Simulation results show that the proposed approach is efficient in terms of reducing peak load demand and electricity consumption charges with an increase in the comfort level of consumers.

INTRODUCTION

GREEN Communications can be defined as a framework for the design and the disposal of communication networks which aims to a sustainable growth of telecommunications networks including wired and wireless networks. In fact, in recent years, the energy optimization is attracting an increasing interest among researchers as long as new “smarter” infrastructures and devices are going to replace the traditional ones. Moreover, the attention has also focused on renewable energy sources due to the growing concern on environmental impacts of conventional energy sources and the finite life of fossil-based fuels. Considering that, currently, about 3% of the world-wide energy is consumed by the Information and Communication Technologies (ICT) infrastructures, which causes about 2% of the world-wide C O2 emissions, several research efforts have been made in order to address and overcome this problem. These studies have led to the smart grid concept in order to facilitate the cost-effective exploitation of the present renewable energy potential and to provide the required flexibility to the electricity grid with the help of Information and Communication Technologies.
The smart grids are an evolution of the existing electric distribution systems due to the growing demand of energy [1], [2], the expansion in the use of renewable energy sources [3], [4] and the developments of novel and innovative ICT-based approaches [5], [6]. They are an efficient solution both from the energy and especially from the economic points of view.
The term “smart grid” [7] refers to an electricity transmission and distribution system that incorporates elements of traditional and cutting-edge power engineering, sophisticated sensing and monitoring technology, information technology, and communications to provide better grid performance and to support a wide array of additional services to consumers, such as energy efficiency, power quality and system reliability, obtained by using multiple tools of smart grid such as advanced meters [8], two-way communications [9] and intelligent control equipment [10]. From the studies and results shown in these works (from [1] to [10]) it is clear that smart grids can play also a concrete role in reducing the emissions of greenhouse gases, such as nitrous oxide, methane and carbon dioxide.
Applications of smart grid include several areas, such as transmission and distribution automation, optimized utilization, commodity trading of electricity in competitive markets, etc., and their structures, components and advantages have been deep analyzed in the literature. In [11], [12] it is highlighted that the power flow in grids can be carried out more efficiently by obtaining and then evaluating the consumption profiles of houses. This has led other researchers [13], [14] to focus on “smart homes” that can be deemed as one of the most important components of smart grids. A smart home is a residential dwelling equipped with sensors and possibly actuators to collect data and send controls according to occupants’ activities and expectations. However, an important role is also played by consumers because, as shown in [15], the reduction of energy consumption can be obtained by only providing the consumption profile of appliances to the consumers and accordingly helping them to change their behavior. This approach, known as Demand Side Management (DSM), based on bi-directional communication is enabled by smart grid in order to smooth the load curve of the traditional grid. DSM programs influence the behavior of the consumers regarding electricity consumption. In fact, DSM technique mainly relies on matching present generation values with demand by controlling the energy consumption of appliances and optimizing their operation at the user side. A practical usage can be the shifting of “wet appliances”, such as washing machines and dishwashers, from peak time to off-peak time. For instance, as shown in [16], [17], through the energy usage optimization in smart houses it is possible to obtain an average electricity consumption saving of about 30%.
Other approaches are based on Time-of-Use (TOU) pricing, where electricity prices are set for a specific time period on an advance or forward basis. Prices paid for energy consumed during these periods are predetermined and known to consumers in advance, allowing them to vary their usage in response to such prices and manage their energy costs by shifting usage to a lower cost period or reducing their consumption overall. As shown in [18] a TOU tariff implies a higher electricity demand and lower price values rather than a flat one, while in [19] an optimal energy management controller of a smart home in case of DSM and TOU tariff is introduced and reasonable results are obtained in terms of economic savings. Moreover, in the approach proposed in [20] a day is divided in consecutive time slots of equal lengths with varying prices of electricity consumption in order to minimize the cost of electricity consumption at home. In fact, the inputs of the proposed model are consumer’s requests and the model returns the optimum appliance scheduling at the output in order to reduce home energy expenses. The TOU tariff system is used in order to provide a more equal energy consumption distribution. In fact, there are
certain ranges of hours having different electricity prices in the day and end-users pay depending on the time of the day when they use the electricity service. However, the reduction of the bills payed by users without deteriorating the comfort level in the home can be relatively difficult.
Wireless Sensor Networks (WSNs) are getting more integrated to our daily lives and smart surroundings as they are being used for health, comfort and safety applications. In smart homes and office environments, WSNs are generally used to increase the inhabitant comfort. As the current energy grid is evolving into a smart grid, where consumers can directly reach and control their consumption, WSNs can take part in domestic energy management systems, as well. For these reasons, in the literature other approaches based on WSNs for smart grids and smart homes have been proposed [21], [22]. In fact, advanced ICTs, monitoring and control, energy harvesting [23] and innovative metering technologies via smart wireless devices, are becoming increasingly important. For instance, in [24] a domestic energy management scheme based on a Wireless Sensor Home Area Network (WSHAN) is introduced.
This scheme focus on the communication among smart appliances and an Energy Management Unit (EMU) through the wireless network and consumer demands are processed in near real-time. On the contrary, the approaches proposed in [25], [26] aim at TOU pricing benefit in order to decrease the energy cost. The goal of the authors is to shift the consumer load to off-peak periods using the WSN for delivery their requests to the EMU. However, although the analyzed WSN-based works (from [21] to [26]) obtain good performance, their authors do not bother to choose the most appropriate wireless protocol. In fact, the choice of a wireless protocol with respect to another one may involve significant benefits and quite different results.
To cope with the Home Energy Management (HEM) which can be optimized in smart grid environments, in this paper a novel energy management approach, called BluHEMS

Fig. 1. The proposed energy management system for smart homes.

(Bluetooth Home Energy Management Scheme), is introduced. The proposed approach is based on the communication among home appliances, a central EMU, a smart meter and a storage unit inside a smart home. In fact, the analyzed literature works have clearly shown that a HEM implementation can lead to socially and economically beneficial environment by addressing consumers’ and utilities concerns. For instance, increased savings, better peak load management and the reduction in peak to average ratio are some of the benefits that can be achieved by the approach proposed in this paper. The communication among the different entities involved in BluHEMS is based on a WSHAN using the Bluetooth Low Energy (BLE) protocol [27]. The novelty introduced in this work is both the use of a HEM scheme that take into account the consumer’s feedback and mainly the use of BLE in the wireless network that coordinates the communication between home appliances in BluHEMS. The benefits of BluHEMS are confirmed by validations, whereas, to the best of our knowledge, there are no works in the literature in which BLE is applied in a wireless network that supports a HEM scheme.
This paper is organized as follows. Section II presents the proposed smart home system, introducing both the home energy management scheme and the WSHAN. Section III presents the proposed home energy management algorithm while Section IV shows simulation results. Finally, Section V concludes the paper and outlines some hints for future work.

II. THE PROPOSED SMART HOME SYSTEM

Before introducing the proposed home energy management algorithm, the concept of the proposed smart home system is presented. As shown in Figure 1, the proposed system consists of various energy sources, storage devices, electrical appliances, a control unit and related communication tools. The home is able to generate its own energy thanks to renewable energy sources, such as wind turbine and solar photovoltaic panels, and stores this energy by the means of batteries.
Moreover, a “charging station”, a kind of inverter, converts direct current electricity from renewable energy sources or a home battery into the alternating current used by home’s lights, appliances and devices. Anyhow, it is obvious that even the energy from high voltage power line can be used. However, it is useful to highlight that in homes the high voltage is not used. For this reason, transformer stations, outside of the housing, are used for the transformation from high to low voltage.
It is necessary to note that the renewable power forecasting methodology is not addressed in this paper because it is not the main aim of this work. However, it is useful to briefly introduce some features that must be taken into account in the selection and development phases of renewable energy sources. For instance, regarding to the wind turbines, features like the high efficiency at low wind speeds and the capabilities of communication and remote monitoring have to be considered. Likewise, the power ratings of solar photovoltaic panels and the power converter circuit required to DC-AC power conversion must be chosen in a similar way and the best angle for panels has to be calculated after facing the panels south in order to exploit solar energy potential.
Several electrical appliances are part of the smart home system. They are used at various time periods in every day depending mainly on the day of the week. In fact, there are substantial differences in the usage time of appliances throughout the day, especially between working days and weekend. For instance, a refrigerator can be active for a 25 min period in every 50 min because of its operation principle and similarly an air conditioner can be operated for 15 min in every half an hour only in the summer months.
The communication-based domestic energy management scheme proposed in this work aims at reducing home electricity consumption charges, decreasing the electricity bill of the consumer by shifting the appliances operation from peak demand hours to off-peak ones. As mentioned above, BluHEMS involves communications among smart appliances, a central EMU and a WSHAN. The conceptual interaction of these entities is depicted in Figure 1. As it is possible to see, the decision making center is represented by the EMU.
The consumer may turn on any appliance at any moment of the day without taking into account that, at that moment, it can be also in peak hours. BluHEMS allows the switching on of the appliance or suggests to the consumer which is the more appropriate start time. In fact, when an appliance is turned on it sends a request to the EMU that checks the available stored energy in the storage system. Moreover, the EMU communicates also with the smart meter in order to know about the updated prices in that time slot. When the EMU receives the information about the amount of stored energy, it schedules a convenient start time for the appliance according to the proposed BluHEMS algorithm, described in Section III, and notifies it to the consumer.
At this stage, the consumer can decide whether to accept the schedule proposed by EMU, for instance the time period falls during peak hours or the level of stored energy is not enough, or to ignore it switching on the appliance. The proposed approach is not limited to the appliances that operate mostly autonomously and on a periodic basis, such as refrigerators, washers, etc.. In fact, the proposed approach is valid and enforceable on all household appliances. For instance, considering a specific case, the system could suggest, through the smart plug, to wait after the consumer is about to start drying hairs after taking a shower when connecting and turning on the hair dryer. Whereby, the consumer can reject any scheduling proposal since it has the need to use the hair dryer at that precise moment. On the contrary, the consumer could prefer to remain with wet hair (or dry them with a towel) in order to shift the appliance cycle to hours where electricity prices are comparatively low. A different conclusion can be deducted if the appliance taken into account is not a hair dryer but a vacuum cleaner, an iron, etc., in which, for example, if the consumer agrees, it is possible to postpone its use following the timing suggested by the proposed algorithm. This run-time mechanism of acceptance or rejection of the schedule can be managed through smart plugs. In this paper smart plugs have not been analyzed in detail because the main aim is to present the entire energy management approach. In any case, it is obvious that in the market there are several devices that allow to implement this mechanism of interaction between the consumer and household appliances that is introduced in this paper.

A. Wireless Sensor Home Area Network

Wireless networks can be a great candidate for in-home applications because of their scalability for adding new appliances to the system easily. Both the power consumption and the amount of usage time of each appliance can be transferred through a wireless link and the on/off control on loads can be provided with commercially available “smart plugs”. Several wireless technologies, such as Bluetooth Low Energy (BLE) [27], IEEE 802.15.4/ZigBee [28] and IEEE 802.11/Wi-Fi [29], that can support the remote data transfer, the sensing and the control, have been proposed in order to embed various levels of intelligence for smart homes. These protocols can use existing infrastructure, anyhow there is a main requirement that make a wireless protocol ideal for use in smart homes, that is the energy efficiency. In many cases, the sensing nodes are batterypowered, so a low-power feature is a basic requirement both for the energy consumption of the entire house and for economic savings. For this reason the choice of the proper wireless protocol is a key feature in WSHANs. BLE operates in the 2.4 GHz ISM band with only 40 channels spaced 2 MHz apart. It is capable of transmitting at a rate of 1Mbit/s using GFSK modulation. Like Bluetooth Classic, it uses frequency hopping, but it uses an adaptive frequency hopping and has a slower rate. BLE uses 3 of the 40 channels to advertise which allow the device discovery. After a device is discovered and connected the remaining 37 channels are used to transmit data. In a Piconet of Bluetooth Classic each Master device establishes the frequency hopping sequence and can have up to 7 Slave connections. This is no such limitation in BLE and in fact, “theoretically”, to a Master node can be connected “hundreds” of Slaves. The relatively short transmission distances between the electrical appliances and the limited amount of the data to be transmitted in a certain time interval can be deemed as other important factors in the selection process of BLE protocol. It is useful to note that the range of BLE radio may be optimized according to application. The majority of Bluetooth devices on the market today include the basic 30 foot (or 10 meter) range of the Bluetooth Classic radio, but there is no limit imposed by the specification. With BLE, manufacturers may choose to optimize the range to 200 feet (about 67 meters) and beyond, particularly in home sensor applications where longer range is a necessity.
The proposed network architecture, depicted in Figure 2, is composed by several independent Wireless Home Automation Cells (WHACs), managed by a BLE Master device that acts also as EMU and integrates the smart meter module. The WSHAN, based on BLE, is composed by all the WHACs within which there are the Field Devices (FDs), that are Bluetooth Low Energy devices dealing with a specific task or are associated with home appliances through smart plugs.

The proposed WSHAN enables a variety of use cases, for this reason a non-exhaustive list of examples is provided below:

• light control: lights can be controlled from any switch in order to reduce the need of new wired connections. Lights can also be activated in response to a command from a remote control. Moreover, they can be turned on automatically when presence and luminance sensors detect that people are in a poorly illuminated room.

• smart energy: window shades, HVAC, central heating, and so on may be controlled depending on the information collected by several types of sensors that monitor parameters such as temperature, humidity, light, and presence. Whereby, unnecessary waste of energy can thus be avoided. Furthermore, smart utility meters can be used to detect usage peaks and alert the household devices that may be causing them.

• security and safety: advanced security systems can be based on several sensors (e.g., smoke detectors, glassbreak sensors, and motion sensors) in order to detect possible risk situations that trigger appropriate actions in response. For example, smoke detectors may activate fire alarms.

• remote control: over the years, infrared technology has been used for wireless communication between a remote control and devices such as TVs, Hi-Fi equipment, and heating, ventilating, and air conditioning systems. However, infrared requires line-of-sight and shortdistance communication. Radio frequency technology overcomes these limitations.

Some of the WHACs of the proposed architecture behave as WSNs and then they can continuously monitor environments with less human effort and are low cost and low power. Through wireless communication, the Master node receives and processes data detected by FDs placed inside the WHAC. It also allows sending user commands or system commands to FD nodes. Moreover, wireless links allow the communication among mobile devices (such as smart-phones or tablets) and the WHACs. Whereby, people can authenticate themselves inside the home automation system and subsequently monitor data detected by sensor nodes and, in case of need, send commands.

B. Motivation of the wireless protocol choice

The proposed WSHAN is based on the Bluetooth Low Energy protocol [27]. This standard satisfies the requirements such as very low power consumption, low cost and appropriate range of operation for indoor applications [30]. This wireless protocol has been chosen for several reasons. In fact, Bluetooth Low Energy has a high potential in becoming an important technology both for the Internet of Things in low power, low cost, small devices and for smart homes. The lack of native support for IEEE 802.15.4 in mobile devices (smartphones, tablets, laptops, etc.) is a problem especially for mobile or temporarily mobile use cases. The ecosystem with phones, tablets, laptops and phone accessories will drive down the cost for BLE. However, there are still use cases where IEEE 802.15.4 based technologies are used especially in areas where it is already established. In spite of its installed base in smart energy, home and building automation applications, IEEE 802.15.4 faces competition in BLE in these applications as well. Anyhow, Bluetooth Low Energy has a lower energy consumption than IEEE 802.15.4 and for this reason may be the best choice in applications of home automation. IEEE 802.11 is used in devices where cost, low power is less important and as a wireless backbone combined with the other wireless technologies.

In literature there are several works in which a wireless network supports a smart grid. For instance, Erol-Kantarci and Mouftah presented several works on this topic [25], [31], [32], [33]. Their proposed wireless network is based on IEEE 802.15.4 that coordinates the communication among home appliances managed by a HEM scheme. In a more recent work Mahmood et al. [26] have extended the approach proposed in the papers of Erol-Kantarci and Mouftah introducing a new energy management approach for smart homes. Even in this case, the authors propose a wireless network based on IEEE 802.15.4. In this work a comparison is carried out with the scheme proposed by Mahmood et al. [26] because it has been published more recently, it extends the approach presented by Erol-Kantarci and Mouftah and, mainly, because is the one that is closest to BluHEMS. Furthermore, it would be useful to make a comparison with a HEM approach supported by a BLE wireless network but, unfortunately, to the best of our knowledge, there are no works in the literature in which Bluetooth Low Energy is applied in a wireless network that supports a HEM scheme.

Home automation is a n intelligent, functional as a unit system that facilitates home processes without unnecessary complicating the user’s life. Devices can be connected, which in turn connect a nd talk through II centralized control unit. which a re accessible via mobile phones. Th ese devices include lights, appliances. security systems, alarms and many other sensors and del ices. This paper presents the design and implementation of a Bluetooth based smart home automation system which uses a Peripheral interface controller (PIC) microcontroller (16F’1937) as the main processer and the appliances are connected to the peripheral ports of the microcontroller via relays. The circuit in the project was designed in Dip trace software. The PCB layout design was completed. The fully functional smart home prototype was built and demonstrated to functional.

INTRODUCTION

Smart home automation is the practice of using internet enabled device s to remotely and automatically control appliances, in and around your home. You could use your phone to control most of these appliances. Smart homes are gain in popularity day-by-day with some numerous benefits. Industries and researchers are working hard to build sustainable and low cost automatic systems to monitor and control different machines like lights, fans and motors. Smart phones can be used to control dev ices in a smart home. Systems based on the Bluetooth protocol are faster than most of the other technologies [I ]. Bluetooth is very effective for serial data communication where data can be transmitted at speeds of up to 3 Mbps at a distance of I0 – 100 m. Automation systems not only alleviate the wastage of electricity in a house but also reduce human effort in switching on and off home appliances .

Home automation is an important application of wireless technologies like Bluetooth. Homes require sophisticated control of different gadgets such as electronic appliances [2]. Home appliances can be integrated to smart phones via Bluetooth as in [3]. Bluetooth works at a frequency range of 2.4 GHz over a distance of 100 m with a speed of I Mbps. This is an efficient solution for controlling the process of home automation. A microcontroller can be used as a device controller for home devices. The significance of using the Bluetooth protocol for communication in a smart home stems from the fact that. Bluetooth is found in nearly every cellphone today. Hence having a smart home. where the microcontroller is Bluetooth enabled, makes it possible to easily control most devices with the aid of your cellphone which can save a lot of cost. Secondly most homes are not more than 200 m2 in floor area and Bluetooth protocol can cover a perimeter of a couple 100 meters hence this is the appropriate techno logy for this application.

The aim of the project is to construct and implement a smart home automation system using Bluetooth technology and android smart phone to control home appliances through smart phone application. Facilitate the use of technology for home appliances which will reduce electricity wastage and increase house safety. To implement a reliable and low-cost home automation system that can be used to access electrical appliances at home.

LITERATURE REVIEW

Information technology can be used in smart homes to control appliances as in [4]. The main objective in the development of smart homes is to be able to control home appliances to make the life of people easier. Researchers are currently improving the technology behind the smart homes in order to make them more easily affordable.

Smart homes can tel1 you the status of connected devices at home through a user-friendly interface as in [5]. Some of the major communication technologies used in smart homes include Bluetooth. WiMAX. Wireless LAN(Wi-Fi). ZigBee. and GSM for Mobile communication [5]. The research work in [6] gives details to control home appliance s via wireless communication between an Arduino ( Bluetooth) device and cell phone using the Bluetooth technology. In a smart home two kinds of communication can be utilized wireless and wired as can be seen in [7]. Wireless normally occurs between the smart phone and the microcontroller and wired between the controller and the dev ices. A Graphical user interface can also be developed for the phone. Earlier on smart home automation systems where plagued by high costs as described in [8]. but as time passed and the development in technology. devices became smaller in size and smart home automation systems became more cost effective and popular. Smart home protocols that can be used include X10. ZigBee, Lon Talk and CEBus.

Everything seems to matter in the environment; the need for sustainable development is an important factor towards the future of man. The world summit on sustainable development at Johannesburg in 2002 has brought to the attention of people around the world the deteriorating condition of our environment. It is clear that no person in the world can afford 10 be ignore the problems we have in the environment.

Environmental management has captured the attention of healthcare workers. Managing environmental hazards has become very important. Home automation systems can enable home owners to control and monitor home appliance s from Energy efficiency has become a very important part of energy policy in many countries because, energy saved in megawatts contributes to security of supply, sustainable energy prices and environmental protection [9].

The international Energy Agency (lEA) refers to energy efficiency as ” first fuel”, considering it to be a major energy resource. In 2009 their analysis showed that by 203 5 two-thirds of the economic potential of energy savings would be lost if the policy activity is not increased [10].

Bridging this efficiency gap requires owners of commercial and residential properties to lake action. The decisions of single family homeowners will collectively have an influence on the energy future. The proportion between utilization and generation of electricity is a research topic addressed by smart grids. Smart grids research also deals with energy storage, distribution automat ion. demand response etc. The intention of smart grids is to make electricity more reliable. Peak load is a term used in energy demand management and refers to a period when electrical consumption is significantly higher than the supply level. Smart home management systems can be used to reduce the electrical consumption and hence the peak load. Systems that control themselves are becoming more intelligent and independent. Internet of Things (IoT) can assist to achieve improved connectivity to machines. systems and smart homes. Internet of th ings can connect to smart homes in order to improve the control of smart homes. Fig. 1 shows the transition from the network, to the internet. to the mobile-internet. 10 mobile phones and people and finally to the intern et of things and smart homes control.
The device s in the smart homes can be computers, household de vices. industrial equipment or any other dev ice that you can assign an (Internet Protocol) IP address to. Devices will the reform be able to transfer data over the network. loT will be able to join digital entities and have a new class of functionality.
This is the future of smart homes. Currently smart homes can operate with sensor and electronic devices connected to home areas. but in the future loT will integrate with devices to achieve home automation systems. Then control of devices in the home will be attainable from everywhere, because these devices can be connected to the internet.

Fig.1 From internet of People to internet of Things
Humans have developed technologies to achieve advancement goals. Improvements in technology have resulted in improvements in social structures. The industrial revolution brought improvements to socio-economic structures. These anywhere. give them control over energy consumption. enable them control cost of utilization and contribute to the improvement of environmental issues. advances in technology makes it possible to automate work done by humans. The advancement in technology can lead to reduction in jobs done by humans. Human workers could be replaced by automation processes. Although technology may remove some jobs it can also create new ones and in addition to these create wealth in society.
Recently there has been an increase in the use of smart home technology in the United State s. The digital revolution has led to a new exciting period in companies dealing with home automat ion. offering customers improved home technologies. Leading to interconnected. easy-to-u se environment called a ” smart home” . These devices enable customers to be able to monitor smart homes and have less utility costs.
The growth in this sector (smart homes) has occurred as a result of rise in energy costs. lowering of the cost of smart home technologies and government policies providing incentives toward s reducing energy consumption. Smart homes are important for strategic planning and national policy. For a technology such as smart homes to be adopted it is necessary to make sure that you have clear benefits and acceptable levels of risk. In [17] the risks and benefits are measured to determine if smart home technology should be completely adopted into the market. In addition to that they study how to reduce the risks of using smart home technology and increase its benefits.
Smart homes can also assist to reduce the effect of greenhouse gases as we ll as increasing energy efficiency. There are solutions that make use of information technologies (ICT) (18) to be used in smart homes. These solutions will involve a smart home that uses the full range of lCT based energy management method s. In [18] the consumer perception of using energy management methods are also studied. The re they discuss issues of smart metering. variable tariffs, smart appliances and home automation .
Smart homes can be used to assist the elderly and the disabled in a not obstructive way [19]. This ca n assist the elderly and the disabled to be independent. have good health and prevent them from stressful conditions due to isolation. Smart homes can have sensor and actuators that work in a network environment and collect data. Once the data is collected it can be used to determine the assistance measures required by the elderly. In some instances, the technology can include wearing implants 24 hours a day to assist the elderly and disabled.
III. METIlOIX)!.(XjY
This project consists of two main modules which are the hardware module that interfaces with the home peripheral components and the software module that communicates with the microcontroller using Bluetooth. The system uses Bluetooth as the radio communication protocol which acts as the link between the smartphone and the PIC microcontrol1er.

A. implementation

The PIC microcontroller and Bluetooth module are used in the project to control the whole process. The android application on the smart phone is used to send commands to the PIC microcontroller. via wireless Bluetooth. The PIC microcontroller is connected (hardwired) to three relays as shown in Fig 2. In this project these relays are connected to different electrical devices. As per the block diagram, a 12 VDC LED bar, 220 VAC Gate motor, 220 VAC light bulb I and 220 VAC light bulb 2.

Fig. 2 System block diagram
Fig. 3 shows the schematic design of the project. The circuit was designed using Dip trace software. The schematic design shows the micro controller, relays, voltage regulators and other peripheral components.

The PIC microcontroller is used to control the whole process. Bluetooth is used as a protocol to communicate between the application on the mobile phone and the receiver on the Bluetooth console linked to the PIC. As a result. this controls the home appliances. Icons on the mobile application interface as can be seen in Fig.4 can be used to send different commands to the receiver on the Bluetooth console. The Bluetooth console communicates with the PIC which will trigger an appropriate relay that can switch “ON” and “OFF” an appropriate device.

Fig. 4 Mobile Phone Application

Fig.5 below shows the flow diagram for the design of the code written for the PIC microcontroller, in order to operate the Bluetooth console linked to the PIC and the relays connected to the home devices. The first step in the flow chart start the Bluetooth module. the next step sets the baud rate of communication to 9600 b/s. Then the voltage is obtained from the temperature sensor and assigned to a variable. Subsequently the Bluetooth console communicates with the smart phone. the value of the temperature is then displayed on the smart phone.
Any Setting sent form the smart phone to the Bluetooth console and the microcontroller is then used to determine the duty cycle for the control of the relays connected to the peripheral devices.

RESULTS

When the user presses the “LED bar button icon in the application the led bar will switch “ON” . The led bar can be switched “OFF”, by pressing the icon again. The same process is followed to control the other devices. The process is summarized in table I below.
TA BLE I API’U CATION CONTROl.

We need to protect our environment from many harmful things in the world, such as pollution. saving energy to preserve the beauty of nature. We need to start saving electricity and other energies consumed. You can save electricity by scheduling the “ON and “OFF” time of all electrical appliances, The utilization of loT technology cart enable you switch of devices that are not in use from a remote location as long as the devices in the smart homes have an IP address linked to them.
This can further lead to a reduction in the utilization of energy consumption of homes.

V. CONCL USIO N

This project reports on the design and implementation of a low cost. flexible and wireless solution to home automation using a PIC microcontroller, an android application and the Bluetooth protocol. It gives a brief review on different types of home automation systems, The home automation devices in this paper are controlled by using an android application on a cellphone and the wireless Bluetooth protocol. The devices in the prototype are hard-wired to the PIC microcontroller. These devices can be switched “ON” and “OFP’ remotely and conveniently saving the utilization of electricity. The home devices controlled in this project include, lamps. LED, and a gate motor. Researchers around the world are working on integrating technology in home automation to make devices more intelligent and feature rich.