CONNECTIER (Home Appliances Controlling System)

In 21 st century, Smart home concept is playing a major role in day to day life and lives also are much more dependent on electronic devices and smart refrigerator is very popular and attention seeking among these home appliances. Home automation has been increasing vastly in the past years due to much simplicity and affordability for home appliances. Earlier home automation systems were based on technologies like Bluetooth, ZigBee, Z wave and remotely controlled using GSM networks. Currently IOT technology is widely used in home automation which will allow users to control hardware devices through the internet. Smart refrigerators are major part of home automation. Current smart refrigerators come as a single component (as whole complete fridge), which is quite expensive and not affordable for everyone. This research presents a more affordable and useful way to keep track of the food items in the refrigerator using consumption trackers which come as add-ons. The automated approach of controlling the home appliances through mobile and web applications could ease the task using the IOT technology. Because of popularity and flexibility in Android operating system, this mobile application is based on android. The need of a simple and elegant way to keep track of the food items in the refrigerator is the major requirement of this research. A more simple way of allowing people the freedom of having complete control of their home appliances from anywhere is another requirement of this research. Therefore, implementing consumption trackers that can be kept inside the refrigerator, receiving notifications according to the consumption of food items, keeping track of them and a home automation system that reduces energy consumption, protects home environment from secondary effect are the purposes of this research. The result of this research, web and Cloud based home automation system that is flexible and scalable with wide range of home appliances, will promote the growth of IOT. Proposed Home Automation System will help to improve the standard of living at home and allow to increase work efficiency in future.


Introduction
Automation of home appliances is a step of automating the human lives and making them easy to live [1].
In the modern kitchen structure, refrigerator is the most frequently used electronic appliance. With the development of technology, refrigerator has become more smarter. These days The introduction of smart refrigerators which have above stated functions was unsuccessful, because of the consumer's perception of it being an unnecessary product due to its expense which is more than $20,000 [2]. In this research paper, a smart refrigerator add on kits are proposed. These are designed in order to modify the existing normal refrigerator as a smart refrigerator which enables the user to save a huge cost.
Also, this proposed add on kits need minimum level of user interaction. In this kit, the weight changes of the food inside the refrigerator trays will be notified to the user. The weighing task will be done with the use of a load cell module which is connected with the Arduino board. The notifications are sent to the user via an android application or a website. When user takes some food from the refrigerator, the system will notify the weight change of food inside refrigerator trays and notification will be sent to the user's mobile device or web application. Along with the notification, the weight change is further confirmed by the user. Taken as a whole, a conclusion can be made that this research based add on kit will be a revolutionary step in the technology field as well as in the human lifestyle. ISSN 2250-3153 www.ijsrp.org The remainder of this article is organized as follows. In section 2, we revise the related work in terms of the other attempts of smart refrigerators and technologies that were used relevant to the idea proposed in this paper. In section 3, we describe the methodology and design approach around our idea of a smart refrigerator. In section 4, we review the results of the proposed system and section 5 is the discussion about the proposed system. We conclude the paper in section 6and finally in section 7 the references are listed down.

Background
This section explains previous work on home automation based on different technologies. Most of the researches can be broadly classified into two main approaches. One is using short distance wireless communication methods to remote control home appliances and other one is using internet as communication method to remotely access home appliances. implemented an android application in which spoken commands are converted in to a sms and then it is sent to the main controller of the system. In case of emergency system is unable to overcome issue with sms delivery.

Internet / IOT Based Connectivity
Home Automation using IOT include two parts: server and client. These client/server mechanism uses different protocols to convey messages and to control signals through the internet [ implemented 3G/4G mobile cellular accessibility additionally to provide a backup solution in case of no wifi connectivity.

Radio signal Based Connectivity
Radio signal based connectivity has two types of functionalities. One is transmitting and the other part is receiving. These transmitting and receiving functions are done by two different devices (radio signal transmitter and receiver).
These receiver and transmitter require less energy to the devices. It does not require any verification between two devices before the data transmission. Radio signal based connectivity is the best solution for the short distance communication. Disadvantage of the radio signal based connectivity is that anyone with the exact signal transfer frequency can easily receive, send or modify these radio signal.

Hardware Modules Main Controller/ Arduino Mega 2560
With the home automation systems home environment should communicate as a one entity and conserve the energy, be easy to use and energy efficient [13 to 8].
Arduino is an open-source prototyping platform that provides easy-to-use hardware and programming environment. System will update cloud with current environment of home appliances such as temperature, gas and smoke sensors.
Because of clouded database, system will allow users to control appliances such as switching functionalities through mobile application and web application.
Classical home automation system used MYSQL or SQLite to share information sources and to synchronize the status between system users. Those techniques are performance wise very low. This system will use Google Firebase database management system to do fast data exchanges and take datadriven decision on system. Mobile application will be built using Android OS due to its popularity and as well as its open source environment.

Methodology
In this paper, our main goal is to propose a system for home automation. Architecture of the proposed system is shown in the Figure 1.0 as a block diagram exhibiting the connectivity of the system.

Main controller Module
Detector Module ISSN 2250-3153 www.ijsrp.org Figure 1.0 The home automation system consists of two main hardware components. Main Controller and Detector module. Main controller module consists of Arduino mega 2560, RF Transmitter (433MHz), RF receiver (433MHz), and Ethernet shield. Arduino mega requires a lesser operating voltage like 5V. Arduino mega offers a variety of digital and analog inputs, serial interface and digital outputs. Thus RF transmitter and receiver are easily connected to it. RF transmitter and receiver, transmit and receive commands from sensor modules. An Ethernet shield is attached to Arduino mega in order to synchronize data with database and to receive commands via internet.
There are four types of detector modules,  Consumption tracker module  Power controller module  Smoke detection module  Temperature detection module

Consumption tracker module
This module consists of an Arduino pro mini, a load cell that could weigh up to 5kg, a RF transmitter and a receiver and a humidity sensor DHT11 which can measure both humidity and temperature. Load cell module is connected to analog and digital pins in the Arduino pro mini through HX711 circuit. HX711 has two input channels which are analog and we can obtain a gain up to128 by programming these channels. So HX711 module amplifies the low electric output of load cells and then this amplified & digitally converted signal is fed into the Arduino to derive the weight. There is no need for programming the internal registers in HX711. This is the reason behind choosing it. Every control to the HX711 is passed through the pins. HX711 not only has a few basic functions compared with other chips, it also contains high integration, fast response, immunity, and other features. This chip improves performance and reliability at the same time lowering the cost of the consumption tracker module.  Since both temperature and humidity can be measured using the humidity sensor DHT11,it is used to derive values of temperature and humidity.

Power controller module
This module consists of an Arduino pro mini, 5V 10A Relay Switch, RF Transmitter (433MHz) and RF receiver (433MHz). Relay switch is a switch module that is electrically operated and allows users to turn on and off a circuit current which is higher than the micro controller's voltage. It has no connection between the high-power circuit and the low voltage circuit operated by the microcontroller. The relay secures each circuit from each other.
Pin configuration of the relay switch is as follows: required operational voltage to the relay will be supplied by the Arduino mini. Digital output from Arduino mini will be used to change between two channels.  Arduino pro mini will be using a digital reading to check the operational channel of the relay.

Specifications of the 5V 10A Relay Switch
 On-board 5V, 10A  Protected from current using diode  short response time

Smoke detection module
This module consists of an Arduino pro mini, MQ-2 smoke sensor, RF Transmitter (433MHz) and RF receiver (433MHz). The major reason behind choosing MQ-2 Smoke Sensor for our proposed smoke detection module is its sensitivity to smoke and to plenty of other flammable gases such as LPG, butane, propane, methane, alcohol and hydrogen. The resistance of the sensor differs depending ISSN 2250-3153 www.ijsrp.org on the type of the gas. The smoke sensor has an inbuilt regulator allowing the user to alter the level of accuracy of detecting the gas.
Required operational voltage for the MQ-2 smoke sensor will be supplied by the Arduino mini. The output can be an analog signal (A0) which can be read with an analog input of the Arduino or a digital output (D0) which can be read with a digital input of the Arduino. MQ-2 Arduino library will be used to programmatically to convert and derive required readings for LPG, carbon monoxide (CO) and smoke density in ppm. The voltage output of the sensor alters proportionately with the smoke/gas concentration in that particular environment.

Temperature detection module
This module consists of an Arduino pro mini, Arduino Compatible ARD2 Non-Contact Infrared Temperature Sensor GY-906, RF Transmitter (433MHz) and RF receiver (433MHz). The major reason for choosing this sensor is its capablity of sensing between 70°C -380°C down to a resolution of 0.02°C. Operating temperature of GY-906 sensor is 40°C -125°C.
GY-906 sensor includes an unsoldered 4-pin header. Those pins are VIN, GND, SCL, and SDA. Required operational voltage for the MQ-2 smoke sensor will be supplied by the Arduino mini through VIN and GND pins. Two analog readings will be taken from SCL and SDA analog pins. Using MLX90614-Infrared-Thermometer Arduino library, readings will be programmatically converted and required temperature output will be derived.

RF Transmitter and Receiver (433MHz)
RF Transmitters and Receivers (433MHz) are used in main hardware components: Main Controller module and Detector module. RF transmitters and receivers are attached to every Arduino pro mini and Arduino mega 2560 in the proposed system and those are used to transfer and receive data between the main controller and detector module of the proposed system. Arduino pro mini is programed to transfer and receive data simultaneously. Both RF Transmitter's and Receiver's frequency range is 433.92 MHz Figure 6.0

Results
After thorough research, the Connectier team identified the need of a full-fledged system to monitor the home environment and the importance of keeping track of food consumption. According to the user requirements, the development team has implemented a home automation system including a web application and a mobile application. Main controllers controlled by software program are capable of gathering information from other components and uploading to the server, downloading commands and transmitting to other components. It does not have any physical interface (no GUI) to interact with user.
System uses single point of communication which is Google Firebase to maintain real-time environment between hardware and software. Database stores all the system information regarding user, main controllers, detectors and rooms. Object oriented database design allows the deployment of the system to support automatic scaling. It enables the project to go to the commercial level where thousands (or even millions) of main controllers are handled (synced across devices) simultaneously. All the query executions on database will be performed on client device. The android mobile application is a user friendly tool to operate home appliances from anywhere with internet connectivity. The application enables the user to get notified on home environment instantly and real-time. Simply user can turn on/off home appliances which are connected to power controllers. Smoke and temperature sensor will help user to provide safe environment inside homethat can get affected from condition like fire. Mobile application has the ability to alert user instantly in such conditions.

Discussion
The system is expected to be very reliable and accurate. With the independent functionality development, the system was thoroughly unit tested. Unit test levels were important and very effective since most of the problems have been identified and eliminated in early stages of development.
The Connectier team faced so many technical problems from designing phase to implementation phase of the system. Following section lists the problems and tactical actions taken to tackle them.
1. How to connect main controller and firebase real-time database?
The solution was to have a web server in middle so that each device could connect with it and transmit data. Single point of communication will let our team easy to monitor and validate different kind of request comes from main controllers. Server validate data and update Google firebase database through firebase PHP software development kit (SDK).

How to connect main controller and detector wirelessly?
To use and configure the detectors in home environment flexibly, radio frequency has been chosen for transmission between detectors and main controllers. The team used 433 MHz RF transmitter and receiver as the transmission hardware.
3. How to measure consumption of food item in the consumption tracker?
Team decided to mount the load cell below the consumption tracker as it allows continuous weight monitoring. Furthermore, the module is programmatically calibrated in order to respond with consistent values without considering about light weight changes (0-5g).
4. How to maintain real-time behavior between hardware and software?
As a solution, the team chose to adopt a system developed by Google. It is called "Google Firebase Real-time Database". Firebase allows to store and synchronize data between devices real-time and it facilitates to access same database from any device through mobile or web application. Firebase is capable of maintaining an offline cache and automatic synchronization when relevant devices come online.
This research presents a much affordable and a useful way of tracking the food items in the refrigerator using consumption trackers which come as add-ons. The automated approach of controlling the home appliances through mobile and web applications could ease the task of using the IOT technology. Because of the popularity and flexibility in Android operating system, this mobile application is based on android. The need of a simple and elegant way of tracking the food items in the refrigerator is the major requirement of this research. A much simple way of allowing people the freedom of having complete control of their home appliances from anywhere is another requirement of this research. Therefore, implementing consumption trackers that can be kept inside the refrigerator, receiving notifications according to the consumption of food items, keeping track of them and a home automation system that reduces energy consumption, protect home environment from secondary effect are the purposes of this research. The result of this research, web and Cloud based home automation system that is flexible and scalable with wide range of home appliances, will promote the growth of IOT. Firebase real-time database system has been used as the database of this system to make sure that the users will get a real time experience of observation of their home appliances. Proposed Home Automation System will help to improve the standard of living at home and allow to increase work efficiency in future.