The rapid development in science and technology has paved its way for sophistication by automation. People now a days, are inclined towards devices that are sophisticated, simpler to use and secure. In this project entitled “Home Appliances Control using Different Controlling Modes “, a prototype is developed which shows how the best utilization of technology can be made in order to secure a home not only from threat but also by ensuring all the safety measures. The project also throws light on the sophistication of the house by monitoring and controlling the devices using RF and VOICE technologies.
The main motto of the project is to ensure complete safety and automate all the devices. This is done by interfacing all the devices to a PIC microcontroller”PIC16F84A”. Apart from alerting the user regarding threats a feature is provided where the user can monitor and control all the devices such as tube lights, fans, air conditioners, refrigerators etc. whenever there is a power cut the user is immediately intimated.
A home appliance control system (HACS) is a system which provides various services to remotely operate on home appliances, such as microwave oven, TV, and garage door etc through remote devices such as mobile phone, desktop and palm-top. This project is designed to make home automation easy to control when a user is not at home. The project is designed to allow easy use of a RF and VOICE modes to control appliances in the home. Using a RF and VOICE modes the development of the control system will be carried out. These modes will communicate to control the devices attached to microcontroller modules. When the action has been carried out then a response is sent to the user. The project involves three main areas, research, developmentprogramming, testing and the writing of the report.
The Home appliance control system is controlled by using RF and VOICE modes. It controls various appliances such as a microwave, TV etc. The HACS system receives commands from remote devices that are manipulated by user. The system in turn dispatch commands to respective appliances that will perform the actions. HACS is responsible for keeping track of the states of the devices. If something goes wrong, it will notify the user by sending command back to the remote devices as well as emergency department if necessary. The system administrator of the HACS system has the ability to add a new appliance or delete an existing one. The system administrator has the ability to add a new remote device and configure it with HACS or delete an existing one when it is not used. Also the system administrator can create an account for a new user or delete existing account if it is no longer used.
CHAPTER 2
PREVIOUS TECHNOLOGIES
2.1 INFRARED (IR) BASED HOME APPLIANCES CONTROL
IR extension is a previous proposed system which is implemented over certain range. A control system is being implemented in such a way that. The control system would be designed to control the units at remote location, using web-enabled interface (either GPRS) and remote location would be interfaced to the appliances to the Infrared interface. This idea is extendible to the Bluetooth interface as well instead of Infrared (wherever applicable) but the current paper would be focusing on the Infrared as a remote appliance control.
IR always needs a line of sight and we will need a robust feedback mechanism, to verify the operations, we are not focusing the efforts towards deploying Bluetooth instead of IR is because, practically speaking, most of the home appliances are not Bluetooth enabled today (eg. Refrigerator, TV, Music Player, PC, Heaters etc) and specifically there will be changes required on either ends in case we need to use Bluetooth instead of IR. Hence to us, today, IR looks most suited to be used from applications perspective.
To access the control unit, the user should start with first sending an authentication code along with the desired function to his home control system via GPRS. Upon being properly authenticated, the computing system at home (control unit) would relay the command through IR port to home appliances.
The control unit would relay the commands to an IrDA Transceiver that would perform the required action. A return function code (feedback) would be sent to user’s cell phone. This system is the general mobile devices and developed with Java technology. The system controls the home appliances with the mobile device and sees the states of home appliance via Internet. Finally, we demonstrate the system applications examples and share the development and implementation experiences.
2.2 BLUETOOTH BASED HOME APPLIANCES CONTROL
The use of electronic controllers for controlling electrical home appliances can be found widely around the world especially in the developed countries. By time, wireless technology such as infrared light communication. This wireless technology is widely commercialized and can be found almost anywhere. Though appealing, it still has a weakness due to the use of infrared light as data transmission medium. When there are objects blocking the infrared receiver, the process of controlling those electrical appliances becomes difficult due to the point-to-point or line-of-sight communication mode.
From this situation, came the idea to create a wireless electronic control system utilizing Bluetooth technology for data transfer and control of electrical appliances. PIC 16F84A microcontroller acts as a “brain” for this system in executing the tasks and operations according to the user’s wish. This system’s Graphical User Interface (GUI) is developed using Microsoft Visual Basic Express to enable the user to control and understand the system in controlling electrical appliances easily.
In this project, a system that uses the application of Bluetooth Appliances Control System” is a development to further enhance the infrared remote control systems. Generally, this system is related on how to control any objects like appliances and machines. A Personal Area Network (PAN) would be created in order to control the appliances. This PAN uses the Bluetooth as the medium of communication. Nowadays, almost every equipment and machine has their own control method in order to run or operate them.
In this model of controlling through Bluetooth can in particular be implemented in high voltage equipments. Ozone water treatment is an example that needs high voltage supply and high voltage circuit breaker. In ozone water treatment, initial process is the molecule of Ozone; O2 must be isolated or separated to become atom O- by injecting the high voltage power supply. So, the manual control is improved to Bluetooth wireless technology replacing cables in order to inject the high voltage.
The main objective for this project is to design and develop a system for electrical appliances which is easier and simple to control. Using a laptop and Bluetooth as the medium of data transfer to the custom designed of appliances, the user can simply switch on or off those appliances on the laptop to switch the appliances on or off. Another objective is to control the electrical appliances at the certain distance using wireless without having to manually switch those electrical appliances on or off. This system is suitable to be used in room, lecture halls, laboratories, offices and hotels. CHAPTER 3
PRESENT TECHOLGY USED
3.1 BLOCK DIAGRAM
As we are using RF and VOICE module so they both contribute for the controlling of home appliances. Which are used for controlling home appliances (e.g., fan, tv, refrigerators). RF and VOICE sends input to the 16F84A. So that it performs execution of pertaining input program. So that 16F84A performs the specified operation and amplify output voltage of microcontroller and sends to the 12V DC relay in order to operate the home appliances according to the desire input given.
Fig 3.1 Block diagram of Home Appliances using RF and VOICE modes
3.1.1 Voice Based Wireless Remote using RX-TX MODULES
Voice based industrial electrical appliances control is an interesting voice based project, mainly useful for industrial applications, home automation. This project gives exact concept of controlling a high voltage electrical device or DC / AC motor a voice instruction. This project is the first step to design of voice based industrial automation projects.
The speech recognition system is easy to use programmable speech recognition circuit. Programmable, in the sense that the system to be trained the words (or vocal utterances) the user wants the circuit to recognize. This board allows us to experiment with many facets of speech recognition technology. It has 8 bit data out which can be interfaced with any microcontroller. Some of interfacing applications which can be made are controlling home appliances, robotics movements, Speech Assisted technologies, Speech to text translation, and many more.
Fig 3.2 Block diagram of VOICE module
The 16F84A microcontroller contains thirteen ports of each eight pins. In this project one port is dedicated for speech recognition. Relays are interfaced through ULN driver circuit to control the electrical appliances. A simple yet powerful program is written in assembly language and burned into the microcontroller to record and accept voice instructions and to control the devices. A 8 x 2 LCD with contrast control preset is provided for status display.
Voice module uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.
Speech recognition will play an important role in future human–computer interaction. In fact the field of speech recognition is a part of the ongoing research effort in developing computers that can listen and understand spoken information. But some time, current automatic speech recognition (ASR) systems’ recognition rates decrease significantly in presence of environmental noise. Voice control means the ability of a machine to react to spoken commands. The aim of this paper is to provide enhanced access to machines via voice commands. However, it is a topic of comparison between well-established conventional means of input, e.g. switch and voice triggering.
To convert an ordinary home as a smart home, all appliances must be controllable through computer. . As we know PCs are provided with input/ output ports, which makes easily to interface PC with the real world applications. The interface is the combination of hardware and software embodies the hardware is an electronic circuit that used to trigger the appliance, and the software is the programming of the PC to manage all Input/output signals to its ports, hence, the interface hardware circuits.
For the purpose of interfacing with the real time control applications, the PC parallel port is used. But there is some restriction if we are using parallel port then converting it as wireless circuit will be little bit tough. Since the parallel port works well as hardware interfacing the parallel port pins are TTL levels output (originally derived by a 74LS374 octal latch). This means that they put output 0 to 0.8 dc volt logically 0, and 2.4 to 5 dc volt logically 1. According to the parallel port behaviors, there are 8 bits for data input/ output, which can produce 256 different control signal statuses.
The data bit signals, can be managed by software that applied for this purpose, the powerful scripting language is Aotoit which can access the ports more efficiently than other available computer program languages. Inside the program by using the command local could be used to directly access all data port signals , There are many ways could be used to control all home’s appliances by sending appropriate signals to the PC’s ports, parallel or serial. Then these signals inserted to the interface hardware system that prepared, designed and matches with the output signals, then depend on the signal, the interface hardware control or manage one or more of the home appliances.
3.1.2 RF Based Wireless Remote using RX-TX MODULES
Transmitter module:
Receiver module:
Fig 3.3 Block diagram of RF MODULE Rx and Tx
The RF module (Tx/Rx) for making a wireless remote, which could be used to drive an output from a distant place. RF module, as the name suggests, uses radio frequency to send signals. These signals are transmitted at a particular frequency and a baud rate. A receiver can receive these signals only if it is configured for that frequency.
A four channel encoder/decoder pair has also been used in this system. The input signals, at the transmitter side, are taken through four switches while the outputs are monitored on a set of four LEDs corresponding to each input switch. The circuit can be used for designing Remote Appliance Control system. The outputs from the receiver can drive corresponding relays connected to any household appliance.
• General Description
✓ The ST- RX04-ASK is an ASK superhet receiver module with PLL synthesizer and crystal oscillator
✓ The circuit shape is: PLL
✓ Receiver Frequency: 315 / 433.92 MHZ
✓ Operation Voltage 5V
✓ IF Frequency: 500k
✓ Typical sensitivity: -105dBm
✓ Supply Current: 2.3mA
This radio frequency (RF) transmission system employs Amplitude Shift Keying (ASK) with transmitter/receiver (Tx/Rx) pair operating at 434 MHz The transmitter module takes serial input and transmits these signals through RF. The transmitted signals are received by the receiver module placed away from the source of transmission. The system allows one way communication between two nodes, namely, transmission and reception.
The RF module has been used in conjunction with a set of four channel encoder/decoder ICs. Here HT12E & HT12D have been used as encoder and decoder respectively. The encoder converts the parallel inputs (from the remote switches) into serial set of signals. These signals are serially transferred through RF to the reception point. The decoder is used after the RF receiver to decode the serial format and retrieve the original signals as outputs. These outputs can be observed on corresponding LEDs.
Encoder IC (HT12E) receives parallel data in the form of address bits and control bits. The control signals from remote switches along with 8 address bits constitute a set of 12 parallel signals. The encoder HT12E encodes these parallel signals into serial bits. Transmission is enabled by providing ground to pin14 which is active low. The control signals are given at pins 10-13 of HT12E. The serial data is fed to the RF transmitter through pin17 of HT12E.
Transmitter, upon receiving serial data from encoder IC (HT12E), transmits it wirelessly to the RF receiver. The receiver, upon receiving these signals, sends them to the decoder IC (HT12D) through pin2. The serial data is received at the data pin (DIN, pin14) of HT12D. The decoder then retrieves the original parallel format from the received serial data.
When no signal is received at data pin of HT12D, it remains in standby mode and consumes very less current (less than 1μA) for a voltage of 5V. When signal is received by receiver, it is given to DIN pin (pin14) of HT12D. On reception of signal, oscillator of HT12D gets activated. IC HT12D then decodes the serial data and checks the address bits three times. If these bits match with the local address pins (pins 1-8) of HT12D, then it puts the data bits on its data pins (pins 10-13) and makes the VT pin high. An LED is connected to VT pin (pin17) of the decoder.
This LED works as an indicator to indicate a valid transmission. The corresponding output is thus generated at the data pins of decoder IC. A signal is sent by lowering any or all the pins 10-13 of HT12E and corresponding signal is received at receiver’s end (at HT12D). Address bits are configured by using the by using the first 8 pins of both encoder and decoder ICs. To send a particular signal, address bits must be same at encoder and decoder ICs. By configuring the address bits properly, a single RF transmitter can also be used to control different RF receivers of same frequency.
To summarize, on each transmission, 12 bits of data is transmitted consisting of 8 address bits and 4 data bits. The signal is received at receiver’s end which is then fed into decoder IC. If address bits get matched, decoder converts it into parallel data and the corresponding data bits get lowered which could be then used to drive the LEDs. The outputs from this system can either be used in negative logic or NOT gates (like 74LS04) can be incorporated at data pins.
The RF module, as the name suggests, operates at Radio Frequency. The corresponding frequency range varies between 30 kHz & 300 GHz. In this RF system, the digital data is represented as variations in the amplitude of carrier wave. This kind of modulation is known as Amplitude Shift Keying (ASK). Transmission through RF is better than IR (infrared) because of many reasons. Firstly, signals through RF can travel through larger distances making it suitable for long range applications.
Also, while IR mostly operates in line-of-sight mode, RF signals can travel even when there is an obstruction between transmitter & receiver. Next, RF transmission is more strong and reliable than IR transmission. RF communication uses a specific frequency unlike IR signals which are affected by other IR emitting sources. This RF module comprises of an RF Transmitter and an RF Receiver.