Submitted by
RAMKUMAR.S
ELLAVARASAN.U
SENDHIL KUMAR.V
INBARASAN.K

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ABSTRACT
The Need for security to the house when we are in and moving along to the office will be great constraints for us. The communication has brought a way to secure the properties of our home. “GSM BASED HOUSE MAINTANENCE AND SECURITY SYSTEM FOR LEGLESS PEOPLE” is a boon for legless people to easily control and monitor their houses from the place where they are right now by using their ordinary mobile phones. It serves two main objectives that is house maintenance and also offer increased security system.
The first objective House maintenance is achieved by using microcontroller and relay circuit. The authorized person gives the acknowledgement to that device, then the microcontroller will switch on or off the electrical appliances and send the state of that appliances whether they are currently working or not. The authorized person can done this by using their normal mobile phones.
The second objective of our paper is to offer increased house security that is when there is any intrusion or unauthorized entry the alert message is send to owner. Who can close the door and enable the security alarm system by sending a coded message to prevent from any actions of intruders.
1. INTRODUCTION
In this project the keypad consists of set of keys with LCD display is placed on near to the lock of the door which is used to enter the password in the microcontroller. The authentication person’s passwords are stored in the EEPROM which is non volatile memory the stored password will not be deleted even though power is switched off.
The mobile phone is interfaced with the microcontroller through RS232 and data cable. The RS 232 is used to converts the TTL logic to RS232 logic. The data cable is the special type of cable which is available with mobile phone. Here the microcontroller is the flash type reprogrammable microcontroller in which we have already programmed with authorized person’s phone number.
When the person wants to open the door, he should press the switch and has to type the password. The microcontroller checks whether the given password is valid or not. If it is wrong one the door will not opened.
The IR sensor is used to monitor the door that is currently opened or not, or else he makes any misuse like to damage the door and try to open it without giving the password means the microcontroller sends SMS to authorized person. If that authorized person gives the acknowledgement to that device, then the microcontroller locks the door, and enables the alarm system.
It is also to control the electrical appliances in the house like light, fan, TV and all. The person can easily switch on or off the devices and can know about the status of devices from where the place he is seated by simply sending a message.
1.1. RESOURCE REQUIREMENTS
1.1.1. HARDWARE REQUIREMENTS
Processor : Intel Pentium IV 933 MHz Speed
Hard Disk : 80 GB
Main Memory : 512 MB
Cache Memory : 256 KB full speed
Monitor : 14’’ SVGA Color Monitor
Keyboard : 110 Keys Standard Keyboard
Mouse : 2 button with scroll
Microcontroller : 8031/51 Series (ATMAL Family)
Data Cable : RS-232 Cable
Display : Liquid Crystal Display (LCD)
Keypad : Matrix Keypad
Alarm : 12v buzzer
Electrical Appliances : Light, Fan
Power Source : 230v
Additional Battery : 6v
Sensor : Infra Red Sensor
Transformer : Step-down Transformers (12 V & 5V)
1.1.2. SOFTWARE REQUIREMENTS
Operating System : Windows 2000/xp
Language : Embedded C
Processsing : Keil’s IDE
1.1.3. SOFTWARE PROFILE
1.1.3.1. Embedded ‘C’
C is the language of choice for programming larger microcontrollers (MCU), those based on 32-bit cores. These parts are often derived from their general-purpose counterparts, and are both as complex and feature-rich. As a result, C (and C++) compilers are necessary and readily available for these MCUs.
In contrast, designers who have chosen to use 8-bit controllers have usually resorted to hand-coding in assembly language. While manual assembly programming for precise control will never go out of style, neither will the push to reduce costs.
There are advantages in compiling high-level C language to even the limited resources of an 8-bit MCU. Automatic generation of code for repetitive coding tasks, such as arithmetic for 16-bit or longer data types.
Intuitive treatment of hardware peculiarities. Reading from or writing to a serial flash memory device can be represented in C as a simple assignment statement, although the store operation requires some coding.
Platform - independence. The same cross-platform capabilities that C brings to desktop computing are available for the range of 8-bit microcontrollers on the market today. This text shows you how to use C to program an 8-bit embedded MCU. We hope you are familiar with C, but require in-depth information about microcontroller programming.
The main example project in this text is a computer-controlled thermostat. From an initial specification, we progressively refine and augment the device in the same manner as any other consumer or control product. With software development as our focus, we make choices and tradeoffs that any designer will need to make.
Characteristics Present In Embedded System
• Embedded systems are designed to do some specific task, rather than be a general-purpose computer for multiple tasks. Some also have real-time performance constraints that must be met, for reasons such as safety and usability; others may have low or no performance requirements, allowing the system hardware to be simplified to reduce costs.
• Embedded systems are not always standalone devices. Many embedded systems consist of small, computerized parts within a larger device that serves a more general purpose. For example, the Gibson Robot Guitar features an embedded system for tuning the strings, but the overall purpose of the Robot Guitar is, of course, to play music. Similarly, an embedded system in an automobile provides a specific function as a subsystem of the car itself.
• The program instructions written for embedded systems are referred to as firmware, and are stored in read-only memory or Flash memory chips. They run with limited computer hardware resources: little memory, small or non-existent keyboard and/or screen.
Embebbed Software Compiler Tools
As for other software, embedded system designers use compilers, assemblers, and debuggers to develop embedded system software. However, they may also use some more specific tools:
• In circuit debuggers or emulators (see next section).
• Utilities to add a checksum or CRC to a program, so the embedded system can check if the program is valid.
• For systems using digital signal processing, developers may use a math work bench such as Scilab / Scicos, MATLAB / Simulink, EICASLAB, MathCad, or Mathematica to simulate the mathematics. They might also use libraries for both the host and target which eliminates developing DSP routines as done in DSPnano RTOS and Unison Operating System.
• Custom compilers and linkers may be used to improve optimisation for the particular hardware.
• An embedded system may have its own special language or design tool, or add enhancements to an existing language such as Forth orBasic.
• Another alternative is to add a real-time operating system or embedded operating system, which may have DSP capabilities like DSP nano RTOS.
Debugging
Embedded debugging may be performed at different levels, depending on the facilities available. From simplest to most sophisticated they can be roughly grouped into the following areas:
• Interactive resident debugging, using the simple shell provided by the embedded operating system (e.g. Forth and Basic)
• External debugging using logging or serial port output to trace operation using either a monitor in flash or using a debug server like the Remedy Debugger which even works for heterogeneous multi core systems.
• An in-circuit debugger (ICD), a hardware device that connects to the microprocessor via a JTAG or Nexus interface. This allows the operation of the microprocessor to be controlled externally, but is typically restricted to specific debugging capabilities in the processor.
• An in-circuit emulator replaces the microprocessor with a simulated equivalent, providing full control over all aspects of the microprocessor.
• A complete emulator provides a simulation of all aspects of the hardware, allowing all of it to be controlled and modified and allowing debugging on a normal PC.
Unless restricted to external debugging, the programmer can typically load and run software through the tools, view the code running in the processor, and start or stop its operation. The view of the code may be as assembly code or source-code.
Because an embedded system is often composed of a wide variety of elements, the debugging strategy may vary. For instance, debugging a software- (and microprocessor-) centric embedded system is different from debugging an embedded system where most of the processing is performed by peripherals (DSP, FPGA, co-processor). An increasing number of embedded systems today use more than one single processor core. A common problem with multi-core development is the proper synchronization of software execution. In such a case, the embedded system design may wish to check the data traffic on the busses between the processor cores, which requires very low-level debugging, at signal/bus level, with a logic analyzer, for instance.