24-01-2011, 12:06 PM
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BACKGROUND OF THE STUDY
In the field of home security systems, the methodology of protection is quite different. First is to detect, second to delay, and third to alarm. Home security systems are designed as an integration of several sensor systems.
This is mainly because our system if fully customizable and has quite a lot of features. After the user enables the security system, the green status LED will light up to indicate the system status. User can now enter proper password to unlock the system. If any sensor goes wrong, the LCD will produce an ERROR, thus, indicating the attempt action are mistaken and with proper initial for the sensor (T for temperature, M for motion, S for smoke, D for door or window magnetic switch). The red led light will initially flash at 4Hz to indicate such event. If the buzz alarm is enable, it will sound the tone that user chooses. If the voice alarm is enabled, it will wait for a few seconds (user specified). If the system is still not locked, then it will start playing voice to indicate which sensor goes wrong. (For example, "Temperature Error, please check and unlock the security system.") If another sensor goes wrong after that, the system will also act accordingly and indicate that in the voice alert in addition to the LCD screen. ("Temperature Motion Error, please check and unlock the security system.")
STATEMENT OF THE PROBLEM
Recent news shows that there had been a large increase between home intruder and thief conduct in our society. In addition, home accidents have been experienced by many of the local respondents in the society. There had been a rampant home crimes and attacks that happen almost every minute. With regards to this matter, the situation calls upon our attention in generating this one of a kind proposal. Therefore, problem speculations among the members are made considering the whole safety of the residence. This includes the following:
If in case there is a presence of smoke, the people inside the house will automatically know the situation because of the alarm being detected by the smoke detector sensor. In that case they can prevent fire to happen.
People intruders will be detected if they have to attempt in any part of the doors and windows to open. By the use of magnetic switch sensor connected to the specific area location.
For indoors, temperature sensor are used in climate control systems such as air conditioners, freezers, heaters, refrigerators, and water heaters.
And also motion sensor is design to use in indoor spaces to control electric lighting. If no motion is detected, it is assumed that the space is empty, and thus does not need to be lit. Turning off the lights in such circumstances can save substantial amounts of energy. In lighting practice occupancy sensors are sometime also called "presence sensors" or "vacancy sensors".
OBJECTIVE OF THE STUDY
General:
The general objectives of this project are the following:
To utilize the after-market parts and to build an integrated home security system. Hence the security system will sound an alert when there is an attempt of break-in or if there is possible smoke or fire.
• Reducing loss - Minimizing chances of losing possessions. Losing things can be traumatic and expensive. The alarm system will sound if an intruder tries to get in and most times will scare them off.
• Prevent a confrontation - By having an alarm system, the alarm will sound if an intruder breaks in, so if you come home and the alarm is sounding, you know not to go into your home. This is the best way to avoid a confrontation with a burglar, which can be traumatic for anyone.
• Fire detection - The alarm will sound alerting you to the danger. It will also alert the security company to the danger so they can call for help for you. This could save your family's lives.
Specific:
Specific objectives of the project are:
• To secure the safety of the whole premises in the house.
• To protect the properties and our lives.
SIGNIFICANCE OF THE STUDY
Our home security system is very practical. It can be used not only in the home environment but also in a business environment too. It can monitor the surrounds to not only protect our properties but also our lives. Besides, it can be highly customized to suit each one's need and preference. So our security system is very useful for us as well as other people. We believe every house in the world should equip a security system.
SCOPE AND LIMITATION
The scope of this home security systems are the following:
It can able to detect the temperature range inside a certain residence.
It can also sense various parts of a house including the open and close motion between doors and windows under specified condition establish by the magnetic switches.
The system will automatically produces an alarming sound in connection with the occurrence of a smoke (cigarettes smoke, fire smoke, etc.) inside the house premises.
The System is a boot up-enabled by a password.
The limitations are listed as follows:
• The system is beyond the range of its performance if the situation is established outside the specified area it may serve.
• The system is quite vulnerable to power interruption since it highly depends in an electric driven manner.
ABSTRACT
The result of our design has met our expectation, in which every sensor is working and will sound specific alarm when the system goes into alert status.
The keypad and LCD also offer great interface and users can be familiar with our system in less than few seconds. If we have chance to design this project again, we will add a phone dialer chip like the Zarlink MT8880C we mentioned before. By doing so, we can make sure if no one is at home or if no one is around the area, someone else can be notified to take immediate action.
In addition, we feel like our PORTB is a little bit wasted. We only have 4 output patterns but we are using all 8 pins. Next time we will use 74LS series chip together with only 2 output pins from MCP, so together we can save 6 I/O pins. Besides, we will like to have another small microcontroller at a higher frequency, so we can output our buzz alarm at a higher frequency tone.
There are two kinds of smoke detectors, ionization chamber and photoelectric smoke detectors. Ionization chamber one is more popular due to its low cost. Our smoke detector from home also has an ionization chamber.
However, this kind of smoke detector has a small amount of radioactive material (americium-241), which has a half-life of 432 years (alpha decay). We have checked the specification of such radioactive element and government web pages regarding to such kind of material. We have found such radiation is relatively small as long as we do not inhale or swallow it. The exposure is relatively weak so as long as we are not in touch of it all the time, it is relatively safe to operate the smoke detector.
THEORETICAL / CONCEPTUAL FRAMEWORK
With the increasing prevalence of intelligent home automation, many aspects of a conventional home environment have undergone changes to make living more comfortable, convenient and safe. In home safety, automated security systems play an important role of ensuring that home intrusions are thwarted and illegal trespasses are detected and tracked.
At the forefront of security technology, imaging-based security systems have thrived with growing interest and research work. This thesis delves into the algorithmic design of home security system and which is compose of temperature, magnetic switch, motion, and smoke detection sensor. The system is fully digital and also be fully customized. It incorporated a 16x2 characters LCD display with a 4x4 alphanumeric button keypad. Each sensor can be enabled or disabled, and alarm frequency and skim can also be chosen by users. We have also equipped a voice playback chip, and it will speak which sensor has gone wrong. The logical structure of our design is shown in the block diagram below. The central system will handle all the sensors and keypad input, output information to LCD screen, indicate system status on LED, and make buzz or voice alarm.
