Home Security System:-
Introduction:-
This is a digital home security system with voice feature which can monitor room temperature, smoke, motion, and windows & doors.
The goal of this project is to utilize the after-market parts and build an integrated home security system. Besides traditional magnetic switch equipped on doors and windows, we have also incorporated temperature sensor, smoke detectors, and motion sensor. Hence the security system will sound an alert when there is an attempt of break-in or if there is possible smoke or fire.
The system is fully digital and also be fully customized. It incorporated a 16x2 LCD display with a 4x4 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.
Project Idea
The idea of our project comes from lab 3 when we did a simple security system. However, that security system is quite basic and only offers simple password lock. Hence we would like to enhance our security system with different kinds of sensors. We have also browse some of the old final project and found the "Phone Dialer" project from spring 2002. Originally, we were going to put Zarlink MT8880C DTMF transceiver chip, so it will dial a desire number that user specify. When the phone connected, we will use Winbond ISD1420 voice record and playback chip to play pre-recorded voice signal. However, due to the lack of the phone jack in the lab, plus the majority of the Cornell campus has digital phone line instead of analog phone line, we decided to put away this idea. Since ISD1420 chip has address bit feature, we decided to make our system playback certain pattern of voice when the system goes into alert status.
Logical Structure
The logical structure of our design is shown in the block diagram on the right. 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.
Hardware & Software Tradeoffs
The IR motion sensor is quite inexpensive ($5.99 dollars for the one we got), so we also decided to buy it instead of building one on our own. We also acquire one of the smoke detector from home. This is the very basic version and will sound the alarm when the smoke is detected.Besides some necessary capacitor and resistor connections to the ISD1420 chip, the majority of our project is based on our software. This is mainly because our system if fully customizable and has quite a lot of features. It need to monitors all the sensor, and time the appropriate seconds in order to play certain voice pattern (ex. "Temperature, smoke error, please…" "Door or window error, please…") depending on which sensor goes wrong. It also need to handle the user interface via keypad and LCD screen. All of these are programmed in our software.
Standards
The 16x2 LCD we use has standard 16 pin connection (pin 15 and 16 for LED backlit power). The keypad is also standard 4x4 which has 8 pin connector. The smoke detector is powered by standard E-block 9V battery. The motion sensor is powered by 2 AAA 1.5V battery in serial.
Existing Patents, Copyrights and Trademarks
The magnetic contact switch is manufactured by SECO-LARM? The motion detector is manufactured by SPY GEAR. The smoke sensor is a little bit hard to identify because we do not have the original box, but we believe it manufactured by FAMILY GARD?
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