25-08-2017, 10:12 AM
25-08-2017, 11:56 AM
Security is a big challenge everywhere because thefts are increasing day by day due to insecure and insecure security systems in homes, commercial complexes and industries. Several conventional technologies are available to keep home properties safe from intruders, but most smart home security systems work on wireless GSM communication. These systems provide security against natural, incidental, intentional, involuntary, accidental and human problems, continuously monitoring homes with different sensory systems such as motion, smoke, gas, temperature, glass break or door detectors and fire alarm systems.
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GSM based security system
Home security or home automation can be achieved by adopting central controllers to control home appliances or appliances that detect different variables using appropriate sensors. The main aspect of such a system is a sensory system that collects parameter information such as temperature, fire, human presence, gas, etc., and sends the corresponding data to the microcontroller or any other processor. This controller is programmed in such a way that when these parameters cross their prescribed limits, it sends command signals to several final control devices such as relays, motors and buzzer devices.
This system can be implemented with the use of the following functional blocks:
Sensory System: It consists of several sensors like IR sensors to detect the human presence to open or close the doors; GPL gas sensor to detect gas leak in kitchens - and, a smoke detector to detect the presence of fire. It is also possible to add temperature sensor, camera and other detection devices to improve the safety of homes. These detection values are sent to the microcontroller with intermediate circuits such as the Analog to Digital Converter (ADC).
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Microcontroller: This is the heart of the system in which central data processing takes place. 8051 collects data or information from several sensors and compares them with the appropriate prescribed limits. It is programmed using integrated C or assembler language in the Keil software. Upon receiving the signals from the sensor, take the corresponding course of action by sending commands to the output devices.
GSM Modem: The GSM modem allows the computer to communicate through the mobile network through calls, SMS messages and MMS. It consists of a SIM card and operates through a subscription through a mobile network. It is a highly flexible plug-and-play device capable of connecting to a PC or any serial port of a microcontroller through MAX232IC. This IC is used to convert the logical levels TTL of the microcontroller to a logic level RS232 to allow the communication in series.
Final Control Devices: These devices include buzzers and motors with controller ICs and LCD display. The final control devices generate alarms of different types using buzzers; Fire exhaust doors and operations are controlled using engines. All these devices act on commands directed from a microcontroller.