Voice and GSM Alert Based Home Security System:
Home security in India has been a major issue, because day by day crime rate is increasing and everybody wants to take proper actions to prevent this crime rate. In addition, there was a need to take the advantage of the technological advancement to automate home so that a person getting off the office does not feel insecure.
The project is aimed at developing the security of Home against Intruders , Gas Leak and Fire . If any of these cases happen while your are outside the home, this Voice and GSM Alert Based Home Security sends SMS to the emergency number provided to it. User can also add unique voice based alert feature in order to provide voice alert to watchman or nearby houses.
In this project we interfaced 8051 microcontroller with Motorola’s C168 GSM mobile phone to decode the received message. The protocol used for the communication between the two is AT command.
The microcontroller pulls the SMS received by phone, decode it, recognizes the
Mobile no. and then switches on the relays attached to its port to control the appliances. After successful operation, controller sends back the acknowledgement to the user’s mobile through SMS.
A GSM module assembles a GSM/GPRS modem with standard communication interfaces like RS-232 (Serial Port), USB etc., so that it can be easily interfaced with a computer or a microprocessor / microcontroller based system. The power supply circuit is also built in the module that can be activated by using a suitable adaptor.
The following section describes the AT-Command set. The commands can be tried out by connecting a GSM modem to one of the PC’s COM ports. Type in the test-command, adding CR + LF (Carriage return + Line feed = \r\n) before executing. Table gives an overview of the implemented AT-Commands in this application.