Burglar alarm system

 

A burglar alarm monitoring system will carry out the following actions:
• The system is activated by keying in a password on a keypad.
• The infra-red sensor picks up the movement of an intruder in the building.
• The acoustic sensor picks up sounds such as footsteps or breaking glass.
• The pressure sensor picks up the weight of an intruder coming through a door or
through a window.
• The sensor data is passed through an ADC if it is in an analogue form to produce
digital data.
• The computer/microprocessor will sample the digital data coming from these
sensors at a given frequency (e.g. every five seconds); the data is compared with
the stored values by the computer/microprocessor.
• If any of the incoming data values are outside the acceptable range, then the
computer sends a signal to:
• a siren to sound the alarm, or
• a light to start flashing.
• A DAC is used if the devices need analogue values to operate them.
• The alarm continues to sound/lights continue to flash until the system is reset with a password.