An automatic fire alarm system is designed to detect the unwanted presence of fire by monitoring environmental changes associated with combustion. In general, a fire alarm system is classified as either automatically actuated, manually actuated, or both.
Automatic fire alarm systems are intended to notify the building occupants to evacuate in the event of a fire or other emergency, report the event to an off-premises location in order to summon emergency services, and to prepare the structure and associated systems to control the spread of fire. A key aspect of fire protection is to identify a developing fire emergency in a timely manner, and to alert the building’s occupants and fire emergency organizations.
For more detail: Advance Fire Alarm through Mobile Phone using microcontroller