Development Of Wireless Fire Alarm Controller

Fire alarm systems in modern intelligent buildings play a crucial role in the prevention of fire disasters. They help secure people's lives and property. Their correct design, installation, operation and maintenance can both reduce loss and guarantee the safety of life, so they have become a necessary installation in industrial and civil buildings, hotels, libraries, researching and commercial departments. The traditional fire alarm systems are composed of a controller and detectors, and always transmit signals in the way of wireline transmission. However, the problems of long construction period, high rate of hardware fault and high cost of transmission line puzzle the administrators of fire control. But wireless communication in place of wireline communication can solve these problems effectively.A fire alarm controller is an important part of a fire alarm system. This paper describes a wireless communication module which receives the outside alarm signals through wireless transmission, and overcomes the shortcomings of the traditional wireline fire alarm controller.This wireless fire alarm controller was designed according to the national standard GB4717-93 of the People's Republic of China for the requirements of the fire alarm controller, and it completes the hardware and software of man-machine conversation and wireless communication. The part of man-machine conversation offers a good operation environment for users with the core of C8051F020 MCU. It realizes the functions of storing and transferring the information of fire alarm, displaying time, scanning keyboards, the safe maintenance of system and so on. The part of wireless communication is controlled by AT89C2051 MCU, mainly realizing transmitting and receiving data between controller and other detectors. The external signals received by a wireless module are transmitted to MCU through shaping circuit, and the signals of MCU are transmitted by a wireless module through tone modulation circuit. It realizes wireless communication. This paper still gives a kind of reasonable signal-transmission mode of wireless fire alarm,which not only saves energy but also ensures reliability.