The Design Of House Fire Warning System Based On Zigbee

With the development of technology and the pursuit of high standard life quality, more and more electronic household appliances are available for modern people,which indeed offers people a convenient life. Unfortunately, these advanced technology associated with high power dissipation has been inducing many security risks and even disasters at home. According to the survey from relevant departments, a large number of fire accidents occurring in family house every year severely threatens people’s life, and emphasizes the importance of research on house fire alarming system. The present widely used single sensor based fire alarm system has a high rate of false alarming and expensive installing and repairing cost as well. Thanks to the development of wireless network, it is possible to build wireless fire alarming system in house. Such system has great advantages over the previous ones, such as high stability, easy installation, low cost. ZigBee is one wireless communication technology that is very suitable for application of house fire alarming system due to its unique advantages of short delay and reliable data transmission. In this article, a fire alarming system based on ZigBee wireless sensor network is designed.The whole house fire alarming system is based on "the rule of automatic fire alarm system design" and meets the requirement of regional fire alarm system. The network topology structure of ZigBee can be divided into three categories-star structure, network structure and the cluster tree structure. According to common family room layout, this system adopts the cluster tree structure. Chip CC2430will be used as the core in this design. The coordinator node is used to process and analyze the fire signal, together with the router node for transmitting and monitoring the fire signal and the terminal node for monitoring and sending a fire signal. Once the coordinator node detects the fire, one signal will be sent to the client. Meanwhile, a broadcast message will be sent to all the nodes to trigger the alarm. In addition, the fire information will be sent to the user’s mobile phone by GSM. The client receives coordinator fire information, which is displayed to the interface and is sent to the monitoring center of community through Internet. According to the fire information, the monitoring center is able to arrange rescue timely to protect people from fire. In order to effectively reduce the missing occurrence of fire, the system uses smoke sensor, CO sensor and the pyroelectric infrared sensor to monitor the fire signal. The system applies a weighted algorithm to determine whether there is a fire or not, which can keep the false alarming rate in a low level.The CC2430chip has21I/O general ports, and is particularly suitable for multi-input system design. This paper takes CC2430system on a chip as the core to the design of wireless sensor network node, and develops external interface module of CC2430chip, boost module, smoke sensor module, CO sensor module, the pyroelectrical infrared sensor module, and the alarm module. The output voltage of CC2430is3.3V and will be transformed to5V by the boost module in order to provide stable voltage for sensor. Three kinds of sensors monitor the fire signal separately, and then the comparator transforms the fire signal into high low-level voltage which will serve as the input of CC2430.The whole hardware design should meet the requirements of reliability, real time and low cost.On the basis of the hardware design, this article transplants Z-Stack protocol and designs to meet the house fire alarming system performance software through the IAR Embedded Workbench7.3OB development environment. The software design includes the node network, and the acquisition, transmission and management of information, and so on. The system uses Visual Basic6.0development environment to design the client and monitoring system. The client is used to locate the fire spot, and also sends the fire information to the monitoring system. The monitoring system shows the fire information from the client. The fire information is stored in database.Finally, the entire system is tested in the laboratory. It realizes the function of the house fire alarm system, effectively reduces the rate of false alarming and omitting and is very effective for home fire alarm.