摘 要：随着社会的不断发展，火灾发生的频率也越来越高。自动火灾报警系统就是为了保障人民生命财产安全而发明的，本文针对传统火灾自动报警系统功能少、性能差、不能满足发展需求等一系列问题，设计了一种基于AT89S52单片机的火灾自动报警系统。78723

本次选用ATMEL公司的AT89S52单片机，AT89S52单片机具有低功耗、高性能等特点。本次设计选用温度传感器与烟雾传感器对信号进行采集，温度传感器采用DS18B20数字温度传感器，该传感器可直接将温度信号转换成数字信号给单片机，并且能设定温度报警值，电路构造简单，功能较齐全。烟雾传感器选用MQ-2型半导体可燃气体敏感元件烟雾传感器，该传感器属于气敏传感器，将可燃气体在空气中的含量转换成电压或者电流信号，通过ADC0832将模拟量转换成数字信号后发送到单片机，最后通过液晶显示模块显示出气体的浓度与实时温度。本系统采用C语言对其设计，并用Proteus进行仿真，实现了自动报警的功能。

毕业论文关键词：传感器，AT89S52，信号处理，火灾报警器

Abstract：With the continuous development of society, the fire frequency is also more and more high。 Automatic fire alarm system is created in order to safeguard the people's life and property safety, this paper in view of the traditional automatic fire alarm system function are few, performance is poor, can not meet the development needs of a series of problem, design the microcontroller AT89S52 fire automatic alarm system based on。

The selection of ATMEL Corporation AT89S52 SCM, AT89S52 MCU with low power consumption, high performance。 The design of selection of temperature sensors and smoke sensor signal acquisition, temperature sensor using DS18B20 digital temperature sensor, the sensor can be directly to the temperature signal is converted into digital signal to the microcontroller, and can set temperature alarm value, simple circuit structure, function is complete。 Selection of smoke sensor MQ-2 semiconductor combustible gas sensitive element smoke sensor, the sensor belongs to the gas sensor, combustible gas content in the air will be converted into voltage or Current signal, through the ADC0832 analog is converted into digital signal is sent to the MCU。 Finally through the liquid crystal display module shows the gas concentration and temperature in real time。 The system using C language to design, and use the Proteus simulation, the realization of the automatic alarm function。

Keywords：The sensor, AT89S52, The signal processing, the fire alarm 

目  录

1 绪  论 4

1。1 发展背景及研究意义 4

1。2 国内外现状和发展动态 4

1。3 研究内容与设计指标 4

1。4 设计方案 5

2系统总体设计和硬件的设计 5

2。1 系统总体设计 5

2。2 系统硬件的设计 6

2。2。1 控制模块设计 6

2。2。2 晶振电路 6

2。2。3复位电路 7

2。2。4 最小系统电路图 8

2。2。5显示模块 9

2。2。6温度采集模块 9

2。2。7 气体采集模块 10

2。2。8 A/D转换模块设计