摘 要：随着社会和经济的发展，人们对防火工作愈加重视，目前国内许多大型场所均有完善的火灾报警系统，而小场所如民居场所却很少有火灾报警系统。因此，需要设计一种结构简单、经济实用的家庭火灾报警系统以适应市场的需求。基于单片机的家庭火灾报警系统可以满足结构简单、经济实用的要求，具备火灾报警的功能。93860

本设计以单片机和传感器作为家庭火灾报警系统的核心器件，配合其它器件即可实现火灾感知和声光报警等功能。设计选用STC89C52单片机作为控制器件，选用MQ-2烟雾传感器作为烟雾采集器，选用DS18B20作为温度采集器。家庭火灾报警系统主要由烟雾信号采集电路、模数转换电路、温度信号采集电路、单片机控制电路、显示电路和声光报警电路构成，设计合理、原理简单、价格低廉，使单片机在家庭火灾报警系统的控制中得到充分应用，具有一定的实用价值。基于单片机的家庭火灾报警系统，经济实用，能够满足市场的需求。

毕业论文关键词：单片机，传感器 ，模数转换电路，火灾报警系统

Abstract: With the development of society and economy, more and more people pay attention to the fire prevention work, many large sites have improved the domestic fire alarm system, and the small places such as residential places there is little fire alarm system。 Therefore, it is necessary to design a simple, economical and practical household fire alarm system to meet the needs of the market。 The family fire alarm system based on single chip can meet the requirements of simple structure, economical and practical。

The design of the microcontroller and sensor as the core component of the family fire alarm system, with other devices can realize the fire perception and sound and light alarm function。 The design selects the STC89C52 monolithic integrated circuit as the control device, selects the MQ-2 smog sensor as the smoke collector, selects DS18B20 as the temperature collector。 The family of fire alarm system is mainly composed of a smoke signal acquisition circuit, analog-to-digital conversion circuit, the temperature signal acquisition circuit, MCU control circuit, display circuit and alarm circuit, reasonable design, simple principle, low price, has been fully applied in the control of the microcontroller family fire alarm system, and has a certain practical value。 Family fire alarm system based on MCU, economic and practical, to meet the needs of the market。

Key words: single chip microcomputer，sensor，analog to digital conversion circuit，fire alarm system 

目录

第一章  绪论 6

1。1课题背景 6

1。2课题意义 6

1。3国内外现状 7

第二章  元器件选择 9

2。1设计要求 9

2。2单片机选择 9

2。3烟雾传感器 9

2。4温度传感器 10

第三章  系统的硬件电路设计 11

3。1整体方案设计 11

3。1。1系统概述 11

3。1。2系统框图 11

3。2单片机最小系统 11

3。2。1 STC89C52简介 11

3。2。2最小系统电路 14

3。3烟雾传感器及A/D转换