【正文】 rm system based on single chip microputer, which is suitable for many kinds of public places. The system takes the AT89C51 as the main controller, and the DS18B20 temperature sensor is a temperature sensor, the ion sensor is a sensor, and the signal can be converted into a detectable signal. Then the sensor output of the electrical signal into the A/D conversion circuit, plete the smoke sensor and temperature sensor output analog signal to digital signal conversion, and then by the microcontroller to determine whether the scene of fire. If a fire occurs, the system will drive the buzzer and LED indicator alarm. The system mainly by the smoke sense data collection module, MCU control module, drive the sound and light alarm module, as the core and high sensitivity of ion smoke sensor and temperature sensor with high performance single chip, and the use of sound and the indicator lamp two types of alarm, alarm, greatly improve the accuracy and reliability of the system. Key words: fire alarm smoke detector AT89C51 MCU DS18B20 四川師范大學成都學院課程設計報告 III 目 錄 1 緒論 ................................................................................................................ 1 課題研究背景 ......................................................................................... 1 國內外火災報警器研究歷史 ............................................................................................... 1 火災報警技術的發(fā)展趨勢 ................................................................................................... 3 2 火災報警器系統(tǒng)總體方案設計 ..................... 3 火災 產生的原理 ................................................................................................................... 4 系統(tǒng)設計要求 ....................................................................................................................... 4 3 系統(tǒng)硬件設計 ................................... 5 煙感傳感器 .......................................................................................................................... 5 煙感傳感器選擇 ....................................................................................................... 5 離子式感煙探測器介紹 ........................................................................................... 5 溫度傳感器 .......................................................................................................................... 6 溫度傳感器選擇 ....................................................................................................... 6 DS18B20 工作原理 .................................................................................................... 6 DS18B20 特性 ............................................................................................................. 7 DS18B20 注意事項 .................................................................................................... 8 單片機芯片的選擇 ............................................................................................................... 8 AT89C51 簡介 ............................................................................................................ 9 AT89C51 管腳功能說明 .......................................................................................... 10 4 火災報警器軟件實現(xiàn)與調試 ...................... 11 信號處理電路 ...................................................................................................................... 11 聲光報警電路 ...................................................................................................................... 12 聲報警