【正文】 02 LCD display screen, the treated by single chip microputer was displayed in the LCD screen, in order to prevent the happening of the accident。 Via a serial port to the PC, the concentration of realtime collected and displayed in the upper unit, so as to realize the upper machine monitoring. The design of a portable bustible gas detector using AT89S52 microcontroller is cheap, stable performance. MQ X series of bustible gas sensors and AT89S52 microcontroller as the core design of bustible gas detector and the design method is simple, the use effect is good. Here are the general design principle of a portable bus tible gas monitor, all hardware circuit and software design. Key words: Gas sensor, AT89S52 singlechip puter and PC, modulus conversion 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)（論文）報(bào)告用紙 目 錄 目錄 引言 ......................................................... 1 1 研究課題 .................................................. 2 研究目標(biāo) ............................................................................................................................. 2 研究方案 ............................................................................................................................. 3 國(guó)內(nèi)外報(bào)警行業(yè)的發(fā)展 ..................................................................................................... 3 2 主要元件簡(jiǎn)介 ............................................. 4 AT89S52 單片機(jī) .................................................................................................................. 4 AT89S52 單片機(jī)簡(jiǎn)介 ..................................................................................................... 4 AT89S52 主要功能 ......................................................................................................... 5 單片機(jī)芯片引腳描述及應(yīng)用 ........................................................................... 5 MQX 系列可燃?xì)怏w傳感器 ............................................................................................... 8 傳感器的定義與組成 ..................................................................................................... 8 系列可燃?xì)怏w傳感器工作原理 ............................................................................. 8 系列可燃?xì)怏w 傳感器操作注意事項(xiàng) ..................................................................... 9 基本測(cè)試回路 ................................................................................................................. 9 芯片 ....................................................................................................................... 10 簡(jiǎn)介 ................................................................................................................... 10 引腳及各引腳功能 ........................................................................................... 10 工作原理 ........................................................................................................... 11 MAX232 芯片 ..................................................................................................................... 12 芯片簡(jiǎn)介 ........................................................................................................... 12 芯片主要特點(diǎn) ................................................................................................... 13 芯片標(biāo)準(zhǔn)應(yīng)用電路 ........................................................................................... 13 液晶顯示 LCD1602 ........................................................................................................... 13 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)（論文）報(bào)告用紙 LCD1602 液晶顯示屏簡(jiǎn)介 ........................................................................................... 13 LCD1602 液晶顯示屏的基本參數(shù)及引腳功能 ........................................................... 14 LCD1602 工作時(shí)序 ....................................................................................................... 15 3 硬件設(shè)計(jì)思路 .............................................. 16 系統(tǒng)基本原理 .................................................................................................................. 16 系統(tǒng)硬件設(shè)計(jì) .................................................................................................................. 16 單片機(jī)最小系統(tǒng) ........................................................................................................... 16 報(bào)警電路的設(shè)計(jì) ........................................................................................................... 19 可燃?xì)怏w傳感 器模塊設(shè)計(jì)與制作 ............................................................................... 19 按鍵模塊設(shè)計(jì) ............................................................................................................... 19 液晶顯示模塊設(shè)計(jì) ....................................................................................................... 20 模數(shù)轉(zhuǎn)換模塊設(shè)計(jì) ....................................................................................................... 20 串口下載模塊設(shè)計(jì) ....................................................................................................... 21 4 系統(tǒng)軟件設(shè)計(jì) ............................................. 22 編程軟件 KEIL 的介紹 ..................................................................................................... 22 系統(tǒng)主程序設(shè)計(jì) .............................................................................................................. 23 系統(tǒng)主程序流程圖 ....................................................................................................... 23 系統(tǒng)主程序設(shè)計(jì)要點(diǎn) ................................................................................................... 24 模數(shù)轉(zhuǎn)換子程序 .............................................................................................................. 24 上位機(jī)界面程序 .............................................................................................................. 24 按鍵程序設(shè)計(jì) ..............................................................................................