【正文】 ife, but it can not see, just by feeling it probably only feel the temperature values, traditional pointer thermometer indicates that the temperature, but low accuracy, use is not convenient enough, the display is not intuitive, digital thermometer is made using digital more intuitive understanding of the temperature in the end they want to know is how much. Therefore, the temperature measurement is a very important physical parameters can directly tell people the size of the required temperature. With the development of science and technology of the world, for the temperature measurement requirements bee increasingly stringent, measure the temperature of the environment is also worsening. Temperature measurement is not limited to the indicators go out dressed in the reality of the society, the measurement and control of temperature everywhere, for example, the family can see inside the refrigerator thermostat. But many times, in the harsh environment of the measurement will be subject to a large degree of restriction, especially in industrial control, at this time, the automatic control of the temperature measuremente particularly important. This article is DS18B20 as the temperature sensor and the use of automatic measurement of the current temperature, to be processed by the microcontroller avr mega16 control displays the set temperature and the current temperature and through lCD1602 to, if the temperature exceeds the set temperature, the system will be relatively simple the sound and light alarm. Keywords: SCM, DS18B20, lCD1602, sound and light alarm 4 目錄 1 緒論 .............................................................................................................. 6 課題的背景 ........................................................................................ 6 課題的意義 ........................................................................................ 6 研究的基本內(nèi)容與擬解決的主要問題 ............................................ 7 研究的基本內(nèi)容 ......................................................................... 7 擬解決的主要問題 ..................................................................... 8 2 設計的思路 .................................................................................................. 8 設計基本原理 .................................................................................... 8 設計的基本條件 ................................................................................ 9 溫度報警器的技術(shù)和工作原理 ........................................................ 9 DS18B20 溫度傳感器介紹 ......................................................... 9 DS18B20 的初始化 ................................................................... 10 DS18B20 的寫操作 ................................................................... 10 DS18B20 的讀操作 ................................................................... 11 DS18B20 內(nèi)部結(jié)構(gòu)圖 ............................................................... 11 DS18B20 工作原理 ................................................................... 11 液晶顯示屏 LCD1602 主要參數(shù)技術(shù) ............................................ 12 引腳接口說明表 ....................................................................... 12 LCD1602 的指令說明及時 序 ..................................................... 13 Atmega16 單片機介紹 ....................................................................... 13 3 系統(tǒng)硬件設計 ............................................................................................ 13 溫度傳感器設計 .............................................................................. 13 液晶 LCD1602 顯示部分設計 ........................................................ 14 單片機 ATmega16 原理圖設計 ...................................................... 15 程序燒寫 ................................................................................... 16 電源端口 ................................................................................... 16 串口通訊端的設計 ................................................................... 16 報警設計 ................................................................................... 17 5 按鍵設計 ................................................................................... 17 4 系統(tǒng)軟件設計 ............................................................................................ 18 流程圖 .............................................................................................. 18 5 溫度數(shù)據(jù)處理函數(shù) .................................................................................... 19 DS18B20 初始化函數(shù) ........................................................................ 19 傳感器 DS18B20 的子函數(shù) ............................................................ 19 傳感器 DS18B20 寫命令子函數(shù) ............................................. 20 DS18B20 讀一個字節(jié)數(shù)據(jù)子函數(shù) ........................................... 21 LCD1602 顯示函數(shù) ............................................................................ 23 LCD1602 初始化子函數(shù) ........................................................... 23 LCD1602 寫數(shù)據(jù)子函數(shù) ........................................................... 24 LCD1602 寫命令子函數(shù) ........................................................... 24 按鍵函數(shù) .......................................................................................... 25 主函數(shù) .............................................................................................. 28 6 系統(tǒng)調(diào)試 .................................................................................................... 30 軟硬件調(diào)試以及分析 ...................................................................... 30 參考文獻 .............................................................................................................. 31 附錄 ...................................................................................................................... 32 6 1 緒論 溫度 是 我們?nèi)粘Ｉa(chǎn)和生活中實時在接觸到的物理量，但是它是看不到的，僅憑感覺只能感覺到大概的溫度值，傳統(tǒng)的指針式的溫度計雖然能指示