【正文】 重范圍為0～，重量誤差不大于177。整個系統(tǒng)結(jié)構(gòu)簡單，使用方便，功能齊全，精度高，具有一定的開發(fā)價值。 data acquisition in part by the pressure sensor, signal processing and the first class A / D conversion part。s USB port, simple power supply design. Software part of the application microcontroller C programming language, designed to achieve all the control functions. The electronic weighing scales can realize the basic functions (weighing range is 0 ~ , the weight of error of less than 177。 load cell。 matrix keyboard。 LCD 多功能電子秤3目 錄1 摘 要 ...............................................................................................................................................1目 錄 .......................................................................................................................................................32 前 言 .................................................................................................................................................4 選題背景 ...................................................................................................................................4 電子秤簡介 ...............................................................................................................................5 電子秤的定義 ..................................................................................................................5 電子秤的分類 ..................................................................................................................5 電子秤的計量性能 ..........................................................................................................6 電子秤的特點(diǎn) ..................................................................................................................6 電子秤的發(fā)展方向 ..........................................................................................................73 系統(tǒng)開發(fā)軟硬件概述 .......................................................................................................................7 單片機(jī)的選型 ...........................................................................................................................7 PROTEUS 仿真軟件簡介 ...........................................................................................................9 KEIL 編譯及調(diào)試軟件簡介 ....................................................................................................104 系統(tǒng)構(gòu)成及工作原理 .....................................................................................................................12 系統(tǒng)總體設(shè)計方案比較與論證 .............................................................................................12 本系統(tǒng)的設(shè)計思路 .................................................................................................................13 本系統(tǒng)的功能 ................................................................................................................14 系統(tǒng)設(shè)計方案 ................................................................................................................145 硬件電路設(shè)計 .................................................................................................................................16 單片機(jī)電路模塊框圖 .............................................................................................................16 系統(tǒng)硬件的結(jié)構(gòu)框圖 .............................................................................................................17 穩(wěn)壓直流電源設(shè)計 .................................................................................................................18 傳感器及數(shù)據(jù)采集部分電路設(shè)計 .........................................................................................18 電阻應(yīng)變式傳感器的選擇 ............................................................................................18 數(shù)據(jù)采集采用 HL8 型稱重傳感器 ..............................................................................21 運(yùn)放與 A/D 轉(zhuǎn)換器部分 ............................................................................................. 1 本系統(tǒng)傳感器及 AD 采集部分原理圖 ...................................................................... 5 人機(jī)交互部分 ...................................................................................................................... 5 鍵盤輸入 ...................................................................................................................... 5 輸出顯示 ...................................................................................................................... 6 6 系統(tǒng)軟件設(shè)計 .............................................................................................................................. 8 電子秤秤重子程序設(shè)計 .............................................................................................. 8 主要中斷程序流程圖 ..............