基于單片機(jī)的便攜電子秤系統(tǒng)硬件部分

摘要

隨著微電子技術(shù)的應(yīng)用，市場(chǎng)上使用的傳統(tǒng)稱重工具已經(jīng)滿足不了人們的要求。為了改變傳統(tǒng)稱重工具在使用上存在的問題，在本設(shè)計(jì)中將智能化、自動(dòng)化、人性化用在了電子秤重的控制系統(tǒng)中。本系統(tǒng)主要由單片機(jī)來控制，測(cè)量物體重量部分由稱重傳感器及A/D轉(zhuǎn)換器組成，加上顯示單元，此電子秤俱備了功能多、性能價(jià)格比高、功耗低、系統(tǒng)設(shè)計(jì)簡(jiǎn)單、使用方便直觀、速度快、測(cè)量準(zhǔn)確、自動(dòng)化程度高等特點(diǎn)。本系統(tǒng)以AT89C51單片機(jī)為主控芯片，外圍附以稱重電路、顯示電路、報(bào)警電路、鍵盤電路等構(gòu)成智能稱重系統(tǒng)電路板，從而實(shí)現(xiàn)自動(dòng)稱重系統(tǒng)的各種控制功能。此設(shè)計(jì)所完成的智能稱重系統(tǒng)很大程度上滿足了應(yīng)用需求。

關(guān)鍵詞  ： AT89C51;稱重傳感器;A/D轉(zhuǎn)換器;LCD顯示器

Abstract: With the application of micro-electronics technology, tradition ponderation instrument used in market has been not satisfaction with hunman requirements already. In order to make up for the traditional apparatus shortcoming, we improve the apparatus's control system with intelligence and automation. This system is mainly controlled by microcontroller, the section of height measurement accomplish by supersonic sensor, the section of weight measurement accomplish by weight sensor and A/D transformer, this apparatus have many characteristic such as having more function, consume less energy, small and move easily, low price, measure precisely, the speed is quick, automatic work without people and so on. The system is mainly controlled by the microcontroller AT89C51 the periphery is consist of the circuit of clock and calendar, the circuit of measure height and weight, the circuit of display and print, all of these comprise the circuit board of the intelligent apparatus of height and weight. It can achieve all function of the apparatus.

Key words: AT89C51，ponderation –sensor，A / D converter，LCD display;

目  錄

1 緒 論 1

1.1引言 1

1.2 選題背景和意義 1

1.3 國內(nèi)外電子稱發(fā)展及成果 2

2系統(tǒng)方案設(shè)計(jì) 4

2.1 系統(tǒng)總體設(shè)計(jì)方案比較與論證 4

2.2 硬件的方案設(shè)計(jì)與論證 6

2.2.1 傳感器 6

2.2.2 前級(jí)放大器部分 9

2.2.3 信號(hào)轉(zhuǎn)換 10

2.2.4 控制單片機(jī)的選型 12

2.2.5 顯示模塊 13

2.2.6 鍵盤輸入 15

2.2.7 電源模塊 16

2.3 具體實(shí)施方案簡(jiǎn)介 17

3系統(tǒng)硬件設(shè)計(jì) 18

3.1 AT89C51的主控電路 18

3.1.1 AT89C51簡(jiǎn)介 18

3.1.2 引腳說明 18

3.1.3 電路具體設(shè)計(jì) 20

3.2 信號(hào)放大電路 21

3.2.1 芯片INA126簡(jiǎn)介 21

3.2.2 INA126特點(diǎn)及引腳說明 21

3.2.3 具體電路設(shè)計(jì) 22

3.3 信號(hào)轉(zhuǎn)換電路 22

3.3.1芯片LM331應(yīng)用 22

3.3.2 LM331功能介紹 22

3.3.3 具體電路設(shè)計(jì) 23

4系統(tǒng)軟件設(shè)計(jì) 25

4.1 C語言在單片機(jī)中的應(yīng)用 25

4.2 電子稱的軟件設(shè)計(jì)與實(shí)現(xiàn) 25

4.3主程序流程圖 26

4.4 子程序設(shè)計(jì) 27

4.4.1 V/F轉(zhuǎn)換啟動(dòng)及數(shù)據(jù)讀取程序設(shè)計(jì) 27

4.4.2顯示子程序設(shè)計(jì) 28

4.4.3鍵盤掃描子程序的設(shè)計(jì) 29

結(jié)束語 30

謝  辭 31

文  獻(xiàn) 32