小型称重系统的设计

摘要

传统的称重在市场上已经满足不了我们的需求。我们一直希望紧凑，测量准确，显示直观，便宜的电子称重装置可取代传统的称量工具。电子称重机便应运而生，凭借称重仪表无法取代传统的功能，如称量方便，准确，自动化控制，操作简单，广泛应用于人们的生活，工业生产中。

电子称重装置以MCU作为中央控制单元，由通过称重传感器进行模数转换单元，在配以键盘、显示电路及强大软件来组成。本选题采用压力传感器来收集由于通过电压放大电路产生的微弱信号的压力变化，通过A/D转换器转换成数字信号后，将数字信号送入微处理器。经微控制器的适当处理后，将模拟量转化为数字量输出，控制器接受来自A/D转换器输出的数字信号，将数字信号转换为物体的实际重量信号，并传送到显示单元。此外，项目可通过键盘涉嫌价格被设置。这种高精度智能电子称重器体积小，准确，便于携带，重量函数集的质量和价格计算功能于一体，满足商业贸易和居民家庭的需要。

关键词：电子称重器；单片机；称重传感器

Abstract

Traditional weighed on the market has failed to meet our needs. We always wanted a compact , accurate measurement , intuitive display, cheap electronic weighing device can replace the traditional weighing tools. Electronic weighing machines have come into being , by virtue of weighing instruments can not replace the traditional features, such as weighing convenient, accurate , automatic control , simple operation, widely used in people's lives and industrial production.

Electronic weighing means as a central control unit MCU from the load cell through the analog-digital conversion unit configured with a keyboard, a display circuit and powerful software components. The topic using pressure sensors to collect the pressure produced by the change of the voltage amplifier circuit weak signals by A / D converter into a digital signal, the digital signal is fed to the microprocessor . After appropriate treatment of the microcontroller , the analog to digital conversion of the output , the controller receives the digital signal from A / D converter outputs a digital signal is converted to the actual weight of the object signals , and transmitted to the display unit . In addition , the project can be set via the keyboard alleged price . This high-precision electronic weighing devices small smart , accurate, easy to carry , quality and price calculation of the weight function set functions, commercial trade and residents to meet the needs of families .

Keywords: electronic weighing devices ; SCM ; weighing sensors

目录

摘要 ................................................................................................................................... I Abstract .............................................................................................................................. II 第一章绪论 . (3)

1.1 选题的背景和意义 (3)

1.2 国内外研究现状 (3)

1.3 电子称重器介绍 (4)

第二章小型称重系统方案设计 (6)

2.1系统概述 (6)

2.2系统组成 (7)

2.2.1 AT89C51单片机 (7)

2.2.2 传感器的选择 (8)

2.2.3 放大电路的选择方案 (9)

2.2.3 数码管 (10)

2.2.4 键盘输入 (11)

第三章系统硬件的设计 (12)

3.1电源电路 (12)

3.2晶振电路及复位电路 (13)

3.3 LED显示电路 (13)

3.4 传感器放大电路 (14)

3.5 键盘和显示的设计 (15)

3.6 报警电路的设计 (16)

第四章系统程序的设计 (17)

4.1 C语言在单片机中的应用 (17)

4.2 电子称重器的软件设计与实现 (17)

4.3主程序流程图 (18)

第五章总结和展望 (20)