基于单片机实现高精度电子秤的设计

摘要

称重技术是人类生活中不可缺少的部分，自古以来就被人们所重视。作为一种计量手段，被广泛应用于工业、农业、贸易等各个领域。随着现代文明和科学技术的不断进步，人们对称重技术的准确度要求也越来越高，电子秤产品技术水平的高低，直接影响各行各业的现代化水平和社会经济效益的提高。近年来，电子称重技术取得了突飞猛进的发展，电子秤在称重计量领域中也占有越来越重要的地位，其应用领域也在不断地扩大。尤其是商用电子秤，由于其具有准确度高、反应灵敏、结构简单等优点，被广泛应用于工商贸易、轻工食品、医药卫生等领域。目前，机械秤正在逐步被电子秤取代，这就促使电子秤的研究需要进一步的深入。

本设计是以AT89S51为核心的一种高精度电子秤，系统采用模块化设计法，其硬件结构主要包括：数据采集模块、最小系统模块、电源模块、键盘和显示模块。其中，数据采集模块包括称重传感器和A/D转换电路；最小系统部分主要包括AT89S51和扩展的外部数据存储器；键盘由4×4位矩阵键盘组成；显示部分LM4229液晶显示。软件部分由C语言编程，实现对各部分的控制。该电子秤可以能够显示商品的名称、价格、总量、总价等；能够自动完成商品的价格计算；能够储存几种简单商品的价格；能够具有超重提醒功能。其称重范围为0～5Kg，分度值为0.001g。整个系统结构简单，使用方便。

关键词：电子秤；AT89S51单片机；称重传感器；A/D转换电路；液晶显示

Abstract

Weighing technology is indispensable to human life, since the ancient times attention. As a measurement method, have been widely applied in industry, agriculture, trade and other fields. Along with the development of modern civilization and progress of science and technology, the accuracy of weighing technology requirements are increasingly high, electronic products, technology level, directly influences the level of modernization and professions to improve the economic benefits of the society. In recent years, the electronic weighing technology achieved rapid development, electronic weighing in the metrology area also plays more and more important position, and its applications are constantly expanding. Especially, because of its commercial electronic with high accuracy, senstive reaction, simple structure, etc, have been widely applied in industry and commerce trade, light food, medicine and health, etc. At present, mechanical scales are gradually replaced by electronic, this has led to the further study of electronic.

This design based on AT89S51 at the core of a high-precision electronic systems, modular design method and its hardware structure mainly include: the data acquisition module, the smallest system module, power module, the keyboard and display module. Among them, the data acquisition module including weighing transducer and A/D circuit, The minimum system parts including AT89S51 and extension of external data storage, Keyboard 4X4 by a matrix of the keyboard, LM4229 LCD display section. Software consists of the C programming language, realize the control of each part. The electronic can can show the name of the product, price, quantity and price; etc. Can be finished goods prices. To be able to store some simple commodity prices, To remind function with overweight. The weighing 5Kg, range of indexing value for 0.001 g. The entire system structure is simple, easy to use.

Keywords: electronic, AT89S51, weighing transducer, A/D circuit, LCD display